The Bulletin – November 1980

THE BULLETIN

Journal of the Association for Petroleum and Explosives Administration

I

INDEPENDENT -FUEL"

NOTES AND NEWS

LONDON NEWS SHELL ON THE MAPLINS

IGNITION BY RADAR

CONTENTS GAUGES SHELL ROAD TANKER

CONTENTS GAUGES

The Bulletin

Published by the Association for Petroleum and Explosives Administration

Opinions expressed in this Journal are not necessarily the views of the Association 1

NEW PRODUCTS 25

Talking Point

The Health and Safety Commission have produced the second consultative document on Dangerous Substances Conveyance by Road Regs. The Association along with other interested parties were given a few weeks to comment on these new proposals. Again the HSC has failed to listen to the arguments for enforcing. I find it difficult to believe in the present political climate that the HSC are encouraging BUREAUCRACY by making additional authorities responsible for such matters when the expertise and manpower already exists.

It will be interesting to see if they maintain their "head in the sand" attitude when the document is produced before parliament later

this month.

Honorary Secretary Mr. E. Brown Cambridgeshire County Council

Honorary Editor Mr. J.A.J. Thompson,

Baby Brown

Members who have seen the Hon. Secretary will have noticed him wearing a large smile and handing out cigars, no he had not been promoted; his wife has just given birth to a baby boy. Congratulations Mr & Mrs Brown.

The Association welcomes the following new members

Corroshield Ltd Associate member

Mr. J. Siddel Associate member

Mr. J. Wright Associate Member Blevex Ltd

E W Taylor Fuel Control Ltd

Associate Member

Mr. W. Dunbar Co Tyrone

Mr. J. Cook Surrey CC

Mr W. Slatcher Kent CC

Chief Fire Officer West Glamorgan

Mr. Whi t e Berkshire

Mr Pinder North Humberside

Mr. Jones Manchester

Mr. D Clarke West Yorkshire

Mr Hills Cambridgeshire

Mr. I. Mr. A. Duncan Brown

BP Cape Town South Africa London Brick Company Ltd.

PRO VISIONS APPROVED FOR EXEMPTIONS FROM CONVE YANCE LEGISLATION

Regula ti ons e mpo wer i ng the Health and Safety Execut ive to grant e x emptions f r om the c onve y an c e p r o v isions of t he Petrol e um (C o n sol i dat i o n ) Ac t 1928 and r elated l e g isla t ion , we re l ai d before Pa r liame n t The y c ame i nt o op e r at i o n on August 28 , 1 980

Drawn up b y t he He a l th an d S af e ty Commi ss i o n and ma d e by Mr . No rm a n Fo wle r, Minister of Tran s port, the r e gul a t io n s a r e intended to a llow some de gr e e of flexibility in impl e me nting th e requir me n ts of the Act, which contain s no provi s ion f or e x emption and so account cannot be tak e n of modern developments in technology which offer opportunitie s for the safer transport of hazard ou s substance s.

Any application for under these regulations will be carefully scrutinised and granted only if the Ex ecutive is satisfied that in the circumstances of the particualr case, the grantin g of an exemption will not prejudice the health and safety of persons likely to be affected by it.

The regulations were prepared in consultation with the CBI, TUC, local authorities and other interested bOdies including government departments. The Health and Safety Commission has also drawn up the consultation procedUres to be adopted by the Executive when considering any application for exemption

Any correspondence concerning the possibility of exemption should be addressed to:

HM Explosives Inspectorate, Thames House North, Millbank, London. SWIP 4QL

giving details of the particular conveyance regulation from which exemption is sought and the reasons why it is thought necessary. The inspectorate will then discuss with the applicant the technical evidence to be provided before the exemption is considered.

The Petroleum (Consolidation) Act, 1928 made no provision for the granting of exemptions. The Act, and conveyance regulations made thereunder, is bein g replaced by three sets of regulations dealing with conveyance by road tanker and tank container, packaging and labelling and conveyance of packages. Until these regulations come into force, technological advances which will improv e the safet y of conveyance of dangerous substances cannot be implemented unless exemptions can be g r anted

The main pu r poses of these g eneral regulations are :

to d e al with anomali e s and unf or se en conti n ge nc ies fo r which n o p r ovision wa s made i n t he Pet r oleum ( Conso lidat io n ) Act 1 9 28;

To dea l with spe c if i c prob le ms o n whic h c erta i n of th e s tr i ct control s a p pli ed b y t h e 1928 Act ar e not n e c ess ary to e n su r e health and safety, and wh ere s tandard s will be maintain e d at an a de quate leve l or, indeed , improved by the particular exemption proposed .

It is understood that vehicles engaged in the removal of waste petroleum products (waste disposal vehicles) will be among the first to benefit from these exemption regulations.

Conveyance of dangerous substances by road

The conSUltative document describing revised proposals for extending and updating existing legislation on the conveyance of dangerous substances by road was published on 8 July 1980 and is available from HMSO, price £3.00 plus postage, ISBN 0 11 883270 O.

Commen ts are iari ted up to 31 Augus t 1980 on the first part of the revised proposals, the Dangerous Substances (Conveyance by Road in Road Tankers and Tank Containers) Regulations 1980 and the Approved Code of Practice on the Classification of Dangerous Substances, which the contained in the document.

A CODE FOR CONTROL OF STATIC ELECTRICITY

Static electricity occurs commonly in indus try and in dai ly li fe and can be a source of danger as well as discomfort or inconvenience. The main hazard is that of explosions and fires initiated by electrostatic discharges but shocks to personnel can on occasions cause accidents. One of the factors in avoiding these hazards is the provision of effective earthing and bonding.

BS 5958 Code of Practice for the control of undesirable static electricity is to be produced in two parts. Part I General considerations, which is now available , gives basic information on the various ways static electriCity can be inadvertantly generated in solids, liquids and gases and also on persons. It outlines the methods available for minimising the generation of static charges and for safety dissipating charges which are produced.

The recommendations on earthing given in Part 1 have been developed to take account of the fact that static electricity is frequently associated with plastics, vessels, pipelines and the like which preclude the provision of a resistance to earth of the order of that demanded for earthing of electrical equipment.

Part 2, which is in course of preparation, will give detailed recommendations for controlling static electricity in particular industrial situations.

Copies of BS 5958 Part 1 may be obtained from BSI Sales Department, 101 Pentonville Road, London NI 9ND. Price £14.50. (BSI Subscribing Members £7.25).

Classification, packaging and labelling of dangerous substances

The Commission have agreed to the publication of a consultative document incorporating proposed amending regulations to the Packaging and Labelling of Dangerous Substances Regulations 1978.

The amending regulations are required because of a new EEC adaptation directive which amends the original Council Directive 67/548/EEC which was implemented by the existing 1978 regulations.

publication of the consultative document is expected by the end of August/early September and copies will be obtainable. from HMSO. A period of three months will be allowed for comments.

Notification of accidents and dangerous occurrences

Regulations simplifying and extending the law on notification of accidents and dangerous occurrences at work were laid before Parliament on 24 June 1980 and are due to come into force on 1 January 1981.

The regulations, drawn up by the Commission after extensive consultation will apply to virtually all work activities. Copies of the regulations, Notification of Accidents and Dangerous Occurrences Regulations 1980 (SI 1980 No 804) are available from HHSO, price £1. 25 plus postage.

The Health and Safety Executive will publish guidance on the regulations later in the year.

The Association has been asked by Normend lnstruments to remind our members of a questionaire recently sent to all 120 Local Authorities responsible for petroleum licensing. Mr Peter Norfolk of Normond instruments told The Bulletin of 120 forms sent out only 21 replies have been received. The questionaire is about the requirement of Local Authorities for contents gauges and if they require nylon or copper tubing between the gauge and balance chamber. The are anxious to advise potential customers of the area they will be supplying and it is felt that this is a time that Authorities can assist industry. The company are also interested in those who require"fail to full" gauges and those who require constant reading gauges. Should your Authority not have replied ar you wish to help please contact the company Normand Instruments Ltd 25, Kewfoot Road, Richmond Surrey tel 01 940 7373.

ConSUltative Document

The consultative document describing revised proposals for extending and updating existing legislation for conveyance of dangerous substances was published on July 8th. Comments from interested parties were invited up to August 31st. The APEA following the seminar earlier this year were prepared for this rather short comment period and a full Council meeting was held and the document was considered. The following letter is the reply sent to the HSE.

Mr. H.A. Gates, & Safety Executive, 27th August, 1980.

Dear Sir,

Dangerous Substances (Conveyance by Road, Tankers and Containers) Regulations 1980

The APEA has recently considered the proposed regulations in connection with the conveyance by road of dangerous substances in road tankers and containers and submit the following comments as invited.

Regulation 12.

Despite the intention to produce Regulations free from ambiguities the opportunity to continue control of parking of vehicles carrying hazardou loads is diluted to the requirement s 'to be parked in a safe place'. It would seem sensible to continue the control at present available in the current Spirit (Conveyance by Road) Regulatlons particularly 1.n Vlew of the public interest now manifest in all matters pertaining to the carriaee of goods by d roa .

Regulations 19 and 22.

The intention of the Health and Safety at Work Act and all safeguards arising there from is to provide a Simple monitoring structure and it fOllows a reduced inspectorate with clear areas of interest. Thus, if petroleum spirit licensing authorities are to remain enforcing authorities for the purpose of Regulation 19 at 'petroleum filling stations' as defined, it follows from paragraph 39 of the document that the responsibility for implementing the general provisions of the Health & Safety at Work Act 1974 should rest with these authorities. This is necessary if proper control is to be exercised over operations carried out by the tank wagon driver.

Under the proposals, a local authority inspector empowered to carry out the petroleum function, on witnessing an irregularity associated with the tank wagon would need to call in another enforcing authority to deal with the offence, a clumsy and impracticable exercise. It is considered that Regulations 19 and 22 should be amended to make the petroleum licensing authorities responsible for enforcement when an offence is committed on a 'petroleum filling station'.

The provisions of Regulation 19 should be extended to refer to all tanks whether or not on a 'petroleum filling station'. Accidents occur at premises other than those in the category mentioned and it is difficult to understand why the omission of control is proposed when the degree of risk is comparable.

The defence of an alleged offender that he took all reasonable precautions and exercised due diligence to avoid committing that offence, is one used in other legislation and which has been found to be ineffective. It is suggested that this be ommitted from the proposal.

Yours faithfully, EriC B. Brown. Hon. fecre tary .

CONVEYANCE OF DANGEnOUS GUBSTANCEe

From B.O. LOWE Bedfordshire

New regulations, which are at present in draft form, concerning the conveyance of dangerous substances, are currently being circulated to interested parties by the Health and Safety Executive for comment.

The main effects of these regulations would be (a) to revoke all existing similar legislation controlling the bulk conveyance of dangerous substances/liquids, e.g. The Petroleum-Spirit (Conveyance by Road) Regs. 1957, and (b) to place responsibility for enforcement of these regulations (with the exception of unloading of petroleum-spirit at a filling station) with the Chief Officer of Police where the vehicle is on a road and in any other case with either the Health and Safety Executive or an officer of the local District Council as determined under the Health and Safety (EnforCing Authority) Regulations, 1977.

Before 1974, a multiplicity of rural, urban and borough councils were responsible for enforcement of this type of legislation with the consequential diversity of interpretation, variation in degree of enforcement and a general lack of uniformity so far as industry was concerned e.g. in my own relatively small county there were 13 different authorities enforcing their own Conditions of Licence under the Petroleum (Consolidation) Act, 1928. In 1974, responsibility for such matters was placed with 'top tier' authorities, who delegated this function either to the local Fire Brigade or Training Standards Department, and no one can deny the tremendous improvement in safety conditions, so far as both conveyance and storage of such substances is concerned, which has taken place since 1974.

If it is now the intention, albeit innocently, to return such enforcement duties to District Councils through the devolved powers available to the Health and Safety Executive, then I would suggest that this is a completely illogical and retrograde step which will only lead to duplication of responsibility in licensed premises, and confusion to all concerned. If the Health and Safety Executive do not have tne manpower to enforce this legislation, then why not leave it in the hands of the existing expertise? What is eve'l more disconcerting is that at a recent seminar organised by the A.P.E. in Cambridge, neither the Police nor the District Councils appeared to be aware of these proposals!

Most licensing authorities have an excellent relationship with both police and fire authorities and agreed emergency procedures in the event of accidents. When accidents do occur they usually have their own major problems to deal with and are usually only too pleased to hand over the 'legal' side to the local Petroleum Officer when hazardous substances are involved.

It is accepted that these proposals will only apply to 'conveyance' but I would earnestly request the appropriate officers of the Institute to make the strongest possible representations to the Health and Safety Executive in order that the existing wealth of experience in this important safety area is not wasted to satisfy some bureaucratic whim. Of course it may on second thoughts be the foot in the door?

Cylinder explosion

While petrol was being drained from the tank of a Jaguar car into an open vessel in a double lock-up garage in Willesden petrol overflowed and was ignited. During subsequent fire-fighting operation an acetylene cylinder, one of a number of cylinders in the garage, exploded causing injury to nine fireman

The only defect found was a leak on a pump and this was rectified. The smell and four members of the public and damage to nearby windows. The remains of a homemade lead lamp were found in the ruins of the garage. The occupier of the garage

of petrol in the house continued intermittently and appeared to emanate from a duct enclosing a soil ventilating pipe which passed through the living room of the house. Eventually a sump was dug on the edge of the forecourt as near as Possible to the soil pipe in the house to collect any petrol which might have been left in the A disused well was discover d during the dig. The water in the well e _ . was not nor did the sump show an traces of petrol. y

In the meantime the householder expressed concern for the health of his famil was prosecuted for the Petroleum Sporit (Motor Vehicles, etc.) Regulations 1929 (see item 3 (e) following).

Digging problem

A deep trench being excavated for new sewer pipes in a road outside a petrol filling station in Richmond showed signs of contamination with petrol when dewatering plant was used to remove water from the trench. Advice was given to the engineer about ventilation of the trench and prohibition of smoking, and the Factory Inspector was informed. The usual checks were carried out at the filling station but nothing untoward was found.

As excavation proceeded along the road the sewer pipes were laid and the trench backfilled. The nuisance abated and finally cleared up once the filling station had been passed.

The filling station had been in operation for 45 years; it seems probable that minor spillages over the years had collected in the ground and had been peleased when the trench was excavated.

11 d Y and ca e 1n someone to measure the concentration of lead in the atmos h S f kn P ere.

o ar as 1S ow, nothing was re 1 vea ed to cause any concern. The matter was I t d a so rep or e 1n the local press Compl'a1nts f1nally stopped. It should be noted that the householder declined to accept d' a V1ce on how to stop the smell getting int soil pipe duct. 0 the

Welding incident

During welding operations on the cill of a motor car in a small garage Workshop in Kingston, the plastic fUel P1pe runn1ng from the fuel tank to the melted and leaking petrol was 19n1ted by the welding torch. I the ensuing fire three cars and mostnof the stores and equipment were de t s ,royed Fortunately, cylinders of acetyl ene and oxygen rema1ned intact although their gfaughes partially melted by the heat o t e f1re which was extinguished by two jets.

Boy burnt

Petrol was spilled onto the floor of lock-up garage in Croydon while an a employee was draining a car's fUel tank While investigating a of a The employee started to sweep th .' smell of petrol in a publ1c house cellar into the yard watched by th e SP11lage in Bexley, the inspector found that the another employee. The . petroleum interceptor on the forecou:t of and the boy sustained bUrns to his gn1ted the petrol filling station had been 1nstalleoan d legs in the ensuing fire hi h back in reverse. However, the smell continued quickly put out with foam c i was t Th 1ngu shers and a suction line became suspec. e line was taken out of use and there have The cause of the fire is something of a been no further complaints. The petroleum mystery as the employee did not smoke the car's b tt h d ' interceptor defects are being remedied. a ery a been disconnected and there was no other apparent

UnsatiSfied customer

On receipt of a c,olUvlaint: from a Richmond householder of petrol smells in his dwelling the petrol installation at a nearby filling station was checked.

source of 1 9 nit10n .. Theoretically it is Possible that a bU1ld up of static electricity on the nylon bristles of the brush may have sparked on discharge to earth during the sweeping operation but this is an unlikely cause.

Chambers interceptor petroleum

Issue of a prohibition notice

On being advised by a Divisional Fire Prevention Officer that motorised caravans in a railway arch in the Hackney were being used as living accommodation arrangements were made for a joint visit by a petroleum inspector and officers representing Fire Prevention, Building Regulations Division and the Borough Environmental Health Department.

Some forty motorised caravans were parked, partly inside the arch and partly in the half covered yard outside. The occupier of the premises was charging £2. per person each night for sleeping in a caravan. The arch, which is 31 metres long and 10 metres wide, was completely blocked at one end and means of escape in the event of fire would have been difficult. As the use contravened No. 5 of the Petroleum Spirit (Motor Vehicles, etc.) Regula tions. 1929 auu tUtl arrangelilen ts were considered to provide a serious risk of personal injury, a Prohibition Notice was served under the Health and Safety at Work, etc. Act 1974 by the petroleum inspector. The Notice required the immediate cessation of the use of motorised caravans for residential purposes in the arch.

The premises were again visited at 23.30 hours on the following night when it was found that the Notice was being complied with.

To ensure continued compliance the premises have again been checked.

Baffle failure

The two compartments (5000 and 3000 capacity) of a new tank being l.nstalled at a filling station in were tested satisfactorily by the l.nspector using the air on water method. When the manlid was subsequently rem?ved for fitting pipework it was notl.ced that the baffle between the two compartments had come away from the tank shell. site foreman admitted that on completl.on of the al.·r on t wa er test he overlooked releasl.·ng th e pressure sl.multaneously from both c ompartments. The baffle was too warped to be of further use and a flat bulkhead suitably braced was fitted in lieu. The tank then passed another air on water test without further incident.

Smell of petrol in a flat

When investigating a complaint of a smell of petrol received from the occupier of a flat in a housing b!ock in Muswell Hill the inspector found that a neighbour was keeping five gallons of petrol in an unlabelled plastics container in his kitchen in contravention of Nos. 2,4,5(d) and 7 of the Petroleum Spirit (motor Vehicles etc.) Regulations 1929. Proceedings were instituted for the offences and the person keeping the petrol was fined £100 on each of the four offences with £130 costs at Highgate Petty Sessions.

Proceed.ings by Surrey County Council

Item in a previous LONDON NEWS described an incident at a filling station on the Greater London/Surrey border involving outflow of petrol into London from the premises during tank wagon delivery. One of the G.L.C.·s senior petroleum inspectors had initially dealt with the incident.

Surrey County Council instituted proceedings against the licensee, and employee of the licensee and the tank wagon driver.

The licensee pleaded guilty to two counts, of (a) failing to give notice of spillage and (b) failing to take due precautions to prevent spillage. The licensee was fined £800 on (a) and £300 on (b).

The employee pleaded guilty on two counts of (a) failing to ensure no petrol overflows and (b) failing to keep constant watch. He was fined £40 on (a) and £60 on (b).

The tank wagon driver was also fined on two counts of (a) allowing petrol to enter drains and (b) failing to see a certificate signed before making a delivery. He was fined £10 on (a) and £40 on (b).

Contravention of a Regulation.

The occupier of a lock-uP garage was fined £400 with £40 costs at Willesden Magistrates' Court for a contravention of No. 10 of the Petroleum Spirit (Motor Vehicles, etc.) Regulations 1929 which prohibits the exposure of petrol near any fire or artifical light liable to ignite flammable vapour.

The offence arose following a fire which had severe consequences (see item l(c) above)

Rubble trouble

When the smell of petrol in a dwelling house near a petrol filling station in Brent was investigated recently, the tank records at the filling station indicated an apparent loss of 90 gallons. Because the tanks were only being dipped weekly instead of daily, however, it was not possible to estimate the period over which the loss had occurred.

Subsequent tests revealed that a suction line was leaking; when the line was exposed it was found to have been surrounded with rubble instead of concrete. When another suction line was exposed, it too was found to be surrounded with rubble, furthermore, it was corroded, although not holed. The licensee has been required to renew, as necessary, any other lines which are similarly installed. He has also been cautioned for the infringement of the licence condition about the keeping of records.

LEGAL PROCEEDINGS

a) Infringements of Blackwall Tunnel By-laws

i) A haulage firm was fined £50 with £10 costs in connection with the conveyance of acids through the tunnel. The case was heard at Greenwich Magistrates' Court.

ii) At Thames Magistrates' Court the driver of a lorry was fined £50 with £25 costs and the owner of the lorry was fined £50 for taking synthetic lacquer in drums through the tunnel.

iii) Also at Thames Magistrates' Court the driver of a tank wagon containing perchloroethylene was fined £50 with £25 costs and the owner of the vehicle was fined £50.

b) Unlocked manlids

The owner of a petrol tank wagon was fined £100 with £25 costs on each of two contraventions of No. 12(2) of the Petroleum Spirit (Conveyance by Road) Regulations at Hampstead Magistrates' Court. Both contraventions related to unlocked and insecurely closed manlids.

SHELL.

ON THE MAPLlNS

The Editor

Shell are at present conducting a series of tests on the Maplin Sands off the Essex coast to try and discover the problems of large scale spillages of liquified petroleum gas. The Bulletin has recently published the thoughts of Professor Rasbach on the large scale leakage of LNG and the associated problems. (Vol 18 No 3). The experiments are being carried out on the Ministry of Defence firing ranges at Shoeburyness away from residential areas. To date the tests have been carried out on which has in fact burned and behaved as The amounts released in these tests equals a ten ton load, or that of a road tanker. The liquid gas released onto the sea water from a pipe at the rate of two tons a minute is later ignited ano the burn is then registered on a series of instrumented pontoons anchored about 3C0 m from the centre. These then record air/gas mixtures; rate of flame spread, temperatures etc which are then fed into a computer to be analised. In addition to this system other experiments have been made by filling a barge up with the liquid gas then sinking it in the sea. Dr John Homer the project manager has reported that the gas released has burnt at high temperature, but drifting over open water has caused no explosions. It has been made clear that large LNG clouds released in a built up area may behave &ifferently than over open water. Tests have more involved propane , and these will cease on November 1st when the project will be closed down The tes t s have been carried out throughout the summer while weather permitted and a de ci s i on will be taken by the company on continuation of this e x pe r iment a f te r an a ppr a i s al of the data s o f a r collected, and if there is money avai lavl e for more r e searc h . I understand that t he pr o j e c t wi ll have cost She l l in th e r eg i on of £3m. The t ests ar e att r a c t ing i n t e r est t hro ughou t t he world and the US De partment of Energy i s carrying ou t s i milar res e arch in Cal iforni a . She ll ar e to b e comme nde d for their r esearch into this area which is causing concern to envirome ntali s ts and s af e ty officers.

IGNITION BY RADIO FREQUENCY

British Standard 4992

By H.T.E. Jackson Senior Petroleum Inspector Greater London Council

Consideration of this problem has arisen due to a case where interference with the electronic controls of a pump on a filling station near Heathrow Airport occured due to the presence of a nearby radar aerial. This type of interference is not likely to be of a matter of concern for us ; although it may affect the limiting device , but possibly more so the Consumer Protection Authorities. This can however be rectified by adequate screening ot the pump electronic circuits.

This occurence did bring to light the existence of the above mentioned British Standard concerned with the ignition hazards arising from radio and radar fields.

I have considered the matter from two aspects.

1) Specific hazards relating to airfields where radar exists

The case of interference from radar at Heathrow has been investigated by the Civil Aviation Authority and although they state that energy levels measured did not exceed the safe limits laid down in the B.S. it is clear that they must have closely approached them since action was taken to revise the operating characteristics. The aerial has in fact been removed but this was due to other considerations.

It would appear that radar installations can cause an ignition hazard at considerable distances and that this fact should be bourne in mind when considering applications for new petroleum installations in or near to airfields. The same consideration should be applied to military premises where radar exists. Should the hazard be likely then advice should be sought from the appropriate authority ( the address of these are given in the appendix of the B.S.).

Apart from fixed installations there are radar sets fixed to aircraft At Heathrow no aircraft would normally come within the hazard distance of petrol installations ( given in the B.S. as 10 metres for such radar). During fuelling of an aircraft the operation of its radar is forbidden by C.A.P.74 and also by licence if petroleum spirit fuel is involved.

It occurs to me that ships on tidal rivers also may carry radar but I have not investigated this aspect. The Port Authorities should have rules governing such use.

2) Possible hazards from redio transmitters operated by car hire firms etc.

I have consulted the Radio Regulatory Department of the Post Office and am informed that the maximum permitted power allowed is 25 watts and that the frequencies allocated for such use are within the range of 72-470 MHZ. Although there is no specific example for a fixed installation of these parameters in table 2 of the B.S. a mobile transmitter of any frequency and with a maximum transmitted power of 100 watts is stated to offer no hazard providing there is no direct contact with the aerial. I think it would be reasonable to conclude that a fixed installation of 25 watts maximum permitted power would be equally safe and that no specific regard need to be taken of such an installation in relation to licensed storage except for the usual hazard zones.

Although not mentioned in the British St&ndard another paper on this type of hazard did show there could be a risk of ignition if a mobile transmitter was used whilst the vehicle in which it was being used was refuelled. It was found that a spark could occur under these conditions between the filling opening and the pump nozzle. The only way in which this risk could be covered would be an appropriate notice at all filling stations; but I do not consider this justified as other electrical apparatus on cars being filled could also offer similar risk.

Since writing the above an amendment to the British Standard has been issued which states in effect that the figures in it are not to be relied on and that further research is proceeding. However I do not think it likely that these would affect the situation in cases such as discussed above.

CONTENTS GAUGES

G I WOOD K D G Instruments Ltd

Self-Powered Automatic Contents Gauges -(Picture 1)

The H.C.G. (Hydrostatic Contents Gauge) Series of level indication has been supplied by K.D.G. to all major industries in the U.K. and worldwide for over 30 years. Continuously indicating, without outside source of power, the level of a wide range of liquids including water, oil, petroleum spirits and heating oils.

Transmitter units can be externally or internally mounted and are connected to the indicator by a predetermined length of P.V.C. armoured capillary tube. External types are supplied with a -i" B.S.P. non-return valve, enabling the instrument to be removed or fitted with liquid in the tank.

The most popular indicator used is the weatherproof "Polyrad" indicator which is shown here (Picture 1).

Operation:- Pressure Transmitter a capsule connected by the capillary to the indicator. All are charged with an lnert gas. Pressure applied to the capsule compresses the gas and moves the pointer on the scale.

Simple Design

Robust construction Reliable operation Remote or local indication Calibrated to usersl requirements.

The Tronic Series

This were of a

Series of level indication was developed for the installations where large distances between measuring point and indication point or the gauge and transmitter was in a difficult position. '

there installation

The transmitter uses a capsule transformer mechanism developed by K.D.G. and over the yea:s proved and robust. This transmitter is connected to an indicatlng gauge, ldentlcal ln appearance to the H.C.G. Polyrad, via a power supply box, with copper cable.

The added advantage being that an S.G. correction adjustment can be fitted in the Power Supply Unit.

pictures 2 and 3 show two typical transmitter units. Picture 2 can be lowered on the cable to the base of a tank, whilst Picture 3 is the pole mounted version for top entry. flanged units are available, one as picture 4, another with a flush dlaphragm for chemical applications which is not illustrated but details can be readily obtained by contacting K.D.G. at Crawley, Telephone Crawley (0293) 25151.

A Shell road tankel the forecou rt. But ( (other, of course, tl bland exterior, imn

· is a common enough site on jo you know what lies inside it lan motor spirit?) Behind its laculately painted in the Shell

decor, lies a complexity of compartments and / engineering. We asked artist Tony Garrett to find out about all this, and to make a drawing. This is what he discovered.

CONTENTS GAUGES

PETER NORFOLK NORMOND INSTRUMENTS LIMITED

Normond Instruments have since 1945 produced Tank Contents Gauges for the remote indication of tanks containing practically every liquid. The following is a short discription of the range of instrumentation particularly suitable for petroleum storage tanks on service stations, although the same principles equally apply to industrial users Who use the Normond to monitor stocks of virtually any liquid product.

The three systems later described are firstly the well known and almost universally accepted "G" range hand primed Tank Contents Gauges. The second describes the changes when continuous air supply allows for continuous readings of the instrument and thirdly the electronic type Tank Contents Gauge DGl introduced two and a half years ago.

" COUPLING 02130 : , , ".-

• MIN. SPACE REQ'O ,:' 3 FOR HEAD OF '. -.l BALANCE CHAMBER

"G" Type Manually Primed Instruments

Over thirty thousand "G" type Tank Contents Gauges have been produced and installed on petrol tanks enabling the operators to completely dispense with the necessity of manually dipping tanks. The advantage of this system means that forecourt managers no longer have to rely on operators lifting heavy manhole covers and dipping in inclement weather, with the obvious disadvantage of inaccurate readings.

The "G" range consists of three components namely the gauge head which is a precision low range pressure gauge calibrated in terms of capacity, an open ended tube which is inserted into the tank and called a balance chamber, and connecting tubing between this balance chamber and the gauge head. The Normond "G" Series Gauges use the hydrostatic principle of proven reliability and simplicity and requiring no outside source of power. This method involves minimum labour in installation and gives important advantages in the safe measurement of volatile liquids. The operation of a small hand pump positioned at the base of the instrument head charges the Normond system with air under pressure. Liquid is thereby displaced from the balance chamber on the bottom of the tank while excess air escapes to atmosphere. The resulting pressure within the balance chamber is measured by the low range pressure gauge which actuates a pointer to show a calibrated reading proportionate to the head of liquid in the tank. is no flexible diaphram in the Normond gauge to puncture or replace.

There Hand pumping dispenses with sealed capsules. The system allows for full flexiibility in the positioning of the indicator which may he disconnected at any time without upsetting the calibration of the instrument.

Regulations governing the use of the equipment are limited to the require-ments by various authorities of minimum spacings b e tween each increment on the dial to a minimum of 8mm between each 100 gall mark subdivded into SO or the nearest metric equivalent when using litres. An optional requirement in some areas is that ins tead of using 270 degrees of dial, ie starting wi th zero and ending at full, the instrument employs 360 d egrees and incorporates a fail-safe feature that should the capiliary tubing between gauge and tank become dislod g ed or displaced, th e instrument inst e ad of falling back to zero position, "fails to full". Th e s e instruments can be r e adily recognised du e to a red sector on the dial at its lowest point.

Continuous Air Supplies Tank Contents Gauges "G" Range

These Systems incorporate the same dial type as before but are all of the "fail to full" type. The balance chamber is similar but has two connections instead of the one, and two connecting lines. The first to the instrument and the second to an air control device. This air control device dispenses wi th the necessity of the hand pump. Two types are in use (A) the air controller type P2E which incorporates an electrical compressor and failsafe equipment, restrictors etc., and (B) the air controller type P2A which receives raw compressed air from the site compressor. Of the two systems Normond would recommend the P2E due to the inherent unreliability of normal site compressors which once down would then also negate the Tanks Contents Gauge system. It is obviously important that when supplying com-pressed air of any type to a tank that this should be limited to below the maximum working pressure of that tank. Therefore the mini compressor is incapable, no matter how treated, of pressurising the tank over and above its normal work;ng .L pressure. The amount of air which arrives at the tank is minimal due to the requirement that the pressure in the balance chamber is only variable with slow changes in height. This amount of air is restricted to below one qua t r er of a cubic foot per hour •. The P2A has two regulators, one reducing the sit e sompressed air to a tolerable level of say 40 psi and the second regulator filt out impurities and reducing the pressure further to around 5 psi. Both of the regulators incorporates fail-safe features in that any drastic increase in up-stream pressure reduces the output in the same proportion. T he P2A air controller is used only when the site prohibits the use of a P2E b , ecauSe of its proximity in a Division 2 Area. The advantage of continuous reading equipment, ;s h .L t at the operator need do no more than read the instrument, but obviously requires some outside source of power -whether site compressor or a mains SUPply for their use.

Tank

Contents

Gauges for the 80's

Due to the intervention of electronic engineering a further development has become available in the last few years which has removed the requirement from a bellows operated movement actuating a pointer over a defined length, and replac ed this via accurate pressure transducers 1.Thich in fact translate mechanical energy into an electrical output relative to volume. The system incorporates the balance chambers as per the other systems, therefore requiring no electrical connections at the tank end. Air is supplied to the balance chamber through a similar system as the P2E air controller. The operation of the equipment is by push buttons numbered as per the tanks. On selecting a button the pressure within a given balance chamber has access to the presSure transducer. This pressure deflects a silicon wafer, which on one side has a resistance printed upon it. Full range deflection on such device is only three or four microns but the change in electrical output is signi-ficant and accurate enough to be sent through a series of preprogrammed calculations incorporated W1°th1°n h ° t e equ1pment. It has access to the memory of given site conditions, namely tank numbers, sizes etc., and translates this pressure into terms of capacity either in gallons or litres, or in the case of bulk storage, ie acids, into tons, etc. Comparisons with the all-up capacity of each tank can be accessed through a further button on the equipment. Interface facilities are available for use with petrol pumps or remote data collection with the equipment, as is a special printer incorporating time and date with each printing. The printer is an alpha-numeric dot matrix electro-sensitive type using metal electro-sensitive paper. The use of this printer avoids possible fraudulent tampering or overtyping. The printer interface incorporates an automatic scanning device which on command, will read all contents throughout the range of tanks for a given site.

The now very substantial demand for such instruments has been growing in the last few years due to rapid product increases and more competiveness of service stations. It complies with one of the demands from petrol companies in that the Tank Contents Gauge stock position can be accessed from any point along with pump readings, cash till amounts etc., and although on-line systems are mainly in experimental stages these instru-ments have the facility to link-up with other equipment of the future.

THE NORMOND DGl PRINTOUT DATA

The PRl/PR2 DGl printer is alphanumeric, dot matrix, electrosensitive, using standard rolls of metal electrosensitive paper which incorporates a thin metal layer of al.uminium by pulses of electric current via a sliding head carrying thus not requiring ribbons or ink. The use of the printer avoids possible fraUdulent tampering or overtyping. The printer interface incorporates an automatic scanning device and a qrrartz controlled twenty four hour clock circuit, which prints the time and date on each reading taken from the instrument.

contents of tank li tres

tank number "fUll tank" capacity indicat ( or prlntout When capaci ty button depreSsed)

NEW PRODUCTS

PEIROLEUM SPIRIT LEAK DEl'ECIDR

The 'LEAK X' System carprises a detector cable, control cable and Monitor Unit and will rapidly detect the presence of Petrolernn Products in liquid fonn.

DEI'ECIDR CABLE.

This is a twisted pair of conductors insulated with a degradeable dielectric affected by liquid hydrocarbons. The cable is vulnerable to all Petrolernn Products and will deteriorate in a time interval dependant on type, temperature and quantity of the product. The standard cable is available either unprotected or arnoured for use in situations where cable protection is required.

CONTROL CABLE.

This has the same electrical properties as the detector cable to ensure consistency in fault or leak location. It is used to connect the detector cable to the Monitor Unit.

M)NITOR UNIT

This device continuously 'reads' the cable and its tenninating resistor. lmy change in cable impedance will activate an indicator. Single or Multiple units are available ·working from 115 or 240 Volts A.C.

'!HE SYSTEM

If Petrolernn Liquid is present due to leakage or overfilling, it will attack the sensor cable insulation causing the cable impedance to vary. This in turn affects the Monitor Bridge circuit. The inbalance of this circuit is used to activate a warning light and can also be used to energise auxilliary equiprent such as audible alanns or equiprent shutdown. Test points along the sensor cable can be installed to locate the leakage area. The equiprent is the subject of a BASEEFA Certification of Monitor as Associated Electrical Apparatus, EExia 11 C to BS 5501 Part 7 1977 (EN 50.020) Le Intrinsically safe, and the System Exia 11C to SFA 3012 1972 all specified in their letter of Intent dated 3.12.79.

PORTA PROBE

can be used by untrained personnel and is reusable. It corrprises a perforated steel auger base 1 meter in length plus 3 x 1 meter perforated steel extensions., f our meters of Leak X sensor cable and a portable battery operated

PEIRO PROBE

The permanent 'In Ground' probe detector system similar to the porta Probe but intended as a permanent installation linked to a fixed monitor unit.

A valuable and efficient leak detector for specially hazardous situations such as tank chambers, where vapour detectors give spurious alanns. Useful also for early leak detection in forecourt pumps thus avoiding the danger of vapour feed back to the Console Unit via the cable Porta Probe can be used to locate underground contamination by sarnplmg at various locations. Petro Probe is errployed as a pernanent sub-soil rronitoring system which would be valuable where for example an 'l.ID.derground boiler house is situated near a Filling Station Forecourt.

A NEW A1.J'lU.1ATIC FIRE AND EMERGENCY DEI'ECTION SYSTEM

Davies Linear Detector (DLD) , is a heat detecting installation which can protect large areas at low cost. The system comprises a three conductor cable fed fran a Ma.ster Control Unit by a low power supply. When required, this power supply will be Intrlnslcally Safe, confonning to CENELEC EN 50.020 Marking (EExia) 11C.

SENSOR CABLE

Th7 DID Sensor cable is a plastic insulated three conductor cable tWlsted and installed under tension. When heated, the insulation allowing the conductors to tear out of their covering and tWlSt together, thus making an effective and positive electrical The plastic employed is self-extinguishing, will not and is resistant to atrrospheric conditions. It will respond rapldly to temperature rise because the heat absorbed is rni.nirna.1. The Cable is available in three types, operating at of 60'C, 85'C or 120'C according to requirements. cable spans up to 70 rretres long are practicable and since the cable weighs only about 40 grarrmes per rretre, the installation poses no difficulties. Standard telephone or electric cable can be used to interconnect DID protection areas which are not adjacent to each other, or to connect the protection areas to a rerrote control station. The total length of DID cable can be 35 kilcrnetres with a standard control unit, and can be more than this with a special control unit. The employrrent of three conductors improves the versatility of the system which can be used to convey other errergency signals by linking the cable with any two state (CN-OFF) devices, such as SIroke Detectors, Level Alarms etc.

CONTROL UNIT

This unit constantly monitors the DLD cable and will instantly detect any short or open circuit. The unit will differentiate between Fire and other Emergencies, will locate the incident by precise rreasurement of electrical resistance, and can also initiate suitable action. For example, in the event of Fire, the unit can sound the Fire Alann, indicate the area involved and energise the Autaratic Fire Fighting Installations. The Emergency function can be used in a similar manner to switch off pumps if a high level switch operates. The unit is powered fran 115 or 230 volts A.C with a nickel cadnitnn standby' battery and associated trickle charger. It should be installed in a constantly manned SecUrity or Fire Station remote fram the detection area.

GENERALLY

The system is inexpensive to install and maintain and can easily be extended or re-routed to cope with plant or building alterations. Damaged spans can just as simply be replaced. The integrity of the plastic insulation ensures that the cable will not initiate any false alarms. It is the ideal solution for the detection of Fire in large open areas such as Tank Farms, Dnnn Storage eoop:>unds, r.ro Cylinder eompounds or Timber Yards.

Further details can be obtained fran the Sole U. K. Agents

AMEEm (HEALTH AND SAFEI'Y) LIMITED. BASILDON 284361