Is it a pressure system?
Regulation 2 of PSSR defines a pressure system as one of three things that contains, or is liable to contain, a relevant fluid:
- a system made up of one or more rigid pressure vessels, with any associated pipework and protective devices;
- the pipework and protective devices that a pressure receptacle (a gas cylinder, for example) is, or is meant to be, connected to;
- a pipeline and its protective devices.
The regulations apply to pressure systems used or intended to be used at work, subject to the exceptions in Schedule 1. HSE counts 25 complete exceptions and 3 partial ones, including weapons systems and vehicle tyres. Protective devices are devices designed to protect the system against failure or to warn that failure might occur, and they include bursting discs. They are part of the system.
What counts as a relevant fluid
| Fluid | The test |
|---|---|
| Steam | At any pressure (HSE). |
| Gas or gas mixture, including compressed air | At a pressure greater than 0.5 bar above atmospheric pressure. |
| Liquid or liquid mixture | One that would have a vapour pressure greater than 0.5 bar above atmospheric pressure at its actual temperature or at 17.5 degrees Celsius. HSE gives pressurised hot water above 110 degrees Celsius as an example. |
| Dissolved gas | A gas dissolved under pressure in a solvent held in a porous substance at ambient temperature, which could be released without heat. Acetylene is the usual case. |
Common equipment, in scope or not
Use the table as a first pass. Edge cases, such as refrigeration plant, depend on the fluid and the pressure, so check the definition or ask a competent person.
| Equipment | PSSR applies? | Why |
|---|---|---|
| Steam boiler | Yes | It holds steam, which is a relevant fluid at any pressure. |
| Steam steriliser or autoclave | Yes | Steam again. A pressure vessel with its pipework and protective devices is a pressure system. |
| Air receiver | Normally yes | Compressed air above 0.5 bar over atmospheric pressure is a relevant fluid. |
| Compressed air pipework and safety valves | Yes, as part of the system | Associated pipework and protective devices belong to the pressure system they serve. |
| Portable compressor with a receiver | Normally yes | A mobile system. The owner holds the duties. |
| Hydraulic circuit | No | Hydraulic oils are not relevant fluids (HSE). |
| Gas cylinder itself | No | Pressure receptacles are excluded from the definition. The connected pipework may be covered. |
| Vehicle tyre | No | Listed in the exceptions in Schedule 1 (HSE). |
| Refrigeration or air conditioning plant | Depends | On the refrigerant and the pressure. Check against the relevant fluid tests. |
Who has which duty
Most of the duties land on the user of an installed system, meaning the employer or self-employed person who has control of its operation, and on the owner of a mobile system. A competent person has separate responsibilities.
| Regulation | The duty |
|---|---|
| 7 | Establish the safe operating limits of the system before operating it. |
| 8 | Have a written scheme for the periodic examination of the system, drawn up or certified suitable by a competent person, before operating it. |
| 9 | Make sure the parts in the scheme are examined within its intervals, and do not operate past the dates in the examination report. |
| 11 | Give the people who operate the system adequate and suitable instructions for safe operation and for emergencies. |
| 12 | Keep the system properly maintained in good repair so as to prevent danger. |
| 14 | Keep the last examination report, earlier reports where they help assess whether the system is safe, the instructions supplied with the equipment where the regulation requires them, and any agreement to postpone an examination. |
On hired or leased equipment, HSE says the user should make sure the written scheme is in place and the examination certificate is current. Schedule 2 lets duties move between supplier and user by arrangement.
What the written scheme must say
Regulation 8 sets out what the scheme covers and what it has to specify. The scheme is reviewed by a competent person at appropriate intervals, and changed in line with their recommendations.
| The scheme must | Detail |
|---|---|
| Identify the parts covered | All protective devices, every pressure vessel and pipeline where a defect may give rise to danger, and the parts of the pipework where a defect may give rise to danger. |
| Specify the nature and frequency of examination | What is examined, how, and how often. |
| Specify preparation for a safe examination | Measures beyond those the user or owner could reasonably take without specialist advice. |
| Provide for a first-use examination | Where appropriate, an examination before the system is used for the first time. |
| Be suitable | Suitable for preventing danger from the parts it includes. |
What an examination and report involve
PSSR defines an examination as a careful and critical scrutiny of the system, in or out of service as appropriate, using suitable techniques including testing where appropriate. It assesses the actual condition of the system and whether, up to the next examination, it will not cause danger when properly used and normally maintained.
After the examination the competent person makes a written report, signs and dates it, and sends it to the user or owner so that it arrives within 28 days of completion, or before the date given in the report if that is sooner. The report must:
- state which parts were examined, their condition and the results;
- specify any repairs, modifications or changes to the safe operating limits needed to prevent danger, with the date by which they must be done;
- give the date, within the limits of the scheme, after which the system must not be operated without a further examination;
- say whether the scheme is suitable or needs to change, and why.
If the competent person thinks the system will give rise to imminent danger unless repairs, modifications or changes to the operating conditions are made, regulation 10 applies. They must report that to you at once, send the enforcing authority a report with the same particulars within 14 days of the examination, and you must not operate the system, or the affected part, until the work is done.
How Fox Engineering Safety approaches it
Every examination we carry out follows the scope in your written scheme of examination. If you do not have one in place, we prepare one before the examination begins. Our competent persons then carry out a thorough examination, checking vessels, pipework, safety valves and associated protective devices, and issue a written report that details any defects found and the timescales for dealing with them.
The process runs from identifying your pressure equipment, through review of any existing scheme, in-service and out-of-service examination and testing (including non-destructive testing where deeper investigation is needed), to defect reporting and the compliance documentation. The equipment we cover is on our PSSR Inspection | Pressure Systems Safety Regulations 2000 page. To place PSSR next to LOLER and PUWER, read which statutory inspection do you need.
Sources
Duties, intervals and definitions on this page come from the legislation and HSE guidance listed here. Read the original when you need the exact wording.
- Pressure Systems Safety Regulations 2000 (PSSR) Regulations 2, 3 and 7 to 14, and Schedules 1 and 2.
- PSSR regulation 2: interpretation (pressure system, relevant fluid, examination)
- PSSR regulation 8: written scheme of examination
- PSSR regulation 9: examination in accordance with the scheme
- HSE: Pressure Systems Safety Regulations 2000 (PSSR) Source for relevant fluids, hired equipment and in-house competent persons.
- HSE approved code of practice L122: Safety of pressure systems