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The pipelines safety regulations 1996




1  This SPC provides information on interpretation of the Pipelines Safety Regulations 1996 (PSR). It should be read in conjunction with the guidance booklet L82. The regulations are primarily concerned with pipeline integrity, are goal setting in approach and encourage operators to use risk-based techniques.


Part I (Introduction - regulations 2-4)

2  Regulation 4 applies PSR to onshore and offshore pipelines and pipeline works. Offshore pipelines are covered by virtue of article 6 of The Health and Safety at Work etc Act 1974 (Application outside Great Britain) Order.

Pipelines and offshore installations

3  The definition of an 'offshore installation' under the Offshore Installations and Pipeline Works (Management and Administration) Regulations 1995 (MAR) includes any part of a pipeline connected to it and within 500m of any part of its main structure. MAR does not disapply PSR to this 500m section within the offshore installation or its associated operatorship in terms of control over conveyance of fluids.

4  Boundaries between each part of a pipeline should normally be physical, established at a valve or other means of blocking or regulating flow, or where pipelines join. Less distinct boundaries such as the edge of an offshore installation safety zone should be avoided wherever practicable. Examples of where distinct demarcation may not always be possible are:

5  Figures 2 and 7 in booklet L82 illustrate the limits of pipelines at offshore installations.

Part II (General duties - regulations 5-17)

6  Part II covers general duties, applicable to all relevant pipelines. These require proper design, use of suitable materials, safe construction and installation, safe operation, maintenance and decommissioning. This covers the integrity requirements of DCR, which do not apply to pipelines.
Part II imposes a duty on the operator not to use the pipeline unless:

7  Operators also have duties to:

8  It is an offence to cause damage to a pipeline which may give rise to danger to persons (regulation 15). There are some points to note on this regulation:

Part III (Major accident hazard pipelines - regulations 18-27)

9  Part III details the duties required for major accident hazard pipelines (MAHPs),  defined as those conveying ‘dangerous fluids’.

Notification - MAHPs general

10  Notifications should be sent to Aberdeen for pipelines in Scottish waters and to Norwich for all other offshore pipelines.
11  These duties are described in:

There is no requirement for operators to notify HSE before construction of a new pipeline, or modification to an existing pipeline, unless it is a MAHP.

Notification - new MAHPs

12  The notification details include the name and address of the operator (Schedule 4). This notification may form the first contact between the operator and HSE for that pipeline. A productive dialogue is more likely if the operator is identified to HSE as soon as they are determined, whether for a new MAHP (where the aim of notification is to trigger HSE's inspection and initiate dialogue) or where previously advised operatorship details change.
13  The operator should be able to discharge their duties under PSR, particularly those regarding the major accident prevention document (MAPD) required for major accident hazard pipelines.

Notification - multiple construction sites

14  Under regulation 20, if construction of a MAHP occurs at more than one location (for example onshore, offshore or a combination of both) and in more than one stage, notification to HSE should occur at least 6 months before the first stage begins. An example is where a pipeline bundle intended for offshore use is constructed on land and then taken to an offshore installation for final assembly and connection. Construction of the pipeline starts at the first stage on land.

Notification - other cases

15  Regulation 22 requires notification in other cases, at least three months before the event. Repositioning of ESDVs on pipeline risers is an additional example to those listed in the guidance to Schedule 5 in booklet L82.

Dangerous fluids

16  These are described in Schedule 2 by reference to certain physical properties. For offshore pipelines it is likely that all those conveying gas, produced fluids and live (‘spiked’) crude oil will be MAHPs, for example where the vapour pressure of the fluid is greater than 1.5 bar absolute at 20°C. Particular fluids are not prescribed, except acrylonitrile. There is no minimum quantity and no minimum pipeline dimensions. Methanol and glycol are not dangerous fluids under PSR.
17  Annex A is a table of fluids known to be conveyed by onshore and offshore pipelines, indicating whether or not they are dangerous fluids as defined.

Emergency shutdown valves (ESDVs)

18  Regulation 19 defines an ESDV as a valve which is capable of adequately blocking the flow of fluid within the pipeline at the point at which it is incorporated. In the absence of a definition, ‘adequate’ means sufficient for a particular purpose.

19  Schedule 3 covers a number of issues, including:

Major accident prevention document (MAPD)

20  Regulation 23 requires the operator to prepare a major accident prevention document before completion of the design of the pipeline. It should normally include:

21  The MAPD need not be submitted to HSE, but it must be kept up-to-date and should be available for inspection. It may be a stand-alone document referred to in the offshore installation safety case or it may be included in the case in its entirety.

Emergency Procedures

22  If there are different operators for different parts of a pipeline then their emergency procedures and arrangements should be compatible with each other.

Exemptions (regulation 29)

23  The circumstances which justify exemption are likely to be few and will need close examination. Guidance on exemptions is here.

Further information

24  Further information can be obtained from the OSD Legal and Operational Strategy team, 01224 252603.

Annex A

Fluids known to be conveyed by offshore and onshore pipelines

Fluid Phase Flam Boiling Point Toxic Vapour pressure Dangerous - under PSR Sch. 2
Acetone liquid F 56.5 -   no
Acrylonitrile           yes (defined)
Adiponitrile liquid F 295 T very low no
Ammonia gas F   T   yes
Aniline liquid F 184 T very low no
Benzene liquid F 80.1 T approx 0.1 bar no
Brine liquid -   -   no
Butadiene gas F+ 0.5 -   yes if above 7 bar
Butane gas F+ 0.5 -   yes if conveyed a) as a liquid or b) a gas above 7 bar.
Calcium sulphate slurry -   -   no
Carbon black powder F   -   no
Carbon monoxide gas F+   T   yes
Cement slurry -   -   no
Chalk slurry -   -   no
Cyclo-hexane liquid F 80.7 -   no
Ethane gas F+   -   yes if above 7 bar
Ethanol liquid F 78.4 -   no
Ethylene gas F+   -   yes if above 7 bar
Ethylene dichloride liquid F 82.4 -   no
Ethylene glycol liquid -   -   no
Hydrogen gas F+   -   yes if above 7 bar
Methane gas F+   -   yes if above 7 bar
Methanol liquid F   T 0.13 no
Nitric acid (conc.) liquid -   -   yes (oxidising fluid)
Nitrogen gas -   -   no
Oleum liquid -   -   yes (reacts violently with water)
Oxygen gas -   -   no
Phenol solid -   T   no
Propane gas F+   -   yes if above 7 bar
Propylene gas F+   -   yes if above 7 bar
Sodium hydroxide solution -   -   no
Styrene liquid F 145.2 -   no
Vinyl Chloride gas F+   -   yes if above 7 bar
White oils liquid F   -   no
Xylene liquid F 139 -   no
Updated 2012-03-14