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Pipelines safety regulations 1996: Guidance on 'Pipeline Operator'


This guidance supplements the HSE Pipeline Safety Regulations (PSR) guidance document L82 on the meaning of "pipeline operator". It is applicable to both onshore and offshore pipelines.


The arrangements for operating pipeline systems are often complex. There may be different pipeline operators of parts of the system and complicated commercial arrangements. This sometimes results in confusion over who the pipeline operator is.

Guidance on determining the operator

PSR reg. 2(1), defines the "operator" in relation to a pipeline as:

  1. the person who is to have or (once fluid is conveyed) has control over the conveyance of fluid in the pipeline;
  2. until that person is known (should there be a case where at a material time he is not yet known) the person who is to commission or (where commissioning has started) commissions the design and construction of the pipeline;
  3. when a pipeline is no longer, or is not for the time being used, the person last having control over the conveyance of fluid in it.

Notification to the HSE of the pipeline operator

The pipeline operator must notify its role to HSE. HSE will not decide who the pipeline operator is, but will take action if the notified pipeline operator cannot fulfil the range of duties specified in PSR.

Some duties apply to all pipeline operators but if the pipeline is a major accident hazard pipeline (MAHP) there is an additional duty to prepare a major accident prevention document (MAPD). The operator could prepare this  through its own resources or through others. But it must have sufficient competence and authority to make proper decisions and maintain control of the safety and integrity of the pipeline.

Therefore a holding company with no employees and set up purely to hold the pipeline assets could not be the pipeline operator.

Where there is a parent body with several subsidiaries or a joint venture with several partners, then the various parties should decide between them who will be the pipeline operator.

"Control over the conveyance of fluid"

To have control over conveyance of the fluid requires management arrangements, clear responsibilities, authority, competence and access to information to be able to make proper decisions about the safety and integrity of the pipeline. This is more than just carrying out processes, such as controlling the operation of valves.

The following criteria will normally need to be satisfied before a person can be considered to have control over the conveyance of fluid in a MAH pipeline. They must be in a position to demonstrate that:

Joint ventures and similar arrangements will need to agree who can make these demonstrations.  


Owning a pipeline or the fluids conveyed in it does not, by itself, confer control over the conveyance of fluid in a pipeline. A person may be the pipeline operator and not own either the pipeline or the fluids.

The owner of a pipeline, or a consortium of owners, may appoint a person to operate the pipeline. The person appointed would have to satisfy requirements outlined above.

Different operators for different parts of a pipeline

PSR Regulation 17 requires co-operation between operators of different parts of a pipeline. One operator may act as the "co-ordinating operator" in monitoring conveyance in a pipeline system and may require other operators to ensure that the necessary adjustments in fluid flow, composition, condition, quality, etc. are made in order to safeguard the whole system or part of it. However, each operator will be responsible for the safe operation of their part of the pipeline. 

Clear boundaries should be established between the pipelines forming a pipeline system. Ideally these should be at physical boundaries, such as a valve or pipe joint. Less clear or distinct boundaries, such as the edge of an offshore installation safety zone or a chemical plant fence line should wherever practicable be avoided. Examples where clear physical boundaries might not be practicable are:

Notification before construction and operation: initial and subsequent intended operator(s)

Once the person who is to have control over the conveyance of fluid in a MAH pipeline is known then that person is the pipeline operator. Where that person is not yet known, it is the person who commissions the design of the pipeline or (where such work has started) the person who commissioned the design and construction who is the pipeline operator.

This pipeline operator must notify the HSE before construction of a major accident hazard pipeline can commence, (PSR regulation 20).

Before the design of a MAH pipeline is complete the pipeline operator must prepare a Major Accident Prevention Document (MAPD) (PSR regulation 23).

If there is a change of pipeline operator through the commissioning, construction and operating phases, that change should be notified under PSR Regulation 20.

Contracts and commercial arrangements

A pipeline operator may place contracts with another person to operate, inspect and maintain a pipeline, possibly with full day-to-day "control". However, this does not transfer their duties. Pipeline operators must ensure the safety and integrity of the pipeline is ensured by, for example, an effective audit and verification system.

References to pipeline operator under legislation other than PSR

Other legislation, such as the Petroleum Act 1998 and associated works authorisations for offshore pipelines, use the term 'operator'. These may not  establish who the operator is under PSR.


Issue Date: 19 February 2008
Gas and Pipelines Unit

Updated 2021-02-24