Annex 1: High Level Plan to replace LPG buried metallic service pipe work


Members of UKLPG, the trade association for the LPG industry, the HSE, are committed to work together with consumers to ensure the replacement of underground metallic service pipe work. HSE has been working with UKLPG since early 2007 to develop plans for the replacement of buried metallic pipe work.  It is in the industry's, its customers' and the wider public interest that this pipe work is replaced within the shortest timescale that is practicable, but a timescale that is realistic, achievable and reflects the risks. This annex brings together, in summary form, UKLPG and HSE's plans to achieve this.

There are some key issues that must be addressed to enable a comprehensive plan to be compiled and the work itself undertaken to meet ambitious timescales. Nevertheless, UKLPG members consider that delivery of a programme to replace at-risk underground metallic pipe work at commercial and industrial installations, by the end of 2015 is feasible, with the highest risk being prioritised and replaced sooner. This view is based on three key influencing variables being addressed:

  • Prioritisation and understanding the risk of current metallic pipe work installations
  • Numbers of skilled operatives
  • Duty holders fulfilling their responsibilities

These are described below.

The prioritisation of the pipe work replacement will be based on a risk model developed by Germanische Lloyd (GL), who are being funded by HSE to extend and tailor the model, originally developed and used for the prioritisation of the replacement of natural gas pipelines, specifically for metallic LPG pipe work. A comprehensive and wide ranging survey is currently being carried out to capture the relevant characteristics of each LPG installation to provide the data required by the model. The output of the model will be a list of sites ranked by risk which will be used to set the priorities for the pipe work replacement.

Although replacement work has already started, once the data is available from this prioritisation exercise, the work will be ramped up from October 2009.

The LPG industry are also working with the gas competency standards setting body to develop standards and training materials to be used to conduct a training programme to increase the number of skilled fitters certified to carry out the pipe work replacement in a safe manner.

Alongside this, HSE are preparing to carry out an inspection campaign in parallel with the pipe work replacement, designed to secure agreement from LPG users to have their pipe work replaced where required. Inspectors from HSE and local authorities will carry out the campaign. The work will be allocated on the basis of existing HSE/LA enforcement responsibilities for industry and commercial sectors. The inspections will focus on sites prioritised as high risk and will cover the complete LPG installation, including the tank and any associated valves and regulators.   The preparation work, now in progress, consists of producing guidance material for inspectors, training them in what they need to look for and planning the programme of site visits.

At the same time, HSE plan to update the current user guidance material and will support UKLPG and Institution of Gas Engineers and Managers in reviewing the supplier and installer codes of practice. It is planned to update the currently available information leaflet 'Checking your LPG pipe work' for LPG users and provide a generic risk assessment for industrial/commercial companies to use to assess the operation of their LPG installation against current best practice. HSE also plan to provide technical guidance on the application of cathodic protection to existing metallic pipe work installations.

HSE are currently reviewing the strategy for domestic installations, and are working closely with industry to agree a coordinated approach. This is an HSE initiative which goes beyond the remit of the Gill inquiry and which the HSE considers essential in order to ensure that the safety of domestic users is given the same priority as that of commercial and industrial users. Work is in hand to better understand the risks to domestic users, to consider possible sources of advice and support, and to assess the best approach to communicate with domestic users. Industry will work with HSE and its appointed consultant, TTAC, with the aim of developing a plan of action and customer communication during the fourth quarter of 2009.

The overall timescale for the completion of domestic pipe work replacement is dependent on fully understanding the real risks to domestic users. That said, industry will work with its domestic customers to replace highest risk domestic pipe work within the same timescales as set for commercial/industrial customers.  Individual LPG companies are already engaged in working with their customers to replace pipe work assessed as likely to being most at risk.

HSE and UKLPG will hold regular meetings to assess progress and review priorities as the pipe work replacement progresses. We plan to hold a senior management review meeting every six months to formally review progress and resolve high-level issues.

Key Influencing Variables:

1. Prioritisation and understanding the risk

The work will require prioritisation, both between higher and lower risk installations and between domestic and commercial/industrial consumers.
Work is already in hand to carry out a risk analysis of commercial and industrial customer installations based on the responses to a detailed questionnaire, and the outcome of this will be brought together with known data on domestic installations to produce an overall risk ranking for each. This will be available for consideration and planning by mid September and will provide the basis for prioritisation.

Notwithstanding the above, there is an indication from an HSE commissioned report that for domestic installations the majority of low-pressure metallic pipe work may be at significantly lower average absolute levels of risk than first assumed. HSE have commissioned further work to help determine the relative and absolute risk to people and to assist the development of information sources for domestic LPG users. UKLPG believes that understanding this is critical to establishing a plan that truly reflects the risk - both in order that the available resource is used to best effect, and that customer's worries are not unduly raised.

According to an estimate of the number of installations with underground metallic service pipe work, there are between 15,000 and 40,000 industrial/commercial installations and between 24,000 and 54,000 domestic installations of a similar kind.  To this needs to be added 400,000 static caravans supplied by LPG, many of which are supplied by bulk LPG  (these figures are hidden within the total commercial numbers above which include  numbers of caravan sites rather than individual caravans).

Detailed planning depends on the output from the GL model, which is designed to produce a risk ranking on a scientific basis taking into account soil corrosivity and permeability, ground cover etc. Whilst every effort is being made by LPG supply companies to achieve a full customer response, with encouraging results to date, we must acknowledge that the percentage of complete and comprehensive replies which will be achieved is currently an unknown factor. Further work is planned to understand the risk ranking of caravan metered estates and the resource requirement to replace metallic service pipework in these locations.

2. Numbers of skilled operatives

There is a shortage of skilled operatives to carry out the work.
The above report estimates one full staff day per domestic installation, and two full staff days per commercial installation, to excavate and replace the service pipe work. On this basis 100-300 staff years will be required to replace the high and higher risk pipe work as estimated in the report. Based on these numbers, this gives an approximate requirement for 600 staff years to replace all installations.

Based on a working year of 231 days the estimated numbers of installations would require resource to deliver 27,720 staff days per year to deliver replacement of all installations within 5 years but this does not take account of a number of factors:

Variation to estimates of total and at risk installations:

There is the potential that the number of industrial and commercial installations with underground metallic service pipe work could be up to 33% greater than the estimates from the above report and those of medium pressure 50% greater reflecting the age of this market as well as the different appliances and processes in use compared with the domestic market. Medium pressure industrial and large commercial premises will demand greater time and resource with potentially multiple skilled operatives, so the average time commitment as estimated by the report may be on the low side for more complex installations.

Other tasks and demand on operatives' time

The reality is that the actual number of competent LPG qualified Gas Safe registered engineers required will be many times more than a simple extrapolation of people from the total staff hours needed.  This is because we will have to allow for, not only potentially complex and longer individual location replacement, but also normal exigencies of work such as imperfect scheduling, regional concentrations, sickness, cancelled appointments or travelling time as well as other demands on the operatives times.  Each competent LPG qualified Gas Safe registered engineer is likely to require the support of a labourer to undertake the evacuation work and making good the installation following replacement of the metallic pipe work with PE pipe work. Additional LPG company resource will be needed to manage the customer relationships, administer the communication, schedule and prioritise work leading to final delivery of the replaced pipe work to the satisfaction of the customer. 

It is anticipated that arrangements to increase the number of suitably qualified engineers can be put in place by the end of 2009, but that it will take the following year to build up the numbers of personnel with the required competencies.

3. Duty holder responsibility

The duty for the replacement of pipe work, in general, falls on the customer.
As part of the data gathering process, commercial and industrial customers are being made aware of their responsibilities. An initial letter was sent to such consumers in 2006 together with the HSE's 'Checking your LPG pipe work' leaflet making them clearly aware of the responsibilities. Some companies sent out a follow up letter the following year and, in mid June 2009, a further letter was sent together with the HSE/UKLPG questionnaire.  This set in train a communication exercise that will result in all commercial and industrial customers being made aware of the risk levels of their pipe work and the action they need to initiate in order to eliminate this risk.

Utilising the output of the work to assess the risk factors relevant to domestic installations, we hope to make domestic consumers with pipe work that may be most at risk aware of their situation by the end of 2009.  We aim to ensure that this communication is as comprehensive as possible.

The reaction of both domestic and commercial/industrial customers is difficult to predict - there may be urgent demand to complete work, even though the location in question is not deemed of the highest risk. Equally, there may be reluctance of the duty holder to spend money in tough economic times over an unseen and unperceived risk. The objective of the HSE inspection campaign will be to ensure that commercial dutyholders take the necessary steps to replace their pipe work. Similarly, the objective of the domestic strategy will be to provide the domestic customers with the information they need to decide what they need to do in order to replace their pipe work where necessary.

See also

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Updated: 2022-02-16