The Bulletin – October 1968

Quarterly Journal of The Association for Petroleum Acts Administration

E. V. BEEBY

J. BEER

J. BIRKS

R. L. BLOOR

J. W. FRID H. GRIFFITHS D. HALL

THE ASSOCIATION FOR PETROLEUM ACTS ADMINISTRATION

Chairman: C. T. PEACOCK Vice-Chairman: B. W. C. THACKER

Council:

Rugby R.D.C. 2071

G. H. HARVEY

Worcester City 23156 J. W. HEWISON

Chesterfield B. 2825

T. KERR

Dudley C.B. 55433

Havant and Waterloo U.D.C. 6311

Glanford Brigg R.D.C. 2041

Kidderminster B. 3080 H.R. MELLOR Blackpool C.B. 23848

Cambridge City 58977

C.R.PESKETT Godalming B. 191/2

Walsall C.B. 25661 R. E. J. RODEN Birmingham City 021-23.6 9944

Newcastle-under-Lyme B. 60161 J. SHORT Paisley Burgh 5400

Officers:

Hon. Secretary/Treasurer:

Hon. Editor: L.A. CAVE R. P. HOLDAWAY

Liaison Officer: G.N.DEAN

Hon. Electrical Adviser:

Hon. Legal Adviser: J. A. SHARP P. D. WADSWORTH

EAST MIDLAND NORTHERN

NORTH WESTERN ScornsH

Soum EASTERN

SoUTH EAST MIDLAND WEST MIDLAND YoRKSHIRI!

Branch Secretaries: J. BIRKS, B. W. C. THACKER, H. R. MELLOR, J. SHORT, C. R. PESKETT, R. E. DUST, G. H. HARVEY, C. T. PEACOCK,

OCTOBER, 1968

The Bulletin

Published quarterly by the Association for Petroleum Acts Administration

Opinions expressed in this journal are not necessarily the views of the Association

Editor: R. P. HOLDAWAY WEIGHTS AND MEASURES DEPT GUILDHALL, SHREWSBURY

Subscription: 30s. per annum

CONTENTS

TALKING POINT 86 NOTES AND NEWS 86 LETTERS 88

CONVEYANCE OF INFLAMMABLE LIQUIDS-C. L. DAVIDS 88 W. C. R. DALE 89

BANISH PUMPS-M. J. CHAPMAN 91 SELF SERVICE-J. G. FRENCH 93 W

THE NATURE OF PETROLEUM SPIRIT AND ITS HAZARDS-J. R. HUGHES 98

THE TESTING OF NEW AND EXISTING PETROLEUM SPIRIT STORAGE TANKS-J. BEER 102 GAS PRESSURE TESTING OF T ANKS-C. L. DAVIDS 106 BRANCH MEETINGS : EAST MIDLAND SOUTH EASTERN THROUGH THE PIPELINE LEGAL PROCEEDINGS

Chairman: C. T. PEACOCK Honorary Secretary/Treasurer: L. A. CAVE Liaison/Advertisement Officer: G. N. DEAN

106 108 109 I 10

talking point

THE MODEL CODE

The long awaited Model Code, Parts I and II, made its appearance during August. Both parts have been prepared by the Standing Advisory Committee on Dangerous Substances, and an appendix to Home Office Circular No. 182/1968 (Fire Service Circular No. 36/1968) adequately summarises the more important revisions made to the previous edition circulated some ten years ago.

On a first reading of its provisions our reaction was almost one of disbelief. To anyone brought up on the sacrosanctity of the twenty feet safety distance, the use of steel only for the construction of tanks, the need for concrete or brick chambers, the provision of wells at can stores and the strict siting and layout of storage tanks at major installations, this is liberalisation indeed.

As expected, selfcservice, both attended and unattended, receives a special mention. The general note advising licensing authorities to bear in mind that local conditions may make a site unsuitable for self-service operation and suggesting that regard should be paid to surrounding risks and the layout of the installation, goes a long way to allay our anxiety regarding a 4/- minimum delivery from an unattended self-service pump.

It is emphasised that the code is issued only for guidance. Nevertheless, we believe it the duty of licensing authorities to carefully consider the recommendations made and if needs be, adopt those provisions necessary and essential for the public safety.

Over the past few years the Association has published numerous Codes and Conditions, and these have, par- ticularly in the absence of any up-to-date official direction, been welcomed by members. That these codes followed conventional lines cannot be denied, but circumstances prevented the expression of a more advanced viewpoint.

Development in the technological field will continue and there will be a need to keep the Model Code under review. 1:his. has the machinery and the will to go on with its policy 0f keeping abreast of such developments and to this end we welcome an invitatiori from the Institute of Petroleum that a sub-committee of the Association's Technical Committee should meet periodically with representatives of the Institute's Working Party 'A' to discuss mutual problems.

notes and news

New Members

Amersham

RDC Bucks. H

Blandford Forum MBC Dorset s Bolton CBC Lanes. F Brackley RDC Northants. H Bridgwater MBC Somerset H Easthampstead RDC Berks. H Hazel Grove and Bramhall UDC Cheshire s Merthyr Tydfil CBC Glamorgan F Wigan CBC Lanes. F

Officers

C. L. Davids, Greater London Council p L. C. Eden, Bullingdon RDC Oxon s L. Wilson, Denton U DC Lanes. H

Associate Members

A. J. Bayliss & Sons, Pump and Tank Engineers, 30 Clee Avenue, Kidderminster.

Hampshire County Fire Brigade, Chief Fire County Fire Brigade Headquarters, The Castle, Wmchester, Hants.

Kent County Fire Brigade, Chief Fire Officer, County Fire Headquarters, Tovil, Maidstone, Kent.

Lancashire County Fire Brigade, Chief Fire Officer, Fire Brigade Headquarters, Fulwood, Preston, Lanes.

Arieh Menchikovsky, Operations Sonol Israel Ltd., P.O.B. 214, 8 Habankim Street, Haifa, Israel.

Somerset County Fire Brigade, Chief Fire Officer, Hestercombe House, Cheddon Fitzpaine, Taunton, Somerset.

S. Stam, Representative, OPW-Dover (Europa) N.V. Bijlmereerstraat I, Hoofddorp, Netherlands.

Retirements

Mr. R. Bentley, O.B.E., Ch.ief Fire C?fficer, Bolton Fire Brigade, has retired after 20 years service.

Mr. F. G. Jones, M.B.E., Chief Public Inspector, Cuckfield R.D.C., has retired on: grounds of ill health.

We wish these gentlemen a long and happy retirement.

Appointments

Mr. R. H. Eveleigh, Deputy Borough Engineer, Pontefract, has been promoted Borough Engineer and Surveyor.

Mr. G. A. Hodgkinson, Chief Fire Officer, Dewsbury, has been appointed Chief Fire Officer, Bolton, in succession to Mr. R. Bentley.

Mr. R. E. Platt, Deputy Chief Public Health Inspector, Crewe, has been appointed Chief Public Health Inspector and Cleansing Superintendent in succession to Mr. J. Gaskell, appointed Deputy Director of Cleansing, City of Westmmster.

Mr. R. S. Relf, Deputy Chief Public Health Inspector, Cuckfield R.D.C., succeeds Mr. F. G. Jones as Chief Public Health Inspector.

Mr. P. West, Deputy Chief Public Health Inspector, Godstone R.D.C., has been appointed Chief Public Health Inspector in succession to the late Mr. A. H. Sewell.

Obituary

We regret to report the death of:

Mr. R. L. Bloor, Chief Inspector of Weights and Measures, Kidderminster. Mr. Bloor was a founder member of the Association (previously the West Midlands Petroleum Group) and had been a member of its Council since its inception in 1958. He was Chairman of the Education and Publications Committee and will be remembered by many students who attended Attingham College, as one who so efficiently and quietly contributed to their welfare and comfort. His loss is a heavy blow to this Association. We offer sincere condolences to his widow and family.

Mr. T. B. Hine, Chief Inspector of Weights and Measures, Canterbury C.B.C.

Mr. A. H. Sewell, Chief Public Health Inspector, Godstone R.D.C.

Change of Address

Associate Members

Engineering Services (Glasgow) Ltd., 8 Incle Street, Paisley. (D. M. Campbell, General Manager).

Publications

The Inflammable Liquids (Conveyance by Road) Regulations, 1968, S.I. 1968 No. 927-9d.

The Inflammable Liquids (Conveyance by Road) (Labelling) Regulations, 1968, S.I. 1968 No. 928-l/3d.

Model Code of Principles of Construction and Licensing Conditions (Part I) for the storage of Cans, Drums and other Receptacles-Petrol Filling Stations. H.M.S.O., 3/- net.

Model Code of Principles of Construction and Licensing Conditions (Part 2) for Distributing Depots and Major Installations. H.M.S.O., 2/- net.

Report of H.M. Inspector of Explosives for the year ended 31st December, 1967. H.M.S.O., 5/- net.

Avoidance of Water Pollution by Oil-Enquiries to the Secretary, Oil and Industries Working Group, Institute of Petroleum, 61 New Cavendish Street, London, W.l.

Secretary's Notes

The following back numbers of The Bulletin can be obtained from the Hon. Secretary, 5/- each:

April 1964 Vol. 2 No. 4 1

October 1964 Vol. 3 No. 2 1 January 1965 Vol. 3 No. 3 2 April 1965 Vol. 3 No. 4 6 July 1965 Vol. 4 No. 1 I

January 1966 Vol. 5 No. 1 1 April 1966 Vol. 5 No. 2 11 July 1966 Vol. 5 No. 3 I October 1966 Vol. 5 No. 4 9

Will all Members, Associate Members and Bulletin Subscribers in arrears with their subscriptions please arrange clearance before 31 st October, 1968.

The Technical Committee is now actively engaged in revising the Association's various Recommendations, Codes and Conditions in the light of the new Home Office Model Code.

World's Biggest Ship Named

In a burst of champagne, a wail of sirens and a flutter of pigeons at Yokohama, the '._Vorld's ship _was named Universe Ireland by the wife of the Pnme Mm1ster of Ireland.

The Universe Ireland, 312,000 tons deadweight, is the first of three tankers to be delivered to National Bulk Carriers Inc. (NBC) of the United States for the Gulf Oil Corporation.

The vessel which is listed at 148,8 JO gross tons, was built by Ishikawajima-Harima Heavy Industries o[ Japan at a cost of about £9,000,000. Her overall length 1s 1,135 feet, breadth 173 feet and draught 78 feet.

New Thinking for Fuel Tank

Eurogauge Co., Ltd., is now . advocatmg the use .of capacitance equipment for all 011 storage tank gaugmg and control.

Advantages of the are stat_ed to _includ_e the intrinsically safe probe c1rcmtry-depth umt meters-no maintenance and no nsk of creepmg aries, as interconnections are by cable only. In '.1dd1t1on minimum and maximum level probes may also be mst_alled independently of depth measuring probes and ancillary equipment.

The depth indicator unit may be located at a. distance of up to 50 yards from the storage tank and reqmres only a low electricity supply outlet.

New Fire Fighting Technique

A new technique for fighting fires on supertankers is now in operation at BP's Isle of Gram _refinery. the fire-fighting tug Keverne. It is fitted with a 60ft. tripod tower designed and built by John I. Thorny_croft & Ltd., to carry a remote-controlled fire-fightmg momtor.

As tankers increase in size a serious problem faces operators of fire-fighting tugs. wl!en thrown horizontally will reach only 100 feet m still air, about I 50 feet if directed downwards. Directing the jet high into the air will have some measure of success in still air, though the slightest air disturbance is liable to deflect and scatter the foam. To be really effective the jet must be sited at least 50 feet above the waterline.

LATCHED AUTOMATIC CUT-OFF NOZZLES

I share Mr. Hewison's experience and misgiving regarding item (vi) of the Home Office Circular-the 'drive away' test. Tests in Margate were carried out with the Elaflex Type ZVA 19 Mark 7 nozzle on three occasions. In the first instance the nozzle tested made a dent in the rear wing of the car concerned, in the second the flexible hose between pump and nozzle stretched, broke and had to be replaced; the petrol tank on the car was pulled from its mounting and the filling pipe bent out of shape. When testing the third nozzle the flexible hose lashed back, hit an adjacent petrol pump and smashed the glass casing and dial.

It was very clear there ought to be some better way of carrying out such tests because, quite apart from the resulting damage, the relationship between enforcement officer and garage proprietor became a little strained ; particularly when the proprietor, not unnaturally, pointed out that while he is required to exhibit notices forbidding cars to be refuelled with an engine running, these tests required a car (with engine running) to fracture the nozzle coupling with consequent spillage of a small amount of petrol.

Correspondence with the Home Office elicited the opinion that provided satisfactory assurances as to the safeguards built into the equipment and the tests carried out by the manufacturers themselves on each piece of equipment are received, there is no reason why a licensing authority should not regard the manufacturer's statements as sufficient evidence that the nozzle in question meets the requirements laid down.

Conveyance of Inflammable Liquids

A GUIDE TO THE REGULATIONS

C. L. DAVIDS, LI.Fire E.

. The object of this guide is to indicate when the regulat10ns apply, and what the exemptions are. Details of the requirements can be obtained from the regulations.

These regulations do not replace the existing Petroleum Spirit (Conveyance by Road) Regulations, 1957 or The Carbon Disulphide (Conveyance by Road) Regulations 1958 '

I. The Petroleum (Inflammable Liquids) Order, 1968

Came into force on I st August, 1968, and applies certain sections of The Petroleum (Consolidation) Act, 1928 to: (a) Certain liquids named in the order. (All Inflammable).

It was further pointed out, that upon any destructive test, there is no guarantee that any replacements would work and in this situation a reasonable view might be, that if the device is satisfactory when it is new, then it will continue to be satisfactory throughout its working life.

Under the circumstances I propose, therefore, to add an additional condition to our licences to store petroleum spirit, requesting initial production of a certificate from the manufacturers before a latched nozzle is fitted, and 'at such other times as the Chief Petroleum Officer may request'. This is a solution, but to my mind, far from satisfactory.

Margate

CAR PORTS

U. A. BANCROFT

I would very much appreciate the observations and comments of your readers on a conflicting point arising out of legislation with respect to Car Ports.

The Petroleum Regulations classify a small domestic garage as a petroleum store and impose certain conditions and restrictions which conflict with Building Regulations in respect of such garages and car ports. How do we enforce compliance with both forms of legislation ?

The difference being thus: a car port attached to a dwelling is permissible when covering a door and/or window, yet the Petroleum Regulations state that an isolation of ten feet is required between a dwelling and a door opening into a petrol store.

I have in the past reg uired any door or window covered by a garage to have a fire resistance of half an hour but can find no authority to continue this practice in the light of the third amendment to the Building Regulations. Sutton in Ashfield U.D.C. F. H. MOLYNEUX

(b) Any mixture containing any of these liquids if the Flash Point of the mixture is below 73°F.

(c) Certain solutions named in the order if the Flash Point is below 73°F.

This Order gives the Secretary of State power to make the following Regulations:

2. The Inflammable Liquids (Conveyance by Road) Regulations, 1968

Came into force on lst October, 1968, and makes operational requirements for the conveyance of the liquids mentioned above. It does not apply Petroleum Spirit or Mixture, or to Carbon Disulphide.

Reference: Regn. I Regn. 2 Regn. 3 Regn. 4 Regn. 5

Regn. 7(h) Regn. 7(a) Schedule Regn. 7

REQUIREMENTS

Prevention of spillage.

No smoking or naked flame.

No unsafe lights or substances. Fire extinguisher required.

Vehicle owner must ensure that employees are acquainted with Regulations.

EXEMPTIONS

If total quantity on vehicle is not more than 250 kilos (551.3 lbs.).

If all the liquid is contained in "Receptacles" as defined.

No exemptions for Acetaldehyde or for Tank Wagons.

3. The Inflammable Substances (Conveyance by Road) (Labelling) Regulations, 1968.

Came into force on lst October, 1968, and make requirements for labelling vehicles and containers used for all the liquids mentioned above (Para. 1) and, in certain cases, Petroleum Spirit (and Mixture), and Carbon Disulphide.

REQUIREMENTS

Reference: Regn. 2, Schedule I Part I

Schedule 4 Regn. 2(2) Schedule 1, Part 2 Regn. 3

Schedule 2, Para. 3 Regn. 3, Schedule 2 Paras. 1 and 2 Regn.4

Regn. 5(1)

Regn. 5(2) Schedule 3 Regn. 3

Regn. 6(a) Schedule 3 Regn. 6(b) Schedule 3

Details:

All Vehicles including Tank Wagons and Petroleum, to display "Flame Symbol" (20 ems. sq.) fore and aft, centrally, high as possible. Flame Symbol-details and sizes.

Tank Wagons only, not Petroleum, labeJied with name of substance carried (letters 10 or 5 ems.). Containers, including Petroleum, must display "Flame Symbol" (10 ems. sq.).

Containers, excluding Petroleum must be labeIIed with name of substance. '

Owners must ensure that employees are acquainted with Regulations.

EXEMPTIONS

Vehicles not Tank Wagons: If total quantity not more than 250 kilos provided containers comply with Regulations, or if all the liquid is contained in "Receptacles" as defined.

Containers, if they contain not more than I kilo or if a "Receptacle" as defined or an outer container with not more than 30 kilos of "Receptacles".

Winchesters: "Flame Symbol" only required.

Note.-None of the above exemptions apply to Acetaldehyde, Carbon Disulphide or to Tank Wagons.

Petroleum Spirit

Labelling containers is required by Section 5 Petroleum Act. The above Regulations require that the "Flame Symbol" also be displayed if they apply to the conveyance of that Petroleum Spirit.

The of petroleum spirit is subject to the Spmt (Conveyance by Road) Regulations, 1957, however, do not apply if the quantity conveyed ts not more than 32 gallons in cans or 50 gallons in one steel barrel.

exemption is _carried on in the above Regulations, so tf the total quantity of Petroleum Spirit carried is not more than these amounts, none of the Regulations apply to the Petroleum Spirit (or mixture).

Carbon Disulphide

The Conveyance of Carbon Disulphide is subject to the Carbon Disulphide (Conveyance by Road) Regulations, 1958, as amended by the Regulations of 1962.

The exemption under these regulations is not more than 28 lbs. total with not more than 7 lbs. in one container. This exemption is continued.

Hence the above Regulations (i.e. The Inflammable (Conveyance by Road) (Labelling) Regulat10ns). will not apply to Carbon Disulphide if the total quantity on the vehicle is within the exemption quoted.

A.D.R.

W. C. R. DALE. A.F.lnst.Pet.

On 29th December, 1967, Portugal acceded to a European Agreement concerning the International Carriage of Dangerous Goods by Road (A.D.R.). She was the fifth country to do so. This meant that the Agreement came into force one month later on 29th January, 1968, and the technical Annexes to the Agreement became operative a further six months afterwards on 29th July, 1968.

The British Government has made no secret of its intention to adopt and adapt suitable provisions of the Annexes and to include them in domestic legislation. It has been part of the task of the Standing Advisory Committee on Dangerous Substances to advise the Home Secretary on this matter.

The Petroleum (Inflammable Liquids) Order, 1968

The A.D.R. Annexes became operative on 29th July, 1968. It is not surprising therefore to find the Petroleum (Inflammable Liquids) Order, 1968, taking effect from lst August, 1968.

The Order applies some of the of the Petroleum (Consolidation) Act, 1_928, to liquids and 5 solutions, all of which are hsted (with alternative names) in the to the Order. Most ticularly the provisions _of Sect10n 6 of the Act are apphed to the liquids and solut10ns. '!'he of 1s thus empowered to make Regulat10ns govermng their conveyance be road.

The Petroleum (Carbon Disulphide) Order, 1968

Jn order to clear the way for Regulations, a little tidying up operation was necessary. The Petroleum (Carbon Disulphide) Order, 1968, achieves this by excluding disulphide in cou.rse of conveyance from the provisions of Sect10n 5 c:>f Petroleu_m (Consohdat1<;m) Act, 1928. Thus the of yarymg sets of labellmg requirements to carbon disulphide m course of conveyance is avoided. It will be recalled !hat the (Carb?n Disulphide) Order, 1958, apphed Sect1011 5 (with some modification) and Sectton 6 of the 1928 Act to carbon disulphide.

The Inflammable Liquids (Conveyance by Road) Regulations 1968

The Secretary of State has not been slow to make Regulations in pursuance of his new powers the Inflammable Liquids Order. The of what promises to be a series is the Inflammable L1qu1ds (Conveyance by Road) Regulations, 1968.

The purpose of the Regulations is to impose certain elementary safety preca_uti<;>ns in co1?nection with the carriage of There is the usual ban on smoking and potential 1gmt1on sources; care must now be taken to avoid spilling, and a fire extinguisher must be carried. The owner of a vehicle has a duty to acquaint his employees with the provisions of the Regulations.

If one is conveying acetaldehyde, there is no exemption which one may enjoy. The same is true if one uses a tank wagon or tank trailer for the conveyance of any quantity, no matter how small, of an inflammable liquid. On the other hand, one is not caught by the Regulations if: either (a) all inflammable liquids (except acetaldehyde) conveyed are in receptacles containing not more than 1 kilogram, the receptacles are packed according to the Schedule and each package contains not more than 30 kilograms;

or (b) the total quantity of inflammable liquids (except acetaldehyde) conveyed does not exceed 250 kilograms.

These Regulations do not apply to petroleum spirit, petroleum mixture or carbon disulphide. This might be expected because adequate similar provision is already made in respect of these substances by the Petroleum Spirit (Conveyance by Road) Regulations, 1957, and the Carbon Disulphide (Conveyance by Road) Regulations, 1958 and 1962. The effect, however, is that one can convey on a single vehicle, 50 gallons of petrol in a barrel, 28 lbs. of carbon disulphide in seven pound containers and 250 kilograms of any other inflammable liquid except acetaldehyde and yet have no need to comply with the safety requirements of any of the three sets of Regulations.

The Regulations are effective from lst October, 1968.

The Inflammable Substances (Conveyance by Road) (Labelling) Regulations, 1968

To meet a long felt need that the fire service, the police and any other emergency service should have adequate warning that a particular vehicle is carrying a dangerous load of inflammable liquids, the Secretary of State has introduced the Inflammable Substances (Conveyance by Road) (Labelling) Regulations, 1968.

The purpose of the Regulations is to ensure that vehicles conveying inflammable liquid by road are marked with a suitable fire service symbol and the name(s) of the liquid(s) being conveyed. Containers have to be similarly marked but the size of the required symbol is reduced. The symbol selected is the "Flame" sign which is recognised internationally as indicating that a container has inflammable contents.

On a vehicle, the "Flame" symbol has to be placed in a clearly visible position at the front and rear. The positions selected must approximate to the front centre or the rear centre of the vehicle and each must be at the highest practicable point. If the vehicle is a tank wagon or tank trailer, the carrying tank has to be marked with the name of the substance conveyed. Moreover, ifthe carrying tank is compartmented and each compartment contains a different inflammable liquid, then each compartment has to be separately marked with the name of the liquid.

Each outer container of an inflammable liquid has to be marked with the "Flame" symbol and the name of the liquid within it. There is a minor relaxation of this requirement where an outer container encloses not more than six Winchester Quarts packed in the special way laid down in Schedule 3. Jn such a case, the name of the substance can be omitted from the container if no acetaldehyde or carbon disulphide is in the package; this should be a great help to suppliers of laboratories who frequently need to send

out Winchester Quarts of various liquids in a single package.

If a container holds not more than 30 kilograms in individual 1 kilogram units packed in the manner specified in Schedule 3 and does not include acetaldehyde or carbon disulphide, the container does not have to be marked. Moreover, if the only containers on a vehicle comply with the provisions of Schedule 3 and do not contain acetaldehyde or carbon disulphide, the vehicle itself does not have to be marked. The vehicle similarly does not have to be marked if (a) the total quantity of inflammable liquids conveyed does not exceed 250 kilograms, (b) the load does not include acetaldehyde or carbon disulphide and (c) each individual vessel exceeding I kilogram is marked.

Vessels containing acetaldehyde or carbon disulphide or more than I kilogram of other inflammable liquid have to be marked except that vessels in an outer container do not have to be labelled if the outer container is itself marked as required.

Under Section 5 of the Petroleum (Consolidation) Act, 1928, petroleum spirit or mixture containers in course of conveyance have to have a statutory label affixed. There is therefore little point in marking them additionally with the name of the spirit, etc. Suitable exemption is therefore made from this requirement of the Regulations. However, if the vessels exceed 1 kilogram in capacity, they still have to exhibit the "Flame" symbol.

It should be noted that the Regulations do not apply at all to petroleum spirit or petroleum mixture or carbon disulphide if the quantity conveyed is less than the exemption limits laid down in the Petroleum Spirit (Conveyance by Road) Regulations or Carbon Disulphide (Conveyance by R?ad) Regulations, as appropriate. Thus, a vehicle carrymg 50 gallons of petrol in a barrel, 28 lbs. of carbon disulphide in seven pound containers and 250 kilograms of any other inflammable liquid except acetaldehyde need not be marked. The appropriate marking would, however, appear on all vessels exceeding I kilogram in capacity containing the inflammable liquid.

The Regulations are effective from lst October, 1968.

General

There will be more Regulations dealing with. the conby r?ad of inflammable liquids. d.eal111g with vehicle construction are already under d1scuss10n. laying down operational safeguards in.greater detail have yet to be considered. At the same time the task of defining other classes of hazardous substances is proceeding.

Enforcement

The duty of enforcing the Inflammable Liquids (Conveyance by Road) Regulations and the Inflammable Substances (Conveyance by Road) (Labelling) Regulations in a district is laid on the local authority empowered to grant petroleum spirit licences in that district. It is likely that new Orders dealing with other classes of substances will be made in due course under Sect1011 19 of the Petroleum (Consolidation) Act, 1928. If this happens then the petroleum spirit licensing authorities may confidently expect further duties in this field to be laid upon them.

BANISHES PUMPS

Contributed by M. J. CHAPMAN Field Sales Development Manager, BP Retail Division Shell-Mex and BP Ltd., Birmingham

A "l?umples_s" petrol service station has been opened by BP m At Westley Road Service Station, Acocks Green, there are no conventional pumps or islands. Instead, the motorist fills up from electncally operated overhead hoses which are from a canopy covering the whole refuelling area. This development a further stage in BP's proof_ evaluat1<?n of methods and equipment which 1s auned at 1mprovmg forecourt service to the motorist.

(a) The Pump Unit, consisting of a pump driven by a flameproof motor and a metering unit with a transmitter, totaliser and daily totaliser, is housed off the forecourt and alongside the buildings. In the event of a power failure there is provision for manual operation.

(b) The Hose Reel Assembly is mounted beneath the canopy in such a way that the components can be inspected from outside; it contains the main valve, reduction gear, friction clutch , flameproof motor, hose and nozzle.

(c) The Volume Indicator is suspended from the rear edge of the canopy adjacent to the buildings where it can easily be seen by the motorist and the attendant. It includes a device for transmitting and receiving volume information from the pump unit. There is a lso a lamp on the fascia which lights up when the pump motor starts. If this light flashes when the motor starts then there is air in the line which is then banished by purging There is a lso a telecounter in the sales office which repeates the volume indication.

(d) Control System A unit within the m a in building controls the whole electrical system. There are also two buttons situated on the outside wall of the building close to the sales office. The upper one lowers and raises the hose from the canopy and the second is the limiting device overrider.

Westley Road Service Station retails three grades of petrol: BP Super (99 Octane); BP (9_5 Octane) and BP Reaular (91 Octane). The motonst dnves on to one of the 0 three eighteen feet circles on the forecourt each coloured according to the grade of petrol which can be served within a particular circle; red for BP Super, blue for BP Blend and green for BP Regular. The forecourt a ttendant then lowers the hose to head height from the canopy by pressi ng the button on wall. The action of pulling the hose down from_ head height the car's filler cap automatically zero1ses the volume (also colour coded) , sta rts the pump. m?tor a nd lights the "delivery" lamp on the volume 111d1cator.. ln sales office a "delivery" light on the tele-counter 1s also ltghted.

Why do away with petrol pump s ? Because the extra forecourt should, in BP's view, provide a refuellmg operation and less vehicle congestion. If this is then _it _will become possible to contain forecourt activity w1thm a smaller area than is now for efficient site operation. Clearly the greatest potential for the system lie s in town s and cities where la nd costs are high and intensive site development is required. ,

The is manufactured by the Tokyo Tatsuno c:;ompany Limited of J apan, where there mstall at ions in operation. Westley R oad Service Stat10n 1s the first of its kind in Europe. With this the basic of the pump are se parated mto four parts wluch are so sited as to leave the forecourt area completely open:

During refuelling, the amount in gallons being dispensed is recorded both on the volume indicator and also on the telecounter. On completion the attendant places the nozzle in its holder so that it points upwards, presses a button on the hose itself just above the nozzle which is then returned to head height. As a result, the motor stops and the " delivery" light on the volume indicator goes out. At the same time , on the telecounter in the office, the " delivery" light goes out, the "delivery fini shed" light comes on and a buzzer sound s. The telecounter attendant then pres ses a re-set button which results in the " delivery finished" light going out and the buzzer stopping. The forecourt attendant meanwhile presses the button on the wall and the hose is returned to the reel housing beneath the canopy.

If another car is waiting in the circle for the sa me grade of petrol, it is possible to refuel the second car without going through the procedure of press ing the ascend button and then pulling down the hose to re-start the motor. Instead, on completion of the refuelling of the first car, the attendant presses a second button on the ho se-the re-set button. When this is done, the motor stops, the indicator " delivery" light goes out, the "delivery finished" light on the telecounter comes on and the buzzer sounds. When the telecounter operator presses the re-set button on this occasion, the volume indicator is automatically zeroised , the pump motor re-starts and the " deli very" light

comes on. At the end of this refuelling operation, if no other car is waiting for the same grade of fuel, the procedure previously described is carried out. It is also P<;>ssible to operate the system entirely from the forecou:t one attendant only; in which case the telecoun.ter is switched out a nd simply records petrol sales cumulatively. have no plan s to re-equip other sites on the se lines until the completion of a full evaluation of the S{'stem which is being undertaken later this year.

emphasis, of course, will be placed on motorists' react10n to the new style service.

The advantages of the new system on stations with cramped, narrow forecourts where maximum use can ?e made of the available space are obvious. Doubly .so, as is hoped, the system can be adapted to blendmg 111 accordance with BP's policy of making five g'.ades of petrol of varying Octane number and price at each nozzle in order to meet the individual requtrements of each make and model of car.

.Finally,Westley Road Service Station has been equipped with a refuelling system for which no prev10us st a ndards existed in the United Kingdom. We in BP would therefore like to place on record our thanks to the of T.rade, the Home Office and the Birmingham City Council for their helpfulness and co-operation in thi s unique development.

ATTINGHAM 1968

Self Service

J. G. FRENCH, BP Retail Division

I would like to say first of all how happy my colleague and I are to have been invited to talk to you today. Not unnaturally there is sometimes confusion in people's minds how we all into an oil company organisation. I thmk I can explam it best by saying that Mr. Wicks is an engineer and is responsible for the technical development of all types of liquid dispensing equipment used in the retail market-in his case for the three Brands, Shell, BP, an.d National Benzole. I have no such qualification, I am s11nply a marketing man and as such it is my job to try and consider the needs of the modern motorist, analyse them, and relate them to dealer's requirements and then to formulate Company policy.

Self-Service-General

Our subject to-day is Self-Service. There is a tendency for people to look on self-service as some new marketing gimmick. Self-service is not an American invention and it is not In country we have become very' conversant with self-service stores and supermarkets and with ve!1ding ?iachines selling everything from hot coffee to tickets. And_ we now have it in petrol retailingon a comparatively small scale at present. I believe 1t. 1s important at the outset to be clear that two quite different methods of petrol retailing are developing in this country to-day. Firstly, there is post-payment self-service may, 1 be likened to a supermarket operaThe second 1syre-pay11?ent self:service which may be likened to a vendmg machme but mstead of giving a laundry service it dispenses motor spirit.

Post-Payment Self-Service

Let us look at the advantages of this system to the motorist.

F_irstly is a healthy and increasing competition bu1ldmg up 111 the petrol market on the High Streetboth amongst dealers and amongst oil companies. One of the most effective weapons for meeting competition is by cutting price either directly by reducing the retail price or by offering trading stamps-often treble and quadruple. Thus, the first advantage to the motorist is one of savings.

Secondly, on a well-designed site, a post-payment opershould be capable of meeting the requirements of a high flow rate of customers since the motorist does not have to wait whilst the attendant serves the vehicle in front of him, but can get out of the car and help himself.

Thirdly, there is no obligation to tip and the customer can have as much or as little "service" as he wishes. Observation of motorists on self-service sites has shown that they tend to take more care of their cars than do many attendants, especially if the latter are unskilled or disinterested.

Lastly, the motorist has no embarrassment if he only wants one gallon of petrol.

For the dealer the advantages are equally obvious. With the rising costs of labour especially since the introduction of S.E.T. and the difficulty of obtaining good quality staff, there is a continual manning problem.

The competitive advantage gained has already been referred to.

By reducing staff and having only one person at the till both stock and cash control are improved.

Because of the nature of the operation those staff that are required are able to work in better conditions. The console operator is in a warm kiosk or shop and the forecourt supervisor, where one is required, works under a canopy. With better working conditions the dealer is able to recruit higher quality staff, thereby improving the impression which thf'. has of his business. Selfservice petrol reta1lmg 1s modern, and consequently a a modern image is projected. Because the motorist has to get out of his car and pay at the console_ he can then_ be subjected to impulse buymg of merchand1se-accessones, cigarettes, sweets, etc.

The advantages to the oil company follow. An improved Brand image, sales, and, on maxim that "self-service 1s better than no service , an improvement in the customer's attitude towards the company. It would be quite wrong t_o that post-payment selfservice is right for every site. It 1s not. In the same way that supermarkets are usually in the best positions on the High Street, so must our sites be most carefully selected. With canopy, extra _and a console postpayment system is costly. lf this capital, together with the reduced profit margin which the dealer if he reduces the retail price, are to be offset, the site must be selected to command a high throughput. Those dealers who have made a success of self-service know that you only have one chance .. If the drives in first time and finds the equipment 1s sunple to use he will call again. Signalisation and signing are therefore of I?ararnount importance and 1 know from expenence that many dealers do not u_nderstand. this I hasten to say that l am not recomrnendmg a proliferation of unnecessary advertisements and meaningless notices. There is still a lot of work to be done in this field, especially on the instructions on the pumps themselves, and we are working closely in conjunction with the Board of Trade to this end.

Finally, on the subject of post-payment self-service, a few words on layout. Whilst a large forecourt is not essential, it is certainly preferable. In order to avoid confusion and c<?ngestion, to maintain control, and to speed up the operat1011, a controlled traffic flow is most desirable.

We publish a selection of papers presented to students at the mid-week school held in May

This can best be achieved by clearly marked entrances and exits and by defining with the aid of white lines the exact position of each re-fuelling point. The most experi- enced operators tend to favour the use of blender pumps for self-service, hence the motorist can drive to any vacant pump and from it select whichever grade suits his requirement. In this way waiting time is reduced to the minimum and the possibility of queuing at any one particular pump is overcome. Pumps should be sufficiently well,-spaced to allow two re-fuelling positions at each one. It is a normal requirement that the console is so sited that the operator has a clear view of each vehicle on the forecourt. When an autoshop is provided, it must be laid out so that the customer enters the shop, makes any purchases he may wish, and walks out via the console operator. This requires very careful design study. Lubricating oil sales can take place either from the oil stands on the island, from vending machines, or at the console. Air and water can be provided either on the island or at a "service point" away from the island. This will depend on the space available and on the predicted customer flow.

Pre-payment Self-service

Now we turn to pre-payment self-service. As you know, the number of vehicles on the road in the United Kingdom increases annually. In 1967 it was 14 million and by 1980 it is estimated that it will be approximately 30 million. The consequent congestion on the roads has led more people to travel at night, and with more car owners and more leisure time, a greater number are out for weekend jaunts. However, service station proprietors are finding it very difficult to find staff prepared to work long hours; and with ever-rising labour charges, as well as S.E.T., they are having difficulty in providing 24 hour petrol service to motorists which is at the same time profitable to themselves. Hence the increasing interest in "After Hours Self-Service". The aim may be defined as providing a 24 hour petrol service, seven days a week, at selected sites where it would not otherwise be profitable to do so. These will normally be in towns and cities and on busy highways, but after hours self-service may well have an application in tourist areas governed by seasonal trade such as the Scottish Highlands.

Usually the station will provide a manned service by day and the pumps will be switched to "After Hours Self-Service" during the evening and on weekends. However, my Company are carrying out experiments with a wh?llY station. This is not thought to have a nationwide application, but rather to meet the requirements of special areas where there arc particular labour problems and other economic factors to be considered. ?f these is due to be opened next month at B1llencay 111 Essex. You may be interested in the sales through note-acceptors for the first three months at the first five in the country offering after hours self-service. Already 111 these early days the average monthly sales have reached a figure in excess of 2,000 gallons per unit. This demonstrates that motorists do use these machines and that they do fulfil a social need. There is no cash advantage _in from them since petrol is retailed at full pnce .. Basically there are two types of machine 111 machine and the note-acceptor. When which to use the following factors have to be considered. Firstly, the size of the purchase-the £1

equates to the average purchase of approximately 3-} gallons and provides a better return to the service station operator. However, the 5/- machine provides a satisfactory "get you home" service. Secondly, availability of currency. How many of you have two half-crowns in your pocket? 1 am sure you will all have plenty of £1 notes ! Finally, decimalisation. There are comparatively few 10/notes in circulation and these will be discontinued in 1971 with the introduction of decimal currency. Half crowns will disappear also and existing machines will have to be converted to take either the I 0 new penny piece (2/-) or the 50 new penny piece. The note acceptor is capable of conversion when currency is altered but it may be more costly than the coin operator.

The machine being used by the National Benzole Retail Division of Shell-Mex and BP is the Beck 5/- machine. The BP Retail Division are using the Wayne £1 note acceptor linked to a Wayne Blender specially modified for this purpose.

There are four fundamental requirements which any equipment must satisfy.

1. lt must be safe.

2. lt must be secure.

3. lt must be simple to use.

4. It must be reasonably priced.

This last point need not concern us to-day. Mr. Wicks will be talking more fully on the first three though there is one po!nt I would like to develop a little before handing over to htm. Almost the first lesson which we have learned was that if the installation was to be successful, the instructions had to be clear and concise. We believe that we have done this, though with further experience we may make alterations. The principles we have followed are:

(a) Clear identification of the pump by use of a globe.

(b) Overall instruction board.

(c) Instructions on note acceptor.

(d) Instructions on pump.

(e) Special instructions required by Local Authorities, e.g. fire precautions, etc.

W. K. WICKS. Shell Mex and BP Ltd.

As Mr._ French has just said, I am delighted to have the opportumty to talk to you to-day on the subject of selfservice, with particular reference to equipment and safety. Apart from the old shilling's worth on a hand operated pump way back in the 1930's, self-service as we know it to-day was developed in Sweden by the Co-operatives in the late 50's, and this subsequently spread to Denmark and other European Countries. They concentrated on a modern sophisticated post-payment system, much as we know it here in the U.K. The first site to open for selfservice in the U.K. was at Plymouth using Swedish equipment. A very close second was at Southampton where the first British equipment was used. Both the sites were postpayment and the equipment used will be described a little later. Pre-Payment Self-Service Systems followed postpayment as a natural development. Australia led the way

in this respect, but the major development was in Germany with the M unztank operation in 1964. According to our latest information there are more than 150 post-payment types of self-service sites operating in the U.K. currently, and there must be approaching 100 installations of prepayment either coin or note operated sites also operational. In addition there are many sites approved for unattended self-service.

Systems Post-Payment

We are all familier with this system where the customer serves himself then visits the kiosk or control point to pay for his purchase. This equipment necessitates the employment of at least one person on the premises to control the pumps and to accept the payment, and is often referred to as attended self-service. This was the system introduced down at Plymouth _using Swedish equipment. At least five manufacturers in the U.K. are currently producing post-payment equipment and I will talk about these later.

Pre-Payment

As the i!nplies, the customer pays for his spirit before serving himself and by far the vast majority of systems are operated by the insertion of coins or bank notes, either into the pump or into control cabinets or consoles remote from the pump. One system was developed whereby the pump could be pre-set remotely through a cash register type of console but I have not seen this used in practice. The coin or bank note operated systems are the ones installed on the unattended sites, but you will gather that had the third system been developed to any great degree, we could have had an attended prepayment system. I understand that there are one or two sites operating with normal pre-set pumps as self-service. On these sites an attendant carrying a satchel patrols the forecourt taking the customer's cash and pre-setting the pump, then switching on for a customer to serve himself.

Equipment

As mentioned earlier, there are at least five pump companies manufacturing self-service equipment in the U. K. aI?d very broadly these can be split into two groups. F1rstly there are the electro-mechanical systems being produced by two companies. Basically this system consists of pulse generators, mounted on the money and volume shafts of the computer head in the pump, which send electrical impulses into control gear mounted in a console unit at the control point or kiosk. The pulses are counted electrically and are computed to provide readouts of both the cash and quantity. The controller is able to converse through an audio intercom system with the customers. This sometimes gives rise to difficulty because the intercom have to be intrinsically safe and so the power supply 1s very small. It is therefore difficult to obtain sound transmission which is higher than general noise level on the forecourt. When the customer has signalled his presence to the operator, he or she releases the pump for customer use. The operator is able at any time to switch ?If the supply of energy to any pump. Additionally, there is a master switch on the console which isolates all pumps. One manufacturer in the U.K. has developed a completely electronic system. In this case again pulse generators are fitted to the appropriate shafts in the computer head, but at the kiosk or control point the impulses are fed into

memory store and thence to a ticket printer, which, when the pump is switched off, prints a ticket automatically, this being presented to the customer when he comes to pay.

Two-way communication is included in this system through press buttons and light systems, which are very simple to operate and to understand. The customer presses a button on the pump which lights an amber light on the pump and the console. When the operator releases the pump a green light shows on the pump and the customer helps himself. Again the operator has complete control of the pumps, being able to switch on or off individual pumps or to isolate all pumps at will.

Two further U.K. manufacturers have developed systems utilising electronic equipment produced by a firm of electronic specialists. Naturally there are similarities between these two systems, but basically again we have pulses being fed from pumps back to. a control point. In this case they are fed mto an electronic memory store, and here the system becomes more sophisticated and more complex than the others mentioned SC? f'.1r. Having the information into the memory store, 1t 1s then possible to operate this system either as post-payment with readouts, or as pre-payment either bank note or coin operated. Used as post-payment the information from the memory store can be transferred to a readout and held whilst following customer operation is taking p!ace. the information can be transferred onmediately onto the readout which follows the pump computer as a slave.

When used as pre-payment either 5/- or £1 worth, the number of impulses corresponding to the. value inserted is recorded on a relay. When the pump 1s operated the pulses sent back from the pulse up to the number on the relays and the operation 1s terminated when the correct numbers have been dispensed. Audio intercoms are fitted on the post-payment systems but these suffer the same weakness as other similar arrangements.

A feature of the bank note operated and coin operated section is that the control cabinet has a system of ,air purging which overcomes the problems of flame p:oofing or making intrinsically safe. Some IC?cal find this acceptable and the control equipment 1s therefore allowed to be mounted adjacent to the petrol pump.

The Swedish equipment used on the first in this country is similar to two descnbed,_ 1s electro-mechanical with aud10 intercom, but ongmally this transferred price indications only.

Apart from the one equipment mentioned above, which could be used for either pre or post-payment, pre-payment equipment in the U.K. is mai_nly of t'_"o types. F1rstly, we have the coin operated variety operates by the insertion of two half crowns and dispenses only that quantity of fuel. With this system the _half crown can be recovered if the customer changes his mmd or does not have a second half crown which is valid, but when the second half crown has been accepted then the customer either takes his fuel or loses the cash. In this system the pump is pre-set to 5/- and the coins simply provide the electricity supply; the cut-off control being mechanical as with ordinary pre-set pumps. Coin accumulation using both florins and half crowns has been tried, but has not been developed to any great extent. The other pre-payment system that is familiar to us is the bank note operated equipment. The bank note validator is based upon the

American Dollar Changer, and is an anglicised, sophisticated version of the equipment which is used extensively in the U.S.A. This device scans a section of the bank note in great detail and is usually adjusted to reject about 5 % of valid notes. This means that very old, dirty and creased bank notes would be rejected.

The systems in operation are basically very simple. When a valid note has been accepted this simply supplies energy to the pump, which is mechanically pre-set, and cuts off automatically when the correct volume to the monetary value has been dispensed. In this respect it is similar to the coin operated 5/- version. In the bank note system a three minute timing device has been incorporated, the operation being completely cancelled at the end of this period.

Another system being developed and to be evaluated in the near future is a mechanical ticket printer built into the pump. Some form of intercom will be built into the system which will of course be post-payment. When the pump is freed by the operator the customer serves himself and at the end of the sale a ticket is issued automatically, which is presented to the operator for payment. This equipment will have power re-set which means that the customer will only have to remove the nozzle from the pump, serve himself, and return the nozzle to the pump, which is about as simple as the operation can be made.

A system is being developed using remote pumps with a readout on the nozzle end of the hose. In this system hose reels underground or suspended from canopies could be incorporated.

Yet another system under development will use blender pumps on a post-payment system during day time operation, and will switch to bank note or credit card unattended operation at other times.

These last two systems are not being developed in the U.K. and are very much in the development stage, so we need not concern ourselves with details at this time.

Nozzle

When self-service was tirst introduced into the U.K. it was suggested by some authorities that a nozzle should be produced which would ·not operate until it was placed in the fill pipe of the vehicle. It should be designed so that it would cut off automatically when the level of liquid rose up to the end of the nozzle, and should cut off in the event of blow back. It should also be impossible to grasp the trigger when taking it out of the pump.

Wayne Tank & Pump Company spent a great deal of time and money in developing a nozzle which would satisfy all the conditions called for. They built-in electronic sensing devices so that it sensed when a car was in front of the pump. There were other devices built into it, so that it would not operate until it was placed into an opening. It cut off as required in the event of blow back or fill up. This development cost that Company many of pounds, but it did not prevent a customer placmg a nozzle into a metal pipe similar to a car fill pipe and, what was worse, it could not be made reliable. The sensing devices were far too delicate for a piece of equipment which receives somewhat rough handling in quite norm.al operation. The significant point of course was that 1t could not be made reliable and thus would have created a hazard. The next development was carried out

by a continental manufacturer. In an attempt to satisfy some of the conditions, they produced a nozzle which had an external bar running underneath the spout, and which operated a moving fulcrum arrangement within the nozzle body. In theory this nozzle would not operate until it was placed into an opening, but the opening could be anything from a vehicle fill pipe to a section of chain link fence. In practice this nozzle proved to be most unreliable as the bar quickly became damaged due to being pressed against the sides of the vehicle fill pipe, and knocked against the pump when being replaced in its holder.

Far from being a safety feature this arrangement became an additional hazard as the customers failed to make the nozzle operate when in the fill pipe after a very short period of time in use, and therefore took it out and started fiddling with it. This often resulted in petrol being sprayed anywhere but into the proper place.

For these reasons, some of the authorities who had asked for this arrangement changed their requirement. The majority of pump manufacturers and certainly my own company strongly recommend that this nozzle is not used for self-service and generally a preference for the type of nozzle which has an inbuilt inertia device is stated. latter nozzles will not operate until the nozzle is pomted downwards below the horizontal, they cut-off automatically at very slow speeds in the event of blow back or fill up conditions, that is where the level of spirit rises above the end of the spout. We consider these nozzles to be eminently satisfactory and this would appear to be borne out by experience on the continent, particularly in Germany, where they have been used on the many thousands of coin operated machines installed on sites in that country.

In addition to the safety features built into these nozzles, in practice it has been found that customers serving themselves are more careful with their own vehicle than an attendant would be, and one rarely sees even the dribbles a.t the end of the running down a vehicle on self-service sites, whereas this often happens with attenadnts who tend to become somewhat careless.

Simplicity in operation or use

Ha_ving talked about the equipment used on self-service sites m the U.K. I would now like to turn to the three subjects which Mr. French said I would be developing, but I would like to reverse the order. First then let us consider simplicity of handling.

In the case of post-payment self-service equipment we have the. audio intercom whereby a customer may contact at any time the operator if he be in doubt or where any aspect of using the equipment is concerned. Additionally, the instructions on the pump have been designed after much consultation between the Board of Trade, the Equipment Manufacturers and the Operators (and by that I mean the Oil Companies who have developed self-service as a policy), but we are not suggesting that we have reached the ultimate in simplicity of use for post-payment selfservice systems. For instance, there are complications if a customer should require more than allowed by the limiting device, where either the override has to be operated or details of that sale cancelled and he should start again. There are further complications where blending pumps are used, as there are so many controls that some have to be placed on one side of the pump and the remainder on the

other side. In spite of this, however, operation of this type of equipment has been simplified to the extent that it is rare that a customer needs instruction after the first time of using.

Developments are proceeding as with the ticket printer pump mentioned earlier where we have reached about the ultimate in simplicity as the customer has nothing to do other than take a nozzle out of the pump, serve himself, replace the nozzle and take the automatically printed ticket to the kiosk for payment.

I think it would be fair at this point to give credit to our equipment manufacturers in the U.K. who have worked (very often in the face of opposition from authorities) to produce equipment which the public will find uncomplicated. Their developments have sometimes been sidetracked and complicated by marketing requirements of the oil companies and individual customers, but in spite of any difficulties, they have produced reliable equipment in most cases which has been sufficiently simple to use and self-service sites in the main are very popular and successful.

Security

When we talk of security we are referring mainly to those pre-payment systems particularly on an unattended basis. In the case of coin operated pumps, the pump casings are fitted with special locks and within the outer casing is a further coin box again fitted with a special lock.

Mechanical strength is built into this inner coin box, and we know of no case where insurance companies have asked for increased premiums where these equipments have been installed on sites.

Bank note operated equipment presents a different problem because cash values are proportionately higher. Here we have two slightly different problems, one being where the validator and control gear are sited remotely from the pump. The equipment manufacturer in this case has made the cabinet sufficiently strong to protect the delicate electronic gear of the note validator, and additionally to act as a safe for the money contained therein. The cabinet is constructed of heavy gauge steel plate, and designed in such a way that it is impossible to insert a lever between the side of the cabinet and the door, so that a grip can be obtained, thus forcing the door open. In addition to this, in most cases, the cabinet is built into either a block of masonry or the front of a building; but other than the prevention of the cabinet being hauled away, the building into masonry is not entirely necessary, due to construction of the cabinet. In the second case, we have the air purged cabinet which can be mounted on a post adjacent to the pump; here again the cabinet i.s in heavy gauge steel plate, and the door similarly constructed so that it is impossible to insert a le':'er 1?etween the cabinet and door edge with a view to forcmg 1t open. Again this cabinet can be built into a masonry block 1f so required, but of course, care would have to be exercised to ensure that the air passages are kept clear.

No doubt we could all think up many schemes whereby alarms are set off in the event of damage to the cabinets, but experience to date has shown that the construction of cabinets themselves, the siting of the pumps and t.he mtensity of illuminations on sites where this sort of equipment is installed, are sufficient deterrents to dissuade the

petty thief and vandal. Should there be an organised gang who are determined to break into this sort of equipment, then quite obviously they could succeed, but it would not be a simple matter for them, and it should be realised that in spite of all the sophisticated alar1:1s and up-todate designs of safes, many burglanes are still committed.

It must be safe

Safety is a topic which is uppermost in all our minds when we construct a filling station, whether it be attendant service or self-service, whether it be attended self-service, or unattended self-service. Safety is achieved by devices built into the equipment, and by codes of and licensing conditions desigi:ied to ensure that the is installed and operated m a safe manner. In the eqmpment we have pre-set devices which terminate delivery of product on either attendant operated pumps or on selfservice pumps. In the case of attendants, they. set the before the and this 1s able by the simple mampulat10n of a knob on the side of the pump. In the case of self-service, I have described this feature in the coin operated and the bank note operated pumps, where the pre-set is by the manufacturer and terminates mechanically the dehvery of products.

Limiting devices at quantities prescribed by the authorities are fitted to many pumps, thus ensuring that no more than the prescribed amount of product i:iay be dispensed in any one operation without some deliberate action being taken upon the pa!t ?f the pump operator. These limiting devices may be bmlt mto attendant operated or self-service equipment.

The safety nozzles incorporating the cut-?ff device which will prevent overspilling and mertia which will not allow products to flow until the nozzle is pointed below the horizontal. I described the nozzle developed for self-service earlier in my talk.

Finally, we have the principles of constructio_n. and licensing conditions which you gentlemen admm1ster. There has been lack of guidance on this subject in the past, but I shall be most disappointed if a new model code containing guidance on both attended and unattended selfservice is not available before the end of July. Indeed, when asked recently in the House of Commons for a date when this document would be available, the Home Office spokesman stated that it should be published in about three months from the end of March. In the meantime, advice can be obtained from the Home Office, and we must hope that any such advice that is sought and given will be based on the new model code. In the absence of any realistic guidance from the recognised authority, your Association produced some documents with which L am sure you are all familiar, and which have undoubtedly helped to fill the gap created by events overtaking legislation. When I spoke to a meeting of your Association at Huyton-with-Roby in April I made it quite clear that, whilst I could not agree with all the conditions contained in those documents, l appreciate the hard work and thought that went into the production of them, and expressed the view that the Industry and the Local Authorities should be grateful to those people who made the effort to produce them. Experience often shows that whilst intentions have been good, regulations framed to-day can quickly become obsolete.

The Nature of Petroleum Spirit and its Hazards

J. R. HUGHES. B.Sc., F.lnst.Pet. Chief Safety Engineer, British Petroleum Co. Ltd.

Nature of "Petroleum Spirit"

Petroleum-spirit, far from being a simple entity, consists of a large number of compounds. Chemically, therefore, it is neither feasible nor desirable to be able to make a complete analysis. Petroleum in its natural state, from which petroleum-spirit (gasoline) is derived, consists principally of a mixture of hydrocarbons of differing molecular weight and molecular structure which may be classed in three main groups (Table 1).

TABLE 1

Some lower boiling-point compounds in the three main groups of hydrocarbons present in crude petroleum

On analysis, a typical crude oil will be found to contain about 85 per cent wt. carbon and 13 per cent wt. hydrogen. Other elements, such as oxygen, nitrogen and sulphur may be combined with carbon and hydrogen, and small amounts of various metals, such as vanadium and nickel, may be present in the form of complex organo-metallic compounds.

Compound Formula Paraffins

Methane CH, Ethane CH 3 CH 3 Propane CH 3 CH 2CH 3

Butane CH 3 CH 2 CH2CHa

Pentane CH 3 (CH 2)aCHa

Naphthenes

Cyclopentane C5H10

Cyclohexane C 0H 12

Aromatics

Benzene Ca Ho

Toluene CaH5CHa

Normal state Gas Gas Gas Gas Liquid Liquid Liquid Liquid Liquid Liquid

Boiling point at normal atmospheric pressure op -259 -128 --44 31 97 121 176 176 232 291 98

oc -162.0 -89.0 --42.2 -0.6 36.1 49.4 80.0 80.0 111.1 143.9

I

l J.,•. I Fig. 1

t1Toppcd11

!n the secondary stage, the "topped" crude from the distillation is heated in a pipe still furnace and discharged into the main fractionating column at substantially atmospheric pressure. In this column, which is provided with a number of fractionating trays, separation occurs into different fractions or "cuts" according to their boiling ranges.

The fraction boiling between about 80° and l40°C (176° and 284°F) is a heavy gasoline suitable as a blending component for motor gasoline and for upgrading by catalytic reforming operations. The next fraction is naphtha, boiling between about 140° and 180°C (284° and 356°F), used partly in the manufacture of white spirits but more often as a feedstock for up-grading gasoline by catalytic reforming. Kerosine is within the approximate boiling range 180° to 250°C (356° to 482°F). The raw kerosine fraction is further refined by solvent extraction

to improve its lamp burning characteristics. Gas oil is taken off in the fractions boiling between about 250° and 340°C (482° and 644°F). The atmospheric residue which remains may represent about 50 per cent by volume of the crude oil charge. It is often used directly as a major component of heavy fuel oil, but it may also be processed further in a third stage of distillation carried out under vacuum. This final stage may be operated either to produce a heavy gas oil and a range of raw lubricating-oil cI.istillates (often paraffin waxes) or to give a smgle broad waxy disttllate or long-range heavy gas oil used as feedstock for catalytic cracking. The final vacuum residue may either be used as a component of heavy fuel oil or as base material to give a bitumen or road asphalt. products are usually not in the desired proportions or of adequate quality to satisfy the req1;urements of the market and they may, therefore, be subjected to further various refining processes. Some of (such as thermal and catalytic cracking) change the botlmg. range of .the products so as to yield, for example, more hght fractions at the expense of heavy fractions. Other processes, such as catayltic reforming, alter the molecular a given boiling-range product so as to .make more suitable for its end use, say, as motor while others such as hydrofining and autofining aim to remove or reduce the content of unwanted sulphur compounds.

Crude oil can therefore be made to yield, by separation, by conversion and by refining processes, a very wide range of products. Some of these are finding a new importance feedstocks for the rapidly developing petrochemical mdustry. Unfortunately, there are no universally accepted definitions of petroleum products but "A Glossary of Terms" published by the Institute of Petroleum, provides a useful reference for the interpretation of terms m common use.

The term "petroleum-spirit" is rarely used in the petroleum industry. It is defined in Section 23 of the Petroleum (Consolidation) Act, 1928, as "such petroleum as when treated in the manner set forth in Part II of the Second Schedule to this Act gives off an inflammable vapour at a temperature of less than 73°F (22.8°C)." In other words, it is "such petroleum which has a flash-point of less than 73°F, since "flash-point" is the temperature to which the petroleum must be heated to give off sufficient vapour to form a mixture with air that can be ignited momentarily by a flame".

The arbitrary nature of this definition is apparent when one considers the historical basis for choosing 73°F. In early days of oil-refining, when kerosine replaced coza oil or rapeseed oil for lighting, the flash-point test was used to distinguish between safe and unsafe oils. The steps. which Jed to the determination of the division point provide an interesting example of the origin of some of our traditional methods and specification limits. The Petroleum Act of 1862 stated: "petroleum for the purpose of this Act shall be any substance that gives off an inflammable vapour at Jess than 100 degrees of Fahrenheit's thermometer". No test apparatus was described, however, and the Act remained practically inoperative. In 1869 a Act was passed which a flash-pomt testmg apparatus designed by Sir Frederick A?el. It was soon found, however, that the results from this apparatus were not sufficiently repeatable and that

considerable skill was required for its use. In 1875, therefore, the Government asked Sir Frederick Abel to redesign the test equipment and make it suitable for use by "persons who have had comparatively little experience in conducting delicate experiments" He was also asked to say whether the then existing limit of 100°F (37.8°C) afforded adequate protection to the public. He reported that the limit 100°F by the old apparatus did afford sufficient protection, and he also redesigned the apparatus which is the presentday Abel closed flash-point tester. From extensive experiments he determined that the new apparatus gave results which were, on average, 27°F (15°C) lower than the results obtained with the old apparatus, and he therefore recommended that the Act should be revised to set a limit of 73°F (22.8°C); this was done in 1879. The temperature and the apparatus have remained unchanged to the present day for defining "petroleum spirit".

Sir Frederick Abel could scarcely have realised the tremendous implications of his recommendations. The international character of the petroleum industry makes it desirable that there should be a universally agreed definition for flammable liquids generally. The United States of America, France, Germany and the United Kingdom all have different classifications for flammable (synonymous with "inflammable") liquids, but there are indications in Europe at least, of moves towards an agreement for a' common classification. Such an agreement is "The European Agreement concerning Intert?-ational Carriage of Dangerous Goods by Road (abbreviated to ADR) to which the United Kingdom is a signatory. Under this Agreement, dangerous substances !isted under several classes, but as far as are concerned only the following categories of dangerous substances" are relevant:

(i) Liquefied petroleum gases, which come within Class Id of the Class Illa of the classification which include-

(a) "Liquids not miscible with water which have a flash-point below 21°C (69.8°F), e.g. .Petroleum volatile products from the distillation of petroieum and other crude oils, coal, legnite, shale, wood and peat tars;

(b) "Liquids not miscible with water which have a flash-point between 21°C (6?.8°F) ar:id 5.5°C (131 inclusive, e.g. petroleum oils (for or engines), heavy benzols, white spmt (turpentme substitute), solvent naphtha;

(c) "Liquids not miscible with 0 wluch have. a flash-point above 55°C (131 F) exceedmg but including 100°C (212°F), e:g. ce.rtam. tars a.nd · their distillation products, heatmg oils, diesel oils, and certain gas oils".

The ADR Agreement is not in final form but the Office Advisory Committee on Dangerous .111 advising the Home Secretary on the extent to which legislation is necessary concerning dangerous substances is naturally paying due regard to the ADR Agreement since it is a party to the Agreement.

ln a paper to Administrators of Petroleum Acts, it is perhaps excusable to have emphasized legal distinctions, but to revert to the physical nature of petroleum-spirit and for a better understanding of the hazards in handling and storing petroleum-spirit, we should consider now the properties of vapour pressure volatility and flammability.

Vapour Pressure and Reid Vapour Pressure

When a liquid evaporates, molecules leave the liquid and enter the space above it. If the liquid evaporates in a closed container, the number of molecules in the space above the liquid will eventually reach a maximum at a given temperature. The pressure exerted on the container wall is the sum of the pressure of the air and vapour molecules, and the pressure exerted by the vapour is called the vapour pressure of the liquid at that temperature. Further evaporation of the liquid is possible only by reducing the pressure in the vapour space (by withdrawal of vapour) or by an increase of temperature. Boiling of a liquid is characterized by a rapid and continuous evolution of vapour and implies either that the liquid is open to the atmosphere or that the vapour is being continuously withdrawn froid the container. A liquid boils when its vapour pressure equals that of the gas in contact with it.

The determination of vapour pressure is usually carried out under an arbitrarily selected set of conditions in an apparatus which is, in effect, a closed container where the ratio of liquid sample volume to air volume is 1 : 4 and where the temperature is accurately maintained at 100°F (37.8°C). The vapour pressure thus determined is known as the "Reid vapour pressure" (R.V.P.) and is recorded in pounds (force) per square inch absolute, but referred to simply in pounds. The test method emphasizes the need for great care when taking samples of liquid and when carrying out the test, to prevent loss of the more volatile components. Broad indications of R. V.P's for various petroleum liquids are given in Table 2.

TABLE 2

Reid Vapour Pressures of some Petroleum Liquids

R.V.P.

Petroleum Liquid lbf/in2a kgf/cm•a

Propane 190 13.36

Butane .. 52 3.65

*Crude oil (as usually shipped) I to 12 0.07 to 0.84

Motor gasoline 6 to 12 0.42 to 0.84

Aviation gasoline St to 7 0.36to0.49

Catalytic reformate 4 and above 0. 28 and above

Aviation turbine gasoline 2 to 3 0.14 to 0.21

Special boiling-point spirits and cerI to 4 0.07 to 0.28 tain light distillate feedstocks

Kerosine, white spirit, tractor vaporizing oil · · 0.05 to 0.5 0.0035 to 0.035

Gas oil, diesel oil, heavy fuel oils below 0.1 below 0.007

*There can be considerable variation in the R.V.P. of crude oil as found.

Volatility and Vapour Pressure

The term "volatility" is used to denote the tendency of a liquid to vaporise. There is no clear-cut distinction be!ween liquids of high, medium or low volatility, these general terms expressing the relative tendency of liquids to produce vapour, but as a rough index of 100

volatility the following Reid vapour pressure ranges are tentatively suggested:

Reid Vapour Pressure

Liquids of low less than 0.05 lb. volatility

Liquids of medium from 0.05 to 3. O lb. volatility

Liquids of high volatility above 3 lb.

Flammability and Flammable Limits

Example

Gas oil, diesel oil, fuel oils

Kcrosine, white spirit, aviation turbine gasoline

Motor gasoline, liquefied petroleum gases, most crude oils

Flammability d7n?tes the tendency of a substance to burn Although it is usual and convenient to speak of materials as in fact it is the vapour given off by the material that burns. There are two limits of flammability! a .lower and an upper, for each combustible vapour m air. The upper limit is the maximum concentrll:tion of c?mbustible vapour in air for combustion. !vf1xtures wh_1ch are. than the upper limit will burn m contact with air, as mixtures containing less than the upper hm1t are formed in the zone where the gases mingle with air.

The ?or_ice!1tration range lying between the lower and upper 1.s ?alled the flammable (or explosive) range; the l.1m.1t is commonly abbreviated to L.E.L. (lower hm1t) and the upper to U.E.L. (upper explosive 1m1t.

TABLE 3

1'.la'?lmabl.e limits in air of some hydrocarbon compounds and petroleum hqu1ds (mixtures of hydrocarbon compounds) (under ambient conditions)

Flammable limits Compound per cent (vol./vol.)

Lower Upper

Methane .. (gas) (CH4) 5.3 14.0 Ethane (gas) (C2H 6) 3.0 12.5 Propane .. .. (gas) (CaH8) 2.2 9.5 Butane .. .. (gas) {C4H10) 1.9 8.5 Pentane (liquid) (C6H 12) 1. 5 7.8 Hexane (liquid) (CsH14) 1.2 7.5 Heptane .. (liquid) {C7H1s) 1.2 6.7

Some co mmon petroleum liquids (mixtures of compounds):

Gasoline 1.4 7.6

Naphtha 0.8 5.0 Kerosine 0.7 5.0

There will be slight vari'at' · h 1 d" h ions m t ese 1m1ts accor mg to t e grade of the 1· 1 hth par 1cu ar gasoline kerosme or up ' ,

Safety in Handling and Storage of Petroleum Spirit

A of flammable limits is of considerable prac ica 1mpor.tance in the safe handling and storage of ltqmds. For example it will be seen from Fig_ure 2. that at normal temperatures in the Umted the vapour condition within a fixed roof tank contammg motor gasoline will be m an over-rich

state that is it contains too much vapour to burn, but this condition will change if air is introduced into the tank as when the gasoline is pumped out and displaced by air admitted through the roof vents. There will, for a short time, be a small zone inside the tank near the vents which will contain just the right proportion of vapour and air to be within the flammable (or explosive) range. Likewise, when more gasoline is pumped into a tank that has an over-rich vapour mixture, rich vapour will escape from the roof vents and become di! uted with air to form a flammable mixture outside the tank.

The extent of the flammable mixture zone is very limited and in the case of bulk storage tanks the concentration of flammable vapour at ground level would be too small to detect. Flammable vapour concentrations have been taken in the vicinity of the open dome hatches when filling road and rail tank cars with products of different volatility. It was found that at loading rates of up to 250 U.K. gal./hour into compartments having lOin. hatch openings, the concentration of vapour falls away rapidly within 2ft. of the hatch opening, even on a calm day. No flammable mixture concentration of vapour/air was detectable beyond a 3ft. radius of the hatch opening even with the most volatile product chosen for the test, normal pentane. The vapour concentration from motor gasoline was, naturally, less.

Flammable concentrations of vapour in air are possible, of course, within fixed roof tanks, as explained earlier, but this is an innocuous condition in the absence of any ignition source. A review of the comparatively few incidents of fire and explosion ll'ithin fixed roof tanks and road and rail vehicles indicates that a static electrical discharge has been the most usual ignition source. Our knowledge of the conditions which give rise to static discharges during the handling of petroleum liquids is more complete than it was a few years ago and operational practices, such as the of pumping rates, use of anti-static additive, electrical bonding of fill pipes to tank cars, and avoidance of tank gauging operations during periods of electrical storms, all contribute to a higher standard of safety.

Some of you will be familiar with the very large tank storages for crude oil usually located in remote locations at ocean terminals. Floating-roof tanks are used for large bulk storage and here there is no ullage space between the liquid and the roof, since the roof floats on the hqu1d. This arrangement provides the dual safety advantages of eliminating the vapour space above the liquid and preventing the accumulation of static charges on the liquid as the floating roof, which is earthed, provides an immediate path of separated charges to earth. Jn this C<;mnec:tion, it should be pointed out, however, that crude 01! unhke refined gasolines, is a relatively good conductor of and separated electric charges re-combine so readily that a negligible accumulation of total charge takes place. In the past, there have been fires at the peripheral seals of floating-roof tanks during periods of lightning but such incidents are now prevented by the prov1s1on of stainless steel conducting shunts across the fabric seal between the roof and the shell of the tank. During electrical storm, the floating roof of the tank sometimes acquired an induced electrical charge which discharged to the shell by way of imperfect contacts in the pantagraph hanger mechanism which held the sealing shoe against the shell of the tank. When there was a flammable

mixture in the seal space, ignition occurred at the hanger mechanism, but the provision of stainless steel shunts has now eliminated this risk. New types of seals have also been developed which, by avoiding or limiting the vapour space in the seal area, give enhanced safety.

In the handling of petroleum liquids, it would be foolish to deny the possibility of some escape of liquid whether it be at a refinery, marketing installation, depot or filling station, so long as there is some human participation in its handling procedure. My own experience, after many years in the petroleum industry, has shown that the most prevalent cause of accidents has been human error and I am constantly engaged with managements, training and safety officers in evolving safe systems of work which emphasize instruction and thorough training of operatives.

The Testing of New and Existing Petroleum Spirit Storage Tanks

J. BEER, M.1.W.M.A. Chief Inspector of Weights and Measures City of Worcester

In my talk, I propose to deal mainly with the testing of new tanks and then to point out such deviations as to make such requirements and procedures applicable to the testing of existing tanks.

I do not set myself up as an expert who knows all there is to know about the testing of petroleum tanks, but rather as a practising Local Authority Petroleum Officer who perhaps by nature is of a mechanical and an enquiring frame of mind, and who has accordingly given a little more than usual thought and research to the matter of tank testing.

Why did l delve into this matter ? Let me ask you what procedure do you adopt in tank testing-how do you test storage tanks to ascertain their soundness ?-like most of us I suppose a pressure test-and what margin do you allow for a drop in pressure, and it is no good to saythat is if you do not adopt the procedure I am going to advocate in a few minutes-that you do not make any

allowances-I used to, but 1 was not really satisfied with this procedure and that is what caused me to make the change.

After the change it always annoyed me when a fitter after there has been a small drop in pressure in a tank test with which he has been concerned, to say "Oh that should be alright, I expect you will allow me a quarter of a pound, they always do in so and so".

1 experienced this remark in one particular instance where, after correcting for temperature and barometer there had been a drop of one eighth of a pound. As it was a Saturday I suggested that nothing would be lost if we left the test on over the weekend, and if everything was in order the pressure would revert back to the original knowing of course that as there was a leakage there would be a more noticeable drop over the weekend. 'The site was at the bottom of a small hill from each direction and over the weekend, due to violent thunderstorms the excavations half. filled with. water. This found our leak for us and 1t was m the weldmg of a seam. It is true that it was only a pin hole and may not happen frequently but I think it is apparent that such small leakages could get through and could create unnecessary hazards.

I have gone to some lengths to make this point because I feel we should approach the matter of tank testing with a little more prec1s10n. I feel we should have more of a laboratory approach rather than allowing some small arbitrary figure of a quarter or half a pound for possible errors.

In other words, we should make the necessary corrections but should make no allowances.

It is really about such corrections and simple apparatus for applying them that I want mainly to talk.

I do not propose to deal in my initial remarks with special tests on special tanks but rather with the everyday gas, be it air or nitrogen, testing of ordinary 500-5,000 gallon underground tanks.

Basically all we have to do is to apply a pressure generally IO lb./sq: in. which i.s regist.ere? on a pressure gauge, and if there is no drop m the md1cated pressure after a period, usually twenty-four hours, the tank is passed as sound.

How delightfully easy it would be if it was as simple as that. But I am afraid this is not so.

You see, as in our schooldays, we are still troubled with Boyles and Dalton or Charles Laws.

I am sure it is not necessary for me to go into these in detail, always provided that I was able, but you will remember that in:

Boyles Lall' the volume of a given mass of gas at constant temperature is inversely proportionate to its pressure.

In other words, PV = P1V1.

In Dalton or Charles Law the volume of a given mass of gas at constant pressure is proportionate to its temperature.

I v v n other words, = ____!. T T1

No b . . PV P 1 V1 w corn mmg both Laws = T Ti

Where P = initial pressure

V = initial volume

T = initial temperature

P 1 = final pressure

Vi = final volume

Ti = final temperature

(The temperatures and pressures being stated as absolute)

As in the case of a tank we may have under test the volume is a constant then we have ' P P1 -= - or P x T1 = T x Pi· T T 1

What, therefore, I suggest we must do is to take both the pressure and temperature of the gas in our tank accurately and in absolute figures-and it is here that l may run into some lack of agreement.

.But let me get one thing out of the way. l think you will agree that a drop in temperature will cause a drop in pressure, and vice versa, but how much. I will explain the mathematics a little later but would ask you here to accept a figure of .09 lbs. or 1/11 lb. for each 1° Centigrade variation and as you will be aware such variation can be directly ascertained by an ordinary mercury thermometer, absolute zero being 273° C. below zero, usually marked on centigrade thermometers or the melting point of ice.

The other point which usually presents some argument is on the question of absolute pressure.

Now absolute zero pressure is a perfect vacuum and is m fact the height of the barometer below its level at the time of reading. Unfortunately we have no fixed point as with the thermometer from which to start as the ordinary, or Bourden tube pressure gauge is simply a comparitor of the pressure in the vessel which is being measured and the. pressure of the gas-in our case the atmosphere-in which the whole thing is situated.

To state some figures the height of the standard mercury barometer is 30 inches, which represents a pressure of 14.7 lbs./sq. in.

If, therefore, atmospheric pressure varies between the start and finish of a tank test, our comparitor-the gauge -will be affected. In other words, we must make a correction for barometric variations.

Nothing can convince like a practical demonstration and I have therefore brought along a little bit of homemade apparatus and here I should say "with apologies to Mr. Heath Robinson".

First of all to demonstrate a temperature fluctuation.

Here we have a small airtight container connected to a pressure gauge into which we put a pressure and then will vary the temperature.

Now to demonstrate fluctuations of barometric pressure.

Here we .have a small container with gauge attached. both of which are in an outer container to which also a gauge can be attached.

A yressure can be put in the inner container (from the outside) representing a tank under test, around which the pressure can be varied in the outer container, representing atmospheric pressure.

If now I pressurise the inner container with a certain mass of gas as there is no leakage will remain a constant, and without any outside influence other than

changing the outside pressure, the inner gauge moves down or up according to whether I increase or decrease the outside pressure; this, I think, clearly demonstrates that barometric variations affect the indicated pressure of a tank under test.

Having, I hope, convinced you that variation of temperature and barometer do affect the issue, it now remains for me to show whether the variations which are experienced in practice are significant, and I think I will also be able to do this.

You will remember at the start of my talk I gave a personal experience of one eighth of a pound drop ting a leakage which was subsequently found, provmg, I think, that a variation as small as that is significant.

Now we can revert back to our formula PT1 = P 1 T and Assume we start with a pressure of 10 lb./sq. in. which rounding off our 14.7 to 15 is 25 lb./sq. in.abs. That our initial temperature is 12° C. or 285° C. abs. and there is an increase to 17° C. or 290° C. abs. We have 25 x 290 = 285 x P 1 p 25 x 290 1 285 7250 285 = 25.44 for 5u C. rise which in round figures is .09 or l / 11 lb. for I" C. variation, which is quite significant, becaus;: is not at all uncommon to get temperature vanat10ns of 5° C. and more. do not need to use formula to show significance of barometric variations.

As mentioned previously, the height of the standard mercury barometer is 30 inches and represents a pressure of 14.7 lb./sq. in. Converting one to the other and again rounding off 14.7 to 15 lb./sq. in. then two inches of mercury = I lb./sq. in. In other words, a change of barometer of two inches makes a variation on the gauge of one pound, one inch of half a pound, half an inch of a_ quarter of a pound, and proportionately. Such variat10ns are bound to be significant as in time of meteorological deep depression variations of up to one inch in twenty-four hours are not infrequently experienced and with a large temperature change as well, I have now a correction of as little as one pound ! ! !

This I think you will agree proves the necessity for making such corrections.

Now for the apparatus and procedure to do the job.

We will assume we have arrived at that part of the progress of the installation when the tank is to be tested.

I suggest it should be tested when in position.

I suggest a definite drill so that members of our own staff and the pump and tank fitters know what exactly is needed and confidence is set up on both sides.

I suggest also we should provide ourselves with a couple of accurate and reliable gauges of 15 lb./sq. in. capacity together with a portable barometer to ascertain pressures. A I 5 lb./sq. in. gauge seems to be about the most suitable size because it is able to withstand the initial surge when the valve is opened to a tank under 10 lb./sq. in. pressure which a JO lb./sq. in. gauge is not so able to do. The gauge

should have about a 6in. or 9in. diameter dial so that the graduations can be in relatively small increments.

We should have a supply of what I call temperature tubes which may be borrowed by fitters, etc., when preparing tanks for test, together with other sundry apparatus the need for which will become apparent to you as you do your work.

Having received information that a tank is to be tested a temperature tube is made available before the fitter applies the pressure. He will quickly become accustomed to this drill.

If such pressure is applied to the tank by air pump there will be a heating up. If by air or nitrogen released from a pressure bottle there will be a cooling. I wou'd therefore suggest that three or four hours must elapse between the application of the pressure and the start of the test in order that the temperature may stabilise.

As l feel it is always better to try and reduce the possibility of change of temperature as much as possible, whenever I can I always endeavour to start and finish a test as early in the morning as can be. The reason for this being that night time temperatures are more likely to be similar to each other than those of daytime when the effects of sun and cloud can create quite large variations. It is also better to cover the tanks wherever possible.

Having personally taken the temperature, barometer and tank pressure, of which careful note is made and ascertained by a soap and water test that the control valve is not leaking, the gauge should be r.!moved and the fitting scaled to prevent tampering.

J\fter the lapse of twenty-four hours the readings are agam taken, the corrections applied, and ifthere is no drop the tank passed as sound.

If there has been a drop in the corrected pressure the tank will be leaking and it will be necessary for this to be rectified, usually ?Y the fitter, and the whole procedure gone through agam.

On t.he second .visit l like to ascertain and apply the correct10ns, workmg out what the pressure should be shown on the gauge before turnincr on the control valve as this seems to be far more effective than to afterwards work out something that will justify a variation in pressure.

Having done all this l am of the opinion that NO allowance should be made. The tank is either SOUND or NOT SOUND.

There may be a very slight "blow" from one or two of the manhole holding down bolts or in the gasket which in themseI:--es would not be very serious, but no-one can say what this represents and until a tank is proved to be absolutely sound any drop in pressure could represent a small blow hole in a seam weld.

I think 1 have covered the various points L wished to make regarding the testing of new tanks, but before passing on, there is one particular thought 1 would like to leave with you.

You will remember my reference to a drop of one eighth of a pound representing a small leakage. Now let's assume that we belong to the school of thought that makes no corrections for temperature and barometer.

If there had been variations which made the pressure rise one eighth of a pound or more, that leakage would have been entirely masked and of course quite a large leakage

could be masked if variations are large, maybe representing an increase of up to half, three quarters or even one pound, and far more than that if we are also prepared to allow half or three quarters of a pound as well.

Cases also arise where there should be an increase in pressure of "so much" but in fact the has remained the same or has mcreased, but a s1gmficantly less amount, in which case there would of course be a leakage.

On the other hand, the testing of tanks takes up valuable time and fitters' wages, so that if the variations cause a drop in pressure then it is only fair that we should acknowledge this also.

Before it was my practice to make the corrections to which I have referred, there were many occasions where there were somewhat unexplained variations about which I was not entirely happy. Since, however, adopting the correction procedure some 16 or 17 years ago, I get a personal satisfaction that I am now passing only really sound tanks and at the same time being fair to the other side. You know it is quite a sobering thought that if we make an allowance instead of applying corrections we may be passing a leaking tank as being sound.

I think it is true to say, if we have said a tank is leaking, then one or more leaks have always been found.

Pipe lines

Although the quantities which could get away through a leaking pipeline would most likely be nothing like as serious as from a leaking tank, there still would be little point in assuring the soundness of one without the other.

Owing to the small mass of gas in pipelines as compared with a tank, the same problems do not arise although the question of temperature can give considerable variation if we use the two hour duration test.

As I see it there are two methods, both using a pressure of ten or more pounds per square inch, the one where the pressure must hold for two hours and the other a soap and water test. Personally, I prefer the latter. It is quicker, saves a second visit or hanging about for two hours and certainly picks out the smallest of leaks.

All that is required after the pressure has been applied is to go over all joints, elbows, sockets and connectors using a good paint brush and a supply of water to which detergent has been added, using a looking glass to see underneath or at the back of pipework. Any leakage of course will be shown up by soap bubbles.

I always insist on testing vent lines.

Existing tanks

As you will perhaps know, it is suggested that these should be tested after 20, 25, 30 years and thereafter by two yearly intervals, these periods being specified as 25-30 years is the anticipated life of a tank.

Two methods are open to us.

I. A pressure test of from 5-10 lbs./sq. in. using nitrogen or an inert gas (air must NOT be used as it could form an explosive mixture, particularly on release).

The tank must be bottomed and by this l mean that the last few gallons which cannot be removed

by the dispensing pump must be taken out through the dip pipe by a semi-rotary hand pump on top of a length of piping which goes right to the bottom of the tank. The pressure can be applied to tank and pipelines together after the top of the vent pipe and the petrol pump has been blanked off. The same principles as mentioned for testing new tanks should be employed.

If leakage is found then tank and lines would have to be tested separately.

2. An ullage test which is suggested by the Home Office. I do not propose in my initial remarks to go into the pros and cons of each type of test. The ullage test is carried out on the tank by disconnecting the lines and completely filling the tank, taking the dip at the start of the test and again after twenty-four hours.

The ullage is taken and not the dip reading as the former involves far less disturbance of the spirit level than does the latter.

Again this sounds most simple but believe me it is not quite so simple, as experience may have shown some of you.

Now for a few helpful hints on the ullage test.

(a) The spirit to top up should be delivered the day prior to the start of the test in order that the temperature may have time to stabilise. I do, however, suggest a reading should be taken and a rough check made in that first twenty-four hours in case there was a large leakage at the top of the tank which had not previously shown up because a tank is seldom completely filled.

(b) It is surprisingly difficult to take a. consistent reading, but I have found a most meth?d is to have a small brass rod graduated m 1/10 m. with a sand blasted surface and adjustable shoulders to rest on the top of the fill pipe.

(

c) The level of the spirit should be J:>elmy the bottom of the neck of the tank otherwise air or vapour will most likely be trapped at the ends and tively small variations will cause the most amazing differences m liquid level.

(d) Disconnect line.s, par.ticularly the vent lines, otherwise variat10ns will be set up.

(e) Finally, although an ullage test may be put on a tank the Jines must be tested by pressure and as they underground this must be a duration test.

There are of course other factors, 111:ethods of testing tanks and other types of tanks with which I have not had time to deal. I of course to the. soap and water and also the hydraulic method of testmg tanks, together with the testing of above storage tanks, and whilst l do not mtend to deal with them initially, l will be to do so should you ask about these things in quest10n time.

ln conclusion l hope I have been of some help and interest and if my talk has only made you start to think and go back to your own areas to further investigate this subject for yourselves, l shall have been more than amply repaid for any time and effort l have used in preparing my talk.

Gas Pressure Testing of Tanks

In this article C. L. Davids by means of an interesting mathematical exercise proves what to many must be an unlikely truth

When testing any vessel be it tank or pipe line, by air or gas pressure, the pressure will on the full scale reading of the gauge. This should m turn depend on the applied pressure.

Assume that the observable pressure drop, can be called the sensitivity of the test, is nP. Where n is fraction and P is the applied pressure. For example, with n = 1/50 and P = 10, the observable pressure drop would be 1/5 lb. If P is 100 then the lowest drop which could be observed would be 2 lbs.

The air or gas lost during a pressure test over. a time t hours is proportional to the area of the 111!1-es the velocity of the escaping gas. This velocity is m turn proportional to the square root of the pressure.

Therefore, we can say:

Air Lost = KAty'P

Where K is some constant, A is the area of the leak, t is time, and P is the pressure.

The pressure drop due to this loss of air or gas is proportional to:

Air Lost/Capacity.

Therefore Pressure Drop equals: KAty'P Capacity

BRANCH

East Midland

The Annual General Meeting of the Branch was held at the Guildhall, Lincoln, on Thursday, the 2nd May, 1968.

Present were the Chairman, Mr. E. T. Crowe, and 30 members; 14 apologies were received.

Members were welcomed in the morning by the Deputy Mayor of Lincoln, Alderman F. R. Eccleshare, on behalf of .the Mayor, Alderman S. A. Campbell, who was fulfillmg an engagement at Plymouth regarding H.M.S. Lincoln. He referred to the historical aspects of Lincoln and then paid tribute to the progress of the Branch. As officers, he said that it was not enough to deal with.current safeguards but to anticipate future trends and requirements and this was shown by the Conditions relatmg to self-service petrol stations recently issued by the He expressed his sincere thanks for the work bemg done by the Association which was of great benefit to local authorities. The Branch Chairman, Mr. E. T. Crowe, then thanked the Deputy Mayor for his welcome to the historical city of Lincoln where he said it was always a pleasure to meet. The Deputy Mayor then wished Mr. E. T,. Crowe a happy retirement from his office of Borough Engineer and Surveyor of Mansfield and left the meeting.

If this can just be detected it equals nP. Therefore:

nP = KAty'P Capacity KAt or n = Capacity

xy'P

This confirms facts which are very well known, i.e., that the sensitivity of the test or the likelihood of a given leak being detected depends on:

1. Size of the leak, i.e., A; the larger it is the more likely it will be detected.

2. Time of test, i.e., t; the longer the test, the better the chance of detecting a leak.

3. Inversely as capacity; larger tanks are less likely to show up a given leak.

But it is not so well known that it is inversely proportional to the square root of the pressure. The higher the pressure the less likely one is to detect a small leak. The pressure applied must be at least one and a half times the working pressure, but any further increase in pressure does not increase the sensitivity as long as this increase means that a gauge with a larger full scale deflection must be used.

MEETINGS

Minutes

The Minutes of the last Branch Meeting held at Scunthorpe on the 12th October, 1967 were confirmed. There were no matters arising from th; Minutes.

Membership

applications for ordinary membership and four apphcat10ns for associate membership were received and approved by the members.

Report of Branch Representative

Branch gave his report on the proceedmgs of the Council of the Association. Several memover the difficulty some local authorities had m obtammg places for their officers at Attincrham Park and it was suggested that a second course alleviate the position.

Report of Secretary/Treasurer

The Secretary gave his first report on the activities of the Branch since its formation. There were 51 members when the Branch formed and membership had increased to 75 and was still increasing. The presented balance sheet

indicated a good financial position mainly due to initial capitation fees. There had been some earlier confusion as to the payment of branch subscriptions, but the Branch Rules and Constitution had now clarified the position, and it was anticipated that a sound financial position could be maintained. The report was approved.

Election of Officers and Committee

The following were elected: Chairman: G. C. Cartwright, Nottingham City

Vice-Chairman: J. Bantoft, Derby C.B.C. Hon. Secretary/Treasurer: J. Birks, Chesterfield M.B.C.

Hon. Auditor: J. Bantoft, Derby C.B.C.

Committee Members: M. T. Lucas, Scunthorpe M.B.C. W. H. Matthews, Derby C.B.C. B. S. Pike, Market Harborough U.D.C. J. Staddon, Esso Petroleum Co. Ltd.

Branch Representative: J. Birks, Chesterfield M.B.C.

Installation of Chairman

Mr. G. C. Cartwright was installed as the new Branch Chairman by Mr. E. T. Crowe, who had occupied the office since the formation of the Branch two years ago.

Discussion on the Special Conditions of Self-Service at Retail Filling Stations recommended by the Association

An interesting discussion took place on the Special Conditions. Mr. Pike said that the 10/- minimum for prepayment petrol pumps was not realistic enough and would not necessarily deter vandals. He thought 5/- was more realistic. Mr. Cartwright said he had experienced no true acts of vandalism in his area on pre-payment petrol sites. Mr. Dale said that in his area there had been little cause for complaint from about 300 coin-operated paraffin pumps set at 2/-. He said that the Home Office had suggested a 4/- minimum which he thought was in anticipation of decimal currency. Mr. Pike thought that there was now some lack of uniformity and that there should be some guidance from the Association. Mr. Birks said that the Conditions were only recommended by the Association and that any petroleum officer could suggest his own minimum to his local authority if he wished to do so. Mr. Norris reminded members that in three years' time the 10/- note would disappear but thought that 4/-, representing less than one gallon, was an insignificant amount. On balance he thought that 10/- was right and could be replaced J:y 50 new Mr. Staddon said that petrol compames were playmg carefully at the moment. He said that he could see both sides of the argument and hesitated to express a firm opinion. Mr. Popplewell referred to the problem associated with some motor scooters which only had a tank capacity of about one gallon. It was then proposed by Mr. Pike and seconded by Mr. Crowe that Condition l of the Special Conditions for unattended Self-

Service at Retail Filling Stations should be reconsidered by the Association and that the I 0/- minimum should be reduced. This was carried.

Mr. Crowe referred to the suggested ringing fire alarm system and wondered exactly how it would operate. Mr. Norris said that he could see the value of an alarm bell at a self-service station having a repair bay and someone present who could give assistance, but cou!d see no value in having an alarm bell at a self-service stat10n where there was no assistance to be summoned. Mr. Bilbie thought that automatic dowsing devices might be used on self-service stations.

The business was then concluded and mem hers adjourned for lunch.

Address

At the afternoon session the Chairman introduced Mr. W. C. R. Dale, A.F.Inst.Pet., Principal Administrative Officer Licensing Department, Greater London Council, who an excellent talk to members entitled: "Current Petroleum Licensing Problems". Mr. Dale said that petroleum officers should be prepared to accept but only if it was proper and s'.1-fe to do so. _His talk covered a very wide field and provided members with much technical information to help them in their current everyday problems and the special problems now evolving from modern retail distribution methods. The range of subjects covered included the history of latched nozzles, the lay-out of self-service stations and their location, alarm systems and emergency procedures, remote pumping, standards of safety for electrical apparatus, plastic tanks, multi-storey car parks and the conveyance of petrol by road.

In opening the discussion, Mr. Lucas asked what exactly should a petroleum officer be for when examining a petrol road tanker. Mr. Dale said that Mr. B:er of Worcester had produced an excellent questionnaire for such examinations and related faults on road tankers he had found in spite of systematic inspections. Mr. Ainsworth asked about the procedure for installing underground plastic tanks and the danger of damage from impact. Mr. Dale said that a concrete was recommended for there could be an abrasive action between the tank and concrete by the tank walls moving under the pressure of va!ymg loads. He advised a one foot s_urround sott matenals such as but the oil compames had thelf own procedure. He said that a protection saddle should be fitted at the bottom of the fill-pipe to prevent damage to the tank_ bott?m by a falling dip-stick and that a fibre-glass tank :v1th thick walls was not necessarily stronger. Mr. Norns _asked about the possibility of latched nozzles when to the designed break-away pull of 60 lb., also pulling the hose away from the pump.

Mr. Dale said that successful tests had been made in the United States where 1t was found that the hose and pump could withstand a. pull of 180 lb. Mr. Sendall asked about the correct locat10n of petrol pumps from the pavement. Mr. Dale _did not any_ fixed distance and said that some gmdance might be denved from B.P. Research who had found that when a vehicle is re-fuelled a petrol cloud forms within two feet of the tank orifice and within four feet in the presence of a wind.

Mr. Cartwright said it was difficult to obtain a completely unobstructed view of petrol dispensing on selfservice stations and wondered what might be the best lay-out in order to achieve this. Mr. Dale said that a completely unobstructed view could only be achieved if the operator was situated 20 feet above the yumps but this was impracticable. Unforeseen obstruct10ns always occur on self-service stations and he thought that a good general observation of the station by the operator was. all that could be achieved, which was better than a wandenng forecourt attendant in many ways. Mr. Staddon thought that mirrors suitably placed might be useful but Mr. Dale said he had never insisted on the use of mirrors since they could be affected by snow and condensation. Mr. Bates wondered whether leaks on petrol tanks were caused by corrosion or a faulty weld. Mr. Dale said that experience had shown that leaks were <>enerally caused through corrosion and gave various saying that it w:;i.s impossible to generalise. Mr. Lucas asked whether 1t was better to test tanks by gas pressure or by ullage. Mr. Dale said that there was always an element of danger and uncertainty when using gas pressure and in some ways it was an unfair test. Atmospheric pressure and temperat1;1re should be taken into account if the test was to be earned out with any certainty. He recommended a short hydrostatic test and thought that ullage tests satisfactory since air and vapour in the vent pipes might effect the liquid level.

He said that leaking petrol tanks in London were obviously dangerous, and as a precaution anyone with tanks over ten years old were asked to keep records of sales and inform his department of any serious losses. Mr. Crowe asked what allowance could safely be made when a pressure test had been carried out, taking into account the effect of atmospheric pressure and Mr. Dale said that no allowance could be made and said that a fall oft lb./sq. in. represented a substantial leakage on a 5,000 gallon tank.

Mr. Ainsworth then proposed a vote of thanks to Mr. Dale for his most informative talk and members then had tea at the kind invitation of the Mayor of Lincoln.

South Eastern

The Annual General Meeting of the Branch was held at the Council Chambers, Bridge Street, Godalming, on Wednesday, 15th May, 1968.

Present

Mr. J. R. Domoney in the chair and 39 members.

Apologies

Apologies for absence were received from 14 members.

Minutes

The Minutes of the last meeting of the Branch held on the 21st February, 1968, at Godalming, having already been circulated, were confirmed and signed as a correct record.

Finance

The Treasurer reported a balance in the Branch General Account of 19/- and stated that a cheque was expected from the Association's Secretary to cover the Branch capitation fees.

Election of Officers and Committee

The following Officers having been duly proposed and seconded were elected to serve the Branch in the ensuing year:

Chairman: F. A. Smith, Worthing M.B.C. Vice-Chairman: J. W. Hewison, Havant and Waterloo U.D.C. Honorary Secretary: C. R. Peskett, Godalming M.B.C. Honorary Treasurer: J. E. Hay, Hambledon R.D.C.

Auditor: D. Taunton, Guildford M.B.C. Branch Committee: R. Martin, Brighton C.B.C. F. Barker, Esher U.D.C. T. Steel, Crawley U.D.C. E. Williams, Sevenoaks R.D.C. H. Robinson, Surrey Fire Brigade

Installation of Chairman

Mr. F. A. Smith took the chair of the meeting and thanked members for electing him to the office. He also thanked Mr. J. R. Domoney for his Chairmanship during the past year.

Demonstration

Mr.. F. A. Selboun:ie, the Regional Sales Manager of the Mmes Appliances Co. Ltd., was then introduced to the meetmg by the Chairman. Mr. Selbourne addressed members and the full range of instruments manufactured _by his Company, including Explosimeters. At the conclus10n of the talk and demonstration members posed a number of questions to Mr. Selbourne on various aspects of the equipment demonstrated and subsequently were able to handle and test the effectiveness of the range mstruments on display.

Chairman t_hanke? Mr. Selbourne for attending the meetmg for his det:;i.Iled and constructive explanations oft.he techmcal use of his Company's range of instruments, which had proved both interesting and helpful to all the members present.

Any Other Business

The_ reI?orted on a recent meeting of the Assoc1ah?n s Council held in Nottingham and informed the meetmg _that a newly formed Technical Committee was to look mto for Use in Emergencies and would also _lookmg _at the Association's recommended Codes, Cond1t10ns of Licence, etc., when the revised Home Office Model Code was received.

Mr. Hewiso_n reported on a further test on the OPW I AA :\utomatic. Latch-On Nozzle which had again proved 111 respect of the break-away feature; detatls of the test appeared in the July issue of the Bulletin.

'The Secretary gave preliminary details of a proposed v1s1t to the Streatham Vale plant of Messrs. Beck & Co. (Meters) Ltd., on Wednesday, 26th June, when it was hoped _members would have a full opportunity to examine and _discuss. the Company's Coin Operated Petrol Dispensmg Umts.

Through the Pipeline

by otto

WHY BE REMOTE ?

In a suction pump, the pump evacuates a chamber and then atmospheric pressure pushes in petrol or whatever is available to fill the void.

Let us assume that the atmospheric pressure today is 15 p.s.i.g. Then knowing that a one foot head of water weighs (or exerts a pressure of) 0.434 p.s.i., we can calculate that if our suction pump had created a perfect vacuum today's pressure would be capable of pushing water up 15 -:-- 0.434 feet or approximately 34! feet to fill the void. The water will achieve no greater height than this even if the vacuum stretches from here to the moon. We will not achieve this height tomorrow ifthe barometric pressure drops to 141- p.s.i.g.; our top limit will then be not much over 33 feet. However, anyone accustomed to pumping water knows that it is impossible to obtain a perfect vacuum with the standard suction pump and would therefore never attempt to suck water up more than about 20 feet.

Petrol is lighter than water. Its exact specific gravity varies with grade but a figure of 0.75 is about the right order. Thus with a perfect vacuum and an atmospheric pressure of 15 p.s.i.g. one might expect to produce a column of petrol 34-!-:-- 0.75 feet or approximately 53 feet high. In practice, however, there are complications with vapour boiling or flashing off and destroying the vacuum; petrol pump manufacturers who are experienced in the field recommend a maximum suction lift of 12 feet for petrol. Moreover, they suggest a maximum horizontal suck of 100 feet. All petrol pumps in current manufacture in this country will better these figures but the manufacturers are wise to lay down limits.

These restrictions apply, of course, only on the suction side of a pump. On the pressure (or discharge) side one can push petrol as far and as high as one wants if one is prepared to build a pump which is big enough and strong enough.

Many garage proprietors, nowadays, wish to keep their forecourts purely as sales areas and not have them cI1;1ttered "'.ith ut:iderground petrol tanks which will cerrequire fillmg and may require servicing from time to One way of doing this and beating the limitations which the use of suction pumps imposes, is to site the pumps and tanks in a position remote from the forecourt to feed the dispensers on the forecourt by pressure Imes the pu:i1ps. It is pertinent to add from the econon:uc standpomt that a dispenser without an integral pump is cheaper !O replace than a standard measuring pump when the time arrives for the periodic forecourt face-lift.

However, although the interests of economy may be served by this arrangement, safety most definitely is not. Firstly a pressure line with a hole will leak all the time it is under pressure (i.e. while the is working) a suction line can leak only when 1t 1s not under suction. Secondly the quantity lost from a pressure line through a hole of given size greatly exceeds that that would be lost from a suction line. Thirdly, a pump attendant should be able to recognize that a suction line is faulty from the performance of the pump whereas he would have no immediate indication of a pressure line leak. Lastly, if a dispenser connected to. a line is over while its remote pump 1s workmg petrol will be sprayed all over the forecourt; such a thing could never happen with the standard petrol pump.

However all is not lost because there are leak detector valves which will indicate a leak in pressure lines. What is more impact check valves can be fitted at the base of to stop outflow of petrol when a dispenser is demolished.

WHAT'S PRESSING'?

Most people are familiar with the check valve which is opened by pressure on its head and which closes when either this pressure is removed or a back pressure develops. We all have valves not unlike this in our veins.

There are some valves, however, which are arranged to open only when pressure is on their skirts. Examples of these are to be found m the 1:eg1;1Iator and by-pass valves of some petrol pumps. The skirt 1s attached to the bottom of the valve stem and when pressure. on one side of the skirt exceeds the on other side, a force is available which, unless restramed, will move the skirt and hence the valve via its stem.

The strength of avail3;ble force depends on two things, namely, the difference m between the two sides of the skirt and the area of the skirt to the pressure differential. Let us .assume that tl:ie skirt has an exposed are.a of square mcI:es; then, .1f the pressure differential 1s 20 p.s.1.g., the movmg force 1s 40 lbs.

Movement can be opposed by a sprin!f. lf, for example, the spring exerts a force of lbs., then m the .case qt.1oted the valve will not budge until the pressure d1fferent1al at its skirt exceeds 15 p.s.i.g. Use of this fact is made in the leak detector valves to be found on the pressure lines of some remote pumping installations.

Pressure built up in a line by the remote pump remains in the line after the pump has stopped provided that there is no leakage from the line and no drop in temperature.

So Jong as the line under resi?ual pressure, and the pressure differential ex1stmg at_ the of the leak valve is sufficient the valve will remain open. If there 1s leakage or contraction due to temperatu_re drop, pressure is Jost, the valve closes and further flow 1s prevented.

Because liquid is virtually incompressible loss of pressure would follow very minor loss or contraction of liquid. This would make the system far too sensitive. This snag is usually overcome by arranging a bleed hole through which.liquid can by-pass the closed l_eak valve to re-pressurize the line. When the lme 1s sufficiently repressurized the leak detector valve re-opens and all systems are "go" once more.

The bleed hole is made very small, usually sufficient to pass only about 3 gallo_ns per _hour. This that if _a quart is lost from the !me whrle the press_unzmg pump 1s switched off then it will take at least five :rnmutes to replace the quart when the pump is switched on. If the hole in the line is so big as to pass more than 3 _gallons J?er hour then it will never be possible to pressunze the !me and open the leak detector valve until the hole has been repaired. At the working pressure of the average remote pump installation at filling stations, 3 gallons per hour would pass through a hole having a diameter of only 0.013 inch.

Thus a hole smaller than 0.013 inch in the pressure line would be revealed when delay in discharge occurs at the dispenser after the remote pump had been switched on. The delay would get. longer as the size of the hole increases untJI no delivery at all would take place when the hole exceeds the critical diameter of about 0.013 inch. Quite a neat solution to a pressing problem !

On 30th May, 1968, Harrow Magistrates imposed total fines and costs of £35 and £7 7s. Od. respectively on Regent Transport Ltd. The company's tank wagon SLD 793 had been found on 29th January, 1968, to have all its six manlids open and a defective foot valve.

Just over a week later on 7th June, 1968, at Brentford Magistrates Court, Nafta (G.B.) Ltd. were dealt with more severely when total fines and costs respectively of £70 and £10 10s. Od. were imposed. The offences occurred on 2nd February, 1968. On that day the company's tank wagon HNM 330F did not carry a fire extinguisher (£20 fine) and had all five of its manlids open (£10 on each).

A similar fate befell Freerange Co. Ltd. at Stratford Magistrates Court on 25th July, 1968. The company had to pay £90 in fines and £5 5s. Od. in costs because its tank wagon SXC 556 had no fire extinguisher, was defectively wired and had unlocked draw-off taps, leaks in one drawoff pipe and tap, an uncovered vent and manlids which were not locked.

Four days later on 29th July, 1968, VIP Petroleum Ltd. suffered a much harsher punishment at Willesden Magistrates Court. The company was fined a total of£ 125 with costs of £15 15s. Od. The offences related to tank wagon FBA 408C which on lst April, 1968, had a large aperture in its fire shield (£50), no protection to its drawoff pipes (£25) and all five of its manlids unlocked (£10 on each).

PETROL INCORRECT OCTANE RATING

At Shrewsbury Magistrates' Court on 13th August, 1968, AM<;lCO (U.K.) Ltd. pleaded guilty to an offence under Sect10n 2(2) of the Merchandise Marks Act, 1887, as amended, and were fined £I O and ordered to pay £14 18s. Od. costs.

Legal Proceedings

TANK WAGONS-NO FIRE EXTINGUISHER, MANLIDS NOT SECURE, FAULTY CONSTRUCTION

Magistrates in London are continuing to heavy penalties for mfnngements of the Petroleum Spmt (Conveyance by Road) Regulations, 1957.

An oil company employee who smoked while driving a tank wagon was required at West H_am Magistrates Court on 13th June, 1968, to pay £15 with £2 costs-an expensive cigarette !

Operating companies have also suffered.

A complaint from a member of the public to the Weights and Department alleged that after driving about half a m!le beyond a petrol station where he had pur- chased 10-!. gallons ?f AMOCO Premium petrol (five star) his car engme suddenly started to pink and run very roughly. Mr. G. Balshaw then purchased three twogallon samples from the same flowmeter. One sample was by the Assistant Manager of the garage, one was submitted to a laboratory to evaluate the research octane number and the third retained at the Weights and Measures office.

The laboratory later reported that the research octane nu.mber of the sample submitted was 92. In order to verify this. result AMOCO (U.K.) Ltd. submitted the sample retamed by the garage to a further laboratory which reported the research octane number to be 92.1.

The explanation offered by AMOCO (U.K.) Ltd. was that either the delivery tanker had been loaded wrongly at the terminal or the driver had unloaded the wrong compartment into the underground storage tank.

ANNUAL GENERAL MEETING

Solihull-24th April, 1968

APPOINTMENTS

F. L. Birkett

T. N. Bond

S. J. Caen

S. A. Eade

R. H. Eveleigh

J. Gaskell

S. A. Gower

G. A. Hodgkinson

C. A. Howard-Luck

D. H. Jagger

H. Johnson

R. E. Platt ..

R. S. Relf

S. V. Robinson

J. Saunders W. D. Scott

P. West

BRANCH MEETINGS

East Midland 12th October, 1967, Scunthorpe 2nd May, 1968, Lincoln Northern (Teesside)

31st October, 1967, Middlesbrough 29th April, 1968, Middlesbrough

North Western 18th October, 1967, Manchester toth April, 1968, Huyton-with-Roby Scottish 9th April, 1968, Ardrossan

South Eastern 20th September, 1967, Godalming 15th May, 1968, Godalming

South East Midland 12th October, 1967-Felixstowe IOth April, 1968, Slough

West Midland 17th January, 1968, Shrewsbury

Yorkshire July-November, 1967, Leeds and Bradford IOth April, 1968, Scarborough

CONGRATULATIONS

F. M. Bucknall

H. F. Griffiths

G. E. McCoy

W. Middleton

Page 77 56 56 56 30 87 87 56 87 56 30 2 87 87 56 30 30 87 23 106 25 83 25 81 80 22 108 24 81 48 46 82 56 30 56 30

COUNCIL MEETINGS

Solihull, 12th October, 1967 Solihull, 25th January, 1968 Nottingham, 21st May, 1968

EDITORIAL-TALKING POINT

An Open Invitation Latched Nozzles 0 Wad some Power

The Model Code

PROCEEDINGS

LEGAL

1968 Page 21 44 76 30 2 55 86

Aldridge-Brownhills U.D.C.-Fire in motor vehicle repair shop 51 Esher U.D.C.-Tanks not numbered 28 Glasgow-Illegal storage of petroleum spirit 28 Greater London Council-Tank wagons, no fire extinguisher, etc. 51, 110

Liverpool-Petrol incorrect octane rating 28 Shrewsbury-Kept petroleum mixtures without a licence 52 Shrewsbury-Petrol incorrect octant rating .11 o Stafford-Serious out flow of petroleum spirit 50

LETTERS

Car Ports-F. H. Molyneux Explosimeters-W. Middleton Latched Automatic Cut-off Nozzles-U. A. Bancroft J. W. Hewison J. G. Hurst R.A.T.Kemp F. A. Smith

Technical progress and all that-R. E. J. Roden The use of C02-G. A. T. Vickers Unattended self-service-R. Billings

J; H. Domoney W. E. Ruse

MISCELLANEOUS

A new tank measuring system-J. W. Hewisun

A.M.C. Reports

A.M.C. Representation

Attingham, 1968-M. C. Leal

Australia

Banishes Pumps-M. J. Chapman Book Reviews

Cakemore Terminal

Civic Amenities Act, 1967-A. F. Brunner

Comments from the Chairman

88 5 88 6, 57 58 6 5 4 31 4 4 31 43 20, 36, 79 56 71 3 91 7 43 14 54

Conveyance of inflammable liquids-C. L. Davids and W. C. R. Dale 88

Finned tubing cuts the cost 11

INDEX-continued

From bad to worse

Gas pressure testing of tanks

In Parliament

Increased safety on pleasure craft-W. J. Carvin

Legality of glass fibre fuel tanks discussed Light water development

Liquefied petroleum gas plants-F. Birkhead Mexico

New C02 fire extinguishing system-J. W. Hewison

New fire fighting technique

New service for testing electrical equipment

New thinking for fuel tank measurement

Not so funny

On stream at Shell Haven

Petrol explosion prevented Petrol leak costs £250

Page 31 106 32 39 20 75 33 31 19 87 3 87 2 2 3 56

Page

The testing of new and existing petroleum spirit storage tanksL lfil

The Seventh Wayne Engineering Conference-A. F. Sarfas 12 The United Kingdom oil pipeline 59

Unattended self service . . 73 World's biggest ship named 87

OBITUARY

R. L. Bloor 87 T. B. Hine 87 A. F. Richmond 56 A. H. Sewell 87

RETIREMENTS

Radio link in distribution of petroleum 2, 30, 56, 87 products-Anthony Hunter

Publications

Safe practices with bulk storage-J. H. B. Hornby Safety in the use of liquefied petroleum gas-B. J. Fuller

Sea Quest on trials after refit

Second largest oil tanker Secretary's Notes

Self Service-J. G. French and W. K. Wicks

Self Service at petroleum retail garages-A. Marshall

69 41 8 56 3 87 93 37 Self Service petrol stations-N. K. Whitehead and W. K. Wicks 62 Sweden 3

The conveyance of flammable liquids-C. L. Davids 17

The Criminal Justices Act, 1967 30

The day the River Tyne caught fire-C. L. Binnie 45

The hot line from Fawley 15

The nature of petroleum spirit and its hazards-J. R. Hughes 98

A. B. Aird 2 R. Bentley .. 86 J.C. Bird .. 56 H. T. Card 30 R. F. Carrington 56 E.T. Crowe 30 W. N. David 30 T.G.Henry 30 F. G. Jones 86 T. J. Metcalfe 56 R. Race 56

.THROUGH THE PIPELINE

What's on ice ? 49 What's pressing? 109 What's the hold up ? 72 Where's the vital spark ? 27 Why all the heat ? 27 Why be remote ? 109 Why offset? 49

Petroleum Officers Handbook

BY A. L. GOOD, F.R.S.H., F.A.P.H.I., A.M.l.P.H.E., A.l.H.M.

Chief Public Health Inspector and Petroleum Officer to Bishop's Stortford U.D.C.

The need for a practical handbook for the Petroleum Officer has been apparent for a very long time. Mr. Good, a Public Health Inspector with long experience as a Petroleum Officer, has attempted to fill this need.

In this book the Author is concerned mainly with the practical problems which face the Petroleum Officer with regard to his duties in ensuring compliance with the Petroleum Legislation. He also discusses fully the constructional problems relating to the storage of petroleum spirit in a variety of establishments both major and minor, laying particular emphasis on safety measures.

In addition he deals with related matters, e.g. transportation, testing, cleansing of tanks, liquefied petroleum gases, pumps, etc. The value of a technical book of this kind is obviously enhanced by illustrations and some SS line drawings are incorporated in the text showing details of installations and equipment.

This handbook is intended primarily to aid the Petroleum Officer but Fire Officers, County Planning Officers, Local Authority Engineers and Surveyors, Public Health Inspectors, Building Inspectors and Inspectors of Weights and Measures will, no doubt, find the book immensely practical and useful. Engineers and technicians employed in the ever-growing Petroleum Industry will also find the book helpful, giving, as it does, the forthright views of a practising Petroleum Officer.

CONTENTS

CHAPTER

I Introduction

II Simple Relevant Principles of Physics and Chemistry

Ill Petroleum Mixtures and Carbide of Calcium

IV Storage under Licence

V Keeping Petroleum Spirit, Solid Mixtures of Petroleum and Carbide of Calcium without a Licence

VI Existing Storage Tanks and Pipelines

VII The Interception of Oil and Petroleum

VIII The Transportation of Petroleum Spirit and Carbide of Calcium

IX The Transportation of Carbon Disulphide

X Liquefied Petroleum Gases

XI The Testing of Petroleum

XII Testing Concentrations of Inflammable Gases and Vapours The M.S.A. Explosimeter

XIII Accidents

XIV Means of Escape in case of Fire

XV Fire Extinguishing Apparatus

XVI Control and Enforcement

XVI! Conclusion

APPENDICES A-J

These include statutory and other useful forms and notices and, in addition-safety precautions when fuelling aircraft-conversion table for gases-British Standards and Codes of Practice -table of flash points, etc.

INDEX