Modernising Petroleum Legislation John Brazendale and Peter Sargent HSE INTRODUCTION There have been specific controls on the storage and use of petroleum spirit for over 120 years. The requirements of the older legislation were consolidated into the well-known Petroleum (Consolidation) Act 1928 (PCA) that was then subsequently extended via various Orders, to petroleum mixtures, carbide of calcium, compressed gases and liquid methane. Regulations were also passed concerning, amongst other things, storage in domestic premises and rules for container sizes and construction. The Act and the licensing regime it created has worked well, but it is widely accepted that it needs modernising to take account of changes to the industry and the principles of modern safety legislation. Indeed much of the original Act has already been replaced. For e x a m p l e the Act contained provisions on the conveyance of petroleum spirit by road that have been replaced by general transport legislation for all dangerous goods including petrol. At a recent meeting the Health and Safety Commission (HSC) confirmed that the work to modernise the remaining parts of the Act was important and gave approval to a 2-phase project to accomplish this. Phase 1 will remove licensing at all workplaces except retail petrol stations. Phase 2 will introduce a new regime for retail petrol stations and domestic storage. Further details are given later. Safety Policy Directorate (SPD) who lead on this project for the Health and Safety Executive (HSE) has set up a Petrol Working Group (PWG) to enable all views to represented in the development of the new regime for petrol. The PWG reports to the Flammables Sub-Committee of the Advisory Committee of Dangerous Substances, which in turn advises the Health and Safety Commission (HSC). Members of the PWG include representatives of the petrol industry, local authorities and their representative bodies, petroleum-licensing officers, technical experts from HSE and officials from HSE, DETR and other Government Departments. This paper explains the current proposals for Phase 1 and in particular how they relate to two European Directives, which currently HSE is transposing into UK legislation. The proposals for Phase 2 will be the subject of a later paper in the Journal. The Phase 1 proposals will be detailed in a consultation document that will be available in “hard copy” and via HSE’s1 web page on the Internet later this year. These proposals as with all new safety legislation are required to be subject to extensive consultation with stakeholders. In the light of comments received the Health and Safety Commission will then make proposals to Ministers for changes to legislation.
John Brazendale EUROPEAN DIRECTIVES CHEMICAL AGENTS DIRECTIVE The Chemical Agents Directive (CAD) requires employers to protect workers from chemical agents present in the workplace and from work activities involving chemical agents. The term Chemical Agents is defined very widely and in the context of this paper applies to petroleum spirit and other substances deemed to be “petrol”. The Directive is concerned with fire, explosion and health risks from chemical agents and applies to all industrial and commercial sectors.
THE EXPLOSIVE ATMOSPHERES DIRECTIVE (ATEX) The Explosive Atmospheres Directive (ATEX) requires employers to protect workers from the risk of explosive atmospheres. An explosive atmosphere is defined as a mixture with air, under atmospheric conditions, of flammable substances in the form of gases, vapours, mist or dust in which after ignition has occurred, combustion spreads to the entire unburned mixture. It therefore covers explosive atmospheres created by petroleum spirit ...etc. The implementation strategy for these two Directives is shown in figure 1 below.
Those familiar with HSE guidance over the last 25 years will note that this is a well-established set of requirements. It is consistent with the regulations concerning the management of health and safety at work and with guidance relevant to petrol such as the "blue book" - Guidance for the design, construction, modification and maintenance of petrol filling stations issued by the Association for Petroleum and Explosives Administration (APEA) and the Institute of Petroleum. The impact of DSEAR on the diligent employer should therefore be very small although there may be some costs to companies who have not previously carried out or recorded their risk assessments. Overall, DSEAR can be seen to be an expansion of the general duty to manage risk under the management of Health and Safety at Work Regulations 1999, making explicit good practices for dealing with fire and explosion risks from dangerous substances such as petrol.
PROJECT TO MODERNISE PETROL
The health requirements of the Chemical Agents Directive are to be implemented by changes to existing health legislation, mainly the Control of Substances Hazardous to Health Regulations (COSHH). In addition there will be some changes to legislation on asbestos and lead. On the safety side it has been decided to implement CAD and ATEX together in new safety regulations known as the Dangerous Substances and Explosive Atmosphere Regulations (DSEAR), which will deal with fire and explosion risks from dangerous substances such as petrol and which will modernise and repeal over 20 pieces of old legislation.
DANGEROUS SUBSTANCES AND EXPLOSIVE ATMOSPHERE REGULATIONS (DSEAR) The main requirements of these Regulations are that employers and the self-employed must: * Carry out a risk assessment of any work activities involving dangerous2 substances; * Provide technical and organisational measures to prevent and control the identified risks; * Provide equipment and procedures to deal with accident and emergencies; * Provide information and training to employees.
PHASE 1 WORKPLACE CONTROLS Phase 1 will remove licensing from the workplace and restrict it to retail petrol stations and domestic storage. It is HSE’s view that DSEAR provides a comprehensive framework for controlling the safe storage of flammable liquids of all types in the workplace, including petrol. There is little justification for maintaining the level of control of a licensing regime for storage. In the workplace (unlike retail petrol stations) the public has restricted (or no) access and employees are required to be trained and supervised. The removal of licensing in the workplace will remove duplication of legislative controls and inspection activities and provide some significant cost saving t industry as a whole although the cost for an individual business is small [A fee is currently charged for licensing]. Safety of petrol storage will therefore be assured by the requirements of DSEAR enforced by HSE Inspectors and Local authority Environmental Health Officers (EHOs) as part of their normal routine health and safety inspection at these premises. The removal of licensing will also mean that Regulation 20 (and, therefore Schedule 12) of the Carriage of Dangerous Goods by Road Regulations 1996 (CDG Road) will no longer apply to the unloading of petrol from road tankers in the workplace. However, the HSC has asked us to introduce an Approved Code of Practice (ACOP) to cover that activity. It is currently being prepared with assistance from the PWG. In addition to storing petrol some workplaces have dispensing facilities both for their own vehicles and, in some cases, for their employees. In the majority of cases the amount of fuel on site is small, dispensing activities are limited and the public is generally absent.
As with workplace storage, HSE believes that DSEAR is sufficient to control the risk at such sites and the licensing of such activities can be abandoned. However we are aware that some stakeholders disagree with these views believing that the current arrangements for licensing of workplace dispensing of petrol should remain in place and therefore we propose to consult on this issue as part of the formal consultation process mentioned above.
OTHER LEGISLATION Under the Petroleum (Consolidation) Act there are a number of “Orders” which are now outdated, namely: * The Petroleum (Carbide of Calcium) Order 1929; * The Petroleum (Mixtures) Order 1929; * The Petroleum (Compressed Gases) Order 1930; * The Petroleum (Carbide of Calcium) Order 1947; * The Petroleum (Liquid Methane) Order 1957. Removal of licensing in the workplace will mean that all Orders made under the Act will be effectively disa p p l i e d in the workplace as well. We are content that DSEAR and other safety legislation provide adequate controls to do this. However we intend, for the moment to keep the Liquid Methane Order in place, as there have been recent proposals to store liquid natural gas for use as a vehicle fuel, which need further policy consideration. In addition we are proposing as part of phase 1 to completely repeal the Carbide of Calcium Orders and the Compressed Gases Order as they relate to substances no longer kept for sale to the public or to circumstances where the controls have been replaced by more modern legislation. The combined effect of the above will be that, until phase 2 of the project is completed, the liquid methane order will remain in force everywhere; and the petroleum mixtures order will remain in force in places outside of the workplace. PHASE 2 There is general agreement that the current licensing regime for controlling the safety of petrol at filling stations and for controlling domestic storage is outdated and in need of modernising. The Health and Safety Commission has recently confirmed the establishment of a project to develop options for a new regulatory regime including enforcement arrangements for retail petrol stations, petrol tanker unloading and for domestic storage. In the meantime existing licensing controls are to be retained. The proposals, which would also be subject to consultation, are currently being developed by the PWG but are likely to include a form of consent or check of the design and build standards for new petrol stations, and for any significant modifications made to existing ones. It is proposed that petroleum licensing officers would be responsible for this new legislation and a fee would be payable. Operational matters would be controlled via DSEAR.
ENFORCEMENT OF DSEAR AT RETAIL PETROL STATIONS DSEAR would normally fall to district-level local authorities (EHOs) to enforce except where the major activity was motor vehicle repair (but minor retail dispensing of petrol) where HSE would be the enforcing authority. EHOs currently enforce general health and safety at work controls for Liquefied Petroleum Gas (LPG) used for automotive fuel in petrol filling stations. LPG as an automotive fuel is growing in use mainly for environmental reasons. We consider that the new Directives present an opportunity to bring an improved coherence to enforcement of fire and explosion risks at sites whose main activity is retailing of petrol. We propose therefore allocating responsibility for enforcement of DSEAR (which covers both petrol and LPG) to the existing petroleum licensing authorities for all activities at these sites except motor vehicle repair. At sites that have a mixture of motor vehicle repair and retail petrol PLAs would be responsible for DSEAR in relation to dispensing and HSE for any other application of DSEAR at the premises. CONCLUSIONS The above proposals describe the steps being taken to modernise petrol legislation. In the first phase it is proposed that in the workplace existing licensing controls will be replaced by DSEAR. A Consultation Document is at an advanced stage and consultation on this will take place later this year. Work has already started on Phase 2 developing the new regime for domestic storage and for retail petrol stations. Further details will be given in a later paper in the Journal. We are happy to receive any comments on the above matters or clarify any points. CONTACTS DSEAR John Brazendale. Tel No: 0151-951-3432. Email: john.brazendale@hse.gsi.gov.uk
PETROL Peter Sargent. Tel No: 0151-951-3264. Email: peter.sargent@hse.gsi.gov.uk
1www.hse.gov.uk 2 The term “dangerous substance” is to be used in the Regulations rather than “chemical agent” as the latter is not a familiar term in safety legislation. The scope will be the same as the Directive.
RISK ASSESSMENT PROGRAM of UNDERGROUND STORAGE TANKS Author: GS Holt Oil Industry Corrosion Control Group Cape Town, South Africa April, 2001
Oil Industry Corrosion Control Group PO Box 714, Cape Town 8000. ph: +27-21-4037443 fax: +27-21-4037854 steve.holt@caltex.co.za
SYNOPSIS This paper introduces the Risk Assessment Program
(RAP) developed by the South African Oil Industry Corrosion Control Group for the testing of Underground Storage Tank (UST) systems such as those found at petrol filling stations. These UST sites have been found to vary greatly in terms of characteristics and the risks they pose to human health and the environment. RAP recognises this diversity and uses a systematic approach to evaluate potential risks and prioritise corrective action. Factors effecting the service life of UST’s are discussed with particular reference to corrosion, which is responsible for the majority of leaking UST’s. The fundamentals of corrosion will be presented which will serve to introduce the testing and control of UST corrosion. The principal tasks associated with the RAP process will be outlined on a flowchart that will serve as an introduction to methodology of RAP. The following aspects of RAP will be covered in the paper:
RAP assessment - involving a desktop exercise and site survey to record site information RAP evaluation - evaluation of site information to assign risk ratings RAP classification -classification of site according to risk evaluation RAP controls -assignment of measure required to reduce site risk RAP management -integration of data to compute statistics and trends
* A UST system refers to the tank itself, connecting piping and ancillary equipment. INTRODUCTION Studies carried out by the Oil Industry Corrosion Control Group (OICCG) have revealed that the life expectancy of UST’s varies substantially depending on soil conditions, proximity to direct current electrified traction systems, quality of coating, etc..
Poor construction standards and defective materials are the main reason for UST failure during the first few years of service. Thereafter corrosion becomes the principal cause of UST leaks. Failure statistics show that the pipes connected to a UST are particularly vulnerable to corrosion induced leaks. Internal corrosion of UST’s in hydrocarbon service is rare and virtually all incidence of corrosion induced UST leaks result from external pitting corrosion. Recent concerns for the environment, health and safety have led to new regulations governing UST installations used for the storage of hazardous substances. For example, UST’s are manufactured to new design codes which inhibit corrosion and provide containment of leaking product. Risk assessments have become an essential part of managing UST risk. Risk assessments can identify measures to limit the exposure to unnecessary liabilities; protect capital investment; reduce the cost of repairs and replacement; provide public safety and compliance with regulations; protect the surrounding environment; and avoid costly remediation. FACTORS CONTRIBUTING TO UST RISK Refering to chart 1: The results of a life study of failed UST’s found very little relationship between age and failure. Inspection of UST’s involved in this UST life study revealed that the majority of UST failures resulted from external pitting corrosion. *[1]
Referring to chart 2: The results of risk assessments carried out at service stations located throughout South Africa show a strong correlation between corrosive soils and leak histories. It is not uncommon to find a 40 year old incident free UST in non-corrosive backfill whilst a UST buried in corrosive soils may fail within the first 5 years of service. [2]
Pitting corrosion, crevice corrosion, microbial induced corrosion are but a few forms of corrosion. The three main categories of electrolytic cells effecting UST’s are: Galvanic cell - dissimilar metal electrodes in a common electrolyte; Concentration cell - similar metal electrodes in a dissimilar electrolyte; Electrolytic cell - an electrochemical cell controlled by an external current source. In each of these cells, the anode is consumed while the cathode is protected against corrosion. The rate at which metal is removed is proportional to the amount of electric current discharged at the anode.
* Numbers in brackets refer to numbered references on page 8. The accumulated effect of minor spills and undetected UST leaks also pose a serious long term environmental risk. A service station design should include containment areas around filling points. Operating procedures should incorporate accurate inventory analysis that is able to detect UST leaks.
The use of dissimilar metals such as steel tanks and galvanised pipes may lead to galvanic cell corrosion. The diameter of a tank may influence the intensity of concentration cells between the top and bottom of the tank. This is due to fluctuations in oxygen, moisture, soil composition and temperature that exist at different depths in the soil. Stray direct currents in the earth can lead to very rapid electrolytic cell corrosion. Microbial induced corrosion can also accelerate corrosion of UST’s in anaerobic soils such as clay. Some of these corrosion processes are depicted in the figure on the next page.
CORROSION TESTING REGULATIONS Most regulations governing UST’s acknowledge that a storage facility should have the following minimum requirements: [3]
* It must prevent releases as a result of corrosion or structural failure for the life of the facility;
* It must have adequate corrosion protection or be constructed from a non-corrosive material; * The materials of the tank or liner must be compatible with the product stored. In the interests of preserving the environment, legislation has made it mandatory to assess and manage risk at sites that are regarded as major hazardous installations. Non compliance with these regulations may have serious implications for service owners. [4]
FUNDAMENTALS OF CORROSION Corrosion of buried steel may be defined as the electrochemical destruction of the metal due to a reaction with its environment. At the surface of a corroding metal there are active electrochemical cells where electric current is discharged from the anode, which corrodes, and is collected by the cathode, which is protected. [5]
We have seen that corrosion is largely an electrical process and hence it stands to reason that the corrosion activity on a metal surface may be determined by measuring its electrical status. [6] Soil resistivity measurements are used to determine the corrosiveness of the backfill soil. The lower the soil resistivity the more conducive it is to corrosion activity. Further soil tests to determine the values of the pH and aggressive ions such as chlorides and sulphates may also be useful for further corrosion analysis. [7] Structure to soil potentials are useful in determining the corrosion activity between the metal surface and its environment. Generally, the more positive (anodic) the structure to soil potential, the more conducive the structure is to corrosion activity. Structure to soil potential surveys are also used to determine the presence and magnitude of stray DC current which can result in very rapid electrolytic corrosion.
CORROSION CONTROL The most common method used to protect buried steel from corrosion is to apply a coating. Defects in a coating expose the steel substrate to corrosive electrolytes. This results in a concentration of corrosion at these small areas of uncoated steel. It is for this reason that cathodic protection is often used to supplement corrosion protection at coating defects.
We have seen that corrosion occurs at the anode, which discharges current, which is collected by the cathode where corrosion is iliminated. It stands to reason therefore that if the entire steel surface can be made to act as a cathode, in other words to collect current, then no corrosion will occur. Cathodic protection is achieved by forcing an electric current to flow through the soil towards the surface of the steel to be protected, thereby making the steel collect current and act as a cathode.
RAP ASSESSMENT The Risk Assessment Program (RAP) developed by the Oil Industry Corrosion Control Group (OICCG) is a fully integrated software system specifically designed to asses and control the risks associated with UST’s.
RAP includes a desktop exercise to record site details, construction details and site history, as well as a site survey to determine the site characteristics and environmental sensitivity. The desktop exercise compiles the following data:
RAP PROCEDURE The principle tasks associated with the RAP process are outlined in the following flowchart: [8]
Site details - Owner, description, site code, operator, address details.
Construction details - Building details, UST capacity, UST material, pipe material, and overfill protection. Site history - Leak history, leak detection, land usage, public image, product throughput, site inspection and maintenance details. The site survey is conducted to determine the following: Environmental details - Population density, soil type/permeability, depth to ground water, proximity of boreholes, distance from surface water, and water use. Site characteristics - Soil resistivities, structure to soil potentials, stray current influence, soil pH, CP current drain details.
RAP EVALUATION The results of the desktop exercise and site survey are used to determine a RAP rating for the construction, history, environmental and characteristic of each site. T h e RAP ratings for each of these elements are combined to calculate an overall RAP grade and Failure Prediction Index (FPI) for each site. The RAP grade and FPI identifies and prioritises the control measures required to reduce the risks associated with each site. The RAP database is also combines the site RAP ratings to evaluate regional risk values associated with towns or magisterial regions. Regional assessments are useful in identifying areas of concern where RAP surveys and control measures may be prioritised.
RAP MANAGEMENT RAP is a dynamic program, which automatically adjust the risk associated with corrective measures taken to reduce risk such as the installation of cathodic protection and site changes such as age. RAP is also used to compile statistical data, for example the performance of UST’s in various corrosive environments.
RAP is also linked to a Geographical Information System (GIS). Capturing the information of a retail network within a GIS has many potential applications, the most apparent being the positional details and attributes of the network. The strength of GIS is its ability to synthesise the network information. It can thus be utilised as a decision support tool and when used in conjunction with RAP, it becomes a powerful risk assessment tool thereby facilitating easier communication and the prioritisation of risk management resources. CONCLUSION There are large risks associated with UST systems. These risks can be controlled given the correct attention to risk management. The main conclusions are: *There is little relationship between the age and failure of UST’s; *There is a strong correlation between corrosive soils and UST leak histories;
* Regulations can have serious implications for non compliant UST operators;
RAP CLASSIFICATION RAP classifies each site into three main categories: A high RAP grade and high FPI designates a high-risk
*Steel UST’s are exposed to aggressive electrolytes and will corrode if not protected;
site that is susceptible to leaks. This category of site would require further investigation such as inventory analysis or Vacusonic testing. The option of replacing UST’s or retrofitting cathodic protection (CP) depends upon these test results.
*Corrosion is largely an electrical process that can be measured and controlled; *RAP provides a systematic approach to assess and reduce UST risks;
A high RAP grade and low FPI designates a high-risk site with a low leak susceptibility. CP in this case becomes an attractive option to reduce corrosion and hence leak probability. A low RAP grade and low FPI designates a low risk site requiring little in the way of remedial measures other than those necessary to address regulatory compliance.
*Combining RAP with GIS provides a powerful decision support tool.
REFERENCES 1. OICCG “UST Life Study”, Presented at the Caltex Branch Managers Conference, Cape Town, RSA,
assign
1977. 2. OICCG RAP statistics, 1998. 3. OICCG “Review of EPA Regulations”, 1991. 4. Major Hazardous Installation code, 1998 5. OICCG “Cathodic Protection”, presented at the BP
recommended control measures necessary to reduce the risk at each site. Depending on the classification of each site these may include inventory analysis, vacusonic tank testing, repairs, replacement or abandonment, cathodic protection and leak detection wells. The decision as to which control measures to apply is taken in consultation with the site owner after due consideration for safety, economics and regulations.
Field Engineering Conference, Itale Game Reserve, RSA, August 29, 1995. 6. OICCG “CP of Above Ground Storage Tanks”, ICC conference, Dubai, UAE, 1992 7. Chevron Corrosion Prevention Manual, November 1989 edition. 8. OICCG “RAP presentation” 13th ICC, Melbourne, Australia, 1996
RAP CONTROL MEASURES RAP uses a unique risk
matrix
to
Stage Vapour Recovery is Pointless As Observed by Jack Gall Thomson Unless the equipment on the service forecourt is capable of gathering all the vapours as the motorist refuels.
The motorist has to be the key to ensuring that all the vapours are collected when he refuels, provided that the nozzles he is offered are capable of true vapour recovery.
Sadly, the motorist, wth the best will in the world, can currently do very little to help the environment, faced as he is with an assortment of refuelling equipment and methods which, as far as he is concerned, have changed very little since I was a Pump and Tank Supervisor with Esso in the mid 1950’s. Why did the fuel suppliers rightly scrap top loading of tankers, and leave their customers to be still splash refuellingt a quarter of a century later? Cartridge recharging was an idea based on the 1920’s two gallon can, but obviously fell by the wayside. So, here we are on the twenty first century forecourt with petroleum vapours wafting all around and some noises made about recovering them and converting them back to liquid.
a. Some nozzles have recovery facility, but make little or no attempt to seal off the tank filler neck, and consequently can pull in large amounts of atmosphere.
I am sure there is a big pay back, both environmentally and financially, to the fuel supplier who gets the method right, but I do not think anyone has much stomach for it, and will offer the inevitable chestnut excuse of .... costs. This is, of course, a valid argument and has to be accepted as important along with others such as alternative fuels.
b. Some nozzles have a form of cowl on the spout which, when properly applied in to the filler, can create a reasonabe seal round the neck. c. Another version is similar to (b) but has a pliable cone rather than a cowl. d. Finally a nozzle was fitted with a spout which carried a cap which was supposed to screw in to the filler neck. The individual merits of the above vary according to the purse or ideals of the operating companies, but, one thing is certain, the average motorist has not the slightest idea of what is supposed to be going on, no matter which nozzle he is presented with.
So what steps can be taken to assist the motorist? He or she is now almost in the category of an untrained operator with a part to play unwittingly in helping the environment.
NEVERTHELESS, DO N O T DESPAIR, READ O N
...... RETURNING TO THE HEADLINE ABOVE
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Clearly, nozzle (a) should have a cowl or cone to seal the vapour parth from the masses of oxygen it must currently be pulling in to the system. This sould also bring it in to a more familiar pattern to line up with (b) and (c).
I think we can forget (d) until such time as every motor filler has the same thread. Equipped with any of the above, the motorist has a reasonable chance of sealing the vapour path from escape to atmosphere or vice versa PROVIDED .. he or she keeps the cone or cowl seal up tight to the filler neck. Sadly, this can not be guaranteed, even in countries where the loony latch for the trigger is banned. People wedge the trigger open with the filler cap or whatever, and other just rest the weight of the hose in the fillwer neck. All this breaks the vapour path seal. So what can be done? An intense publicity programe with reference to the absence of dangerous vapours, both on the forecourt and nationally would help, but indifference and plain laziness oculd still sabotage it all.
..
To ensure an acceptable seal, the answer has to be a form of proximity device fitted to each cowl or cone seal. So that is this device, and how would it help?
...
A PROXIMITY DEVICE, as its name implied, is a low cost sealing cone (or cowl if it suits the nozzle manufacturer) which has the facility of sliding on the outside of the nozzle spout. The distance of slide is restricted, and once again is designed around a particular spout, and, in that position, is has a marked affect on the ability of the nozzle to pass liquid. In other words, when the seal is down the spout, one can get not response from the trigger. Insert the spout in to the filler neck and the seal will impinge on the filler rim. Continued insertion in to the filler, and the sealing cone will move up the spout against the spring bias.
As this is happening, an internal link between the cone and the body of the nozzle will adjust the trigger mechanism to permit normal function, and fuelling can commence. This state of affairs will abide until, either the trigger is realeased by hand or by the auto-shutoff, OR BY RELAXING THE PRESSURE O N T H E CONE SEAL IN T O THE FILLER. In all cases flow will cease immediately. Should the latter be the result of the motorist being distracted, relaxing or plain lazy, then flow can be restarted by releasing the trigger, pressure the seal back again, and pulling the trigger. The pressure required to maintain flow in minimal, about 10 Newtons. The above describes the “dry” type of device, and generally speaking this needs minimal modification to the existing range of nozzles, and varies in simplicity. This cannot be a retrofit, although existing nozzles could be works modified.
A “wet” system has also been developed which only requies a change of spout, but as the name implies, a small burst of product is ejected before the unit refuses
to allow fuelling. Other than that, the function with cone seal etc. is just the same. At the present time, this is not available on all models of spout, but work is continuing to make this a low cost retrofit system with a universal coverage. The menace of the leaking seal is also being looked at by experimenting with “ram-in” cones on the spout. As with the possibility of the screw in seal (d) the variants of filler necks and their location to the edges of the filler recesses, make this a very long and uncertain development. Obviously, much co-operation between fuel supplier, nozzle maker, designers and approval authority is needed, and I am sure that the public will quickly find that is is in their interests to maintain the seals ... particularly if they are in a hurry. I am also aware that the loony latch lovers will not like it, but a healthier and safer system on the forecourt must warrant serious consideration.
Stage 1B Testing - Friend or Foe! By Rodney Carter of Petroman Environmental Services Limited Testing Stage 1B might well be considered by many as yet another administrative chore to be dealt with by a forecourt manager already overburdened with paperwork, with little or no acknowledgment for its relevance, (save having the test certificate hanging on the notice board). The more enlightened will accept that by having a test carried out and having site personnel aware of how Vapour Recovery Systems are designed to operate, affords a complete understanding of a very significant and important piece of forecourt equipment.
A Vapour Recovery System that passes a comprehensive and thorough test will ensure that deliveries can be carried out efficiently, but more importantly, safely and with minimum risk to the tanker driver, whilst the integrity of the system meets the sites environmental responsibilities. Our testing method was introduced some two years ago and is designed to be an interactive process undertaken whilst a delivery of product to the site is taking place). Since then we have carried out well over five hundred individual tests. Unfortunately the results are very revealing, with a very disappointing percentage of test passes. Over this period we believe that we have probably encountered most of the problems associated with Stage 1B but not all.
DELIVERIES Receiving a delivery of product to the site is just as important as the actual Vapour Recovery System itself as they are both directly related to one another. TANKERS It is important to recognize how important the efficiency of the deliverytanker is in minimizing the problems related to Stage1B.
Taking these facts on board dictated that the extent of the testing of a system had to be expanded in order to meet these requirements. With over fifty check points for each system and with comprehensive information collated during the test it is possible to offer an extremely comprehensive report for each site. This information may not be what people want to hear, but it is increasingly irresponsible to ignore this information, as the inevitable will happen one day. StagelB has been in operation for many years now and many systems have been operational with out any noticeable defects. However many sites have been converted to Stage 1B with little regard to the requirements of Vapour Recovery or for its compatibility with the equipment already on site, which had not been designed to be used with such a system.
To further aggravate the situation, works carried on these systems have caused more problems than they have resolved. It has to be recognised the many changes have taken place within the industry since the introduction of Stage 1B. The introduction and changing of use to Unleaded products, the increases in Diesel usage and Stage 2 have all compounded to put stress on a standard Stage 1B system. Therefore it is not surprising that so many systems are not meeting the operational requirements expected of them. As already mentioned the delivery cycle is the most critical part of Stage 1B, as much for the protection of the environment, but more importantly for the safety of staff involved in this operation and more specifically the tanker driver, especially as driver controlled deliveries are increasing.
So what have been found to be the main problems and there causes within Stage 1B.
DROP TUBES During the two years of testing, we have found the tankers to have been operationally very good with only a fraction of a percent of them operating inefficiently. This fact has helped to mask the very real inefficiencies that we have discovered in many of the systems we have tested.
A simple “rule of t h u m b for a Stage 1B is that a good system with an inefficient delivery tanker produces a low risk of problems with a delivery. Similarly a good, efficient tanker delivering to a poor vapour recovery system is equally a low risk. A good tanker delivering to a good efficient system is no risk. However combine a poor site system with a poorly performing tanker and you really have all the potential for real danger.
These have proved to be the greatest problem that we have come up against. Mainly due to excessive vapour leakage either via the overfill prevention valve or the actual sealing on the lip at the top of the drop tube. They have been removed in all manner of conditions, some due to ill fitting, others just not meeting current requirements. Leakage from the fill pipe is at a rate dependent on the venting pressure during the fill cycle. We have tried to achieve a total sealing to avoid any pressure escaping through the drop tube. The importance of this has been borne out by our suppliers, who have in turn increased their specification
on pressure testing prior to supplying us with their valves. We still have to use our own sealing rings and cages, but giving a three-year warranty for this work has meant sealing the top plug. If the seal it broken then we will not accept responsibility for the vapour tightness of that tank unless it has been checked and re-sealed by ourselves. The failure rate has proved to be exceptionally low so far, but we are looking to the future to considerably longer periods of warranty.
PRESSURE\VACUUM VALVES These are not so critical, but there is an improvement in the reliably factor. During our testing we do give a tolerance especially on the release pressure. Once the valve has released under controlled testing, the re-seating is very important. Not many have failed due to the vacuum side of the valve, but if this is the case they are exchanged immediately.
VAPOUR CONNECTION VALVE They generally seem to be very reliable, but this is very dependant on their location i.e water corrosion etc.
FILL CAP COVERS Fill caps suffer from missing seals and heavy handling but that is to be expected but the sealing is most important.
PIPE WORK Leaks mainly due to vehicle damage or modifications over time not being done as well as might be expected.
FILL PIPES Flow Rates are an important part of the test to see if they match the range expected of them.
With a trend towards higher volume sites, wear and tear on Vapour Recovery Systems is inevitably going to increase and it is therefore even more important that the operational efficiency of each system is closely monitored.