Pressure Systems Safety Regulations 2000

PSSR pressure system thorough examinations

Written schemes of examination & statutory inspections by a competent person

PSSR governs systems that store energy under pressure, from a workshop air receiver to a steam boiler. If one fails, the consequences can be severe, so the law requires a written scheme of examination and thorough examination by a competent person. SEIS can prepare your scheme, then examine to it, and issue your report, your legal proof of compliance.

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PSSR thorough examination: pressure vessel confirmed safe to operate, examined to its written scheme by SEIS MAX MIN WITHIN SAFE LIMITS Safe to operate examined to its written scheme
Regulations 8 & 9

The scheme comes first

This is what sets PSSR apart from LOLER and PUWER. PSSR is highly prescriptive and built around a document: the written scheme of examination. Under Regulation 8 you must not operate a qualifying pressure system unless a scheme is in place, and under Regulation 9 the examination must be carried out in accordance with it.

The duty stays with you
Responsibility for having a scheme and getting the examination done is non-delegable, it sits with the user of an installed system, or the owner of a mobile one, and does not transfer to the inspection contractor.

In practice, compliance follows three steps:

  • A scheme is drawn up or certified
    A competent person identifies which parts fall in scope and sets out how and how often they must be examined. We can prepare yours, or certify an existing one.
  • The system is examined to the scheme
    A competent person carries out the thorough examination at the intervals the scheme sets, checking vessels, pipework and protective devices.
  • Findings are reported and acted on
    You receive a written report of the examination. Any defect affecting safe operation must be put right before the system goes back into service.
What a written scheme sets out
The minimum a compliant WSE must cover
  • Which parts are in scope
    The vessels, pipework and protective devices the scheme covers, identified individually.
  • The nature of each examination
    What type of examination each item needs, including any testing where appropriate.
  • How often it is examined
    The maximum interval between examinations for each item, set by the competent person.
  • How to prepare it safely
    The preparatory work needed so the system can be examined safely, such as isolation and depressurising.
  • Whether to examine before first use
    Where appropriate, the scheme states that an examination is needed before the system is first used.
Schemes follow the HSE Approved Code of Practice L122. We prepare or certify yours.
Does it apply to you?

Systems with a relevant fluid

PSSR applies to pressure systems that contain a relevant fluid, the term the regulations use to define what is in scope. The breakdown alongside shows what counts. If your system holds one of these, PSSR is likely to apply.

The scope is broad and not just heavy industry: a commercial coffee machine that generates steam is caught, as is a workshop air compressor. Protective devices such as safety valves are covered too, where they protect a qualifying system.

The 250 bar-litres threshold
For non-steam systems, a written scheme is generally needed once pressure multiplied by volume exceeds 250 bar-litres. Steam systems are caught at any pressure. Borderline? We calculate it and advise, so you have a documented decision either way.
What counts as a relevant fluid
The four categories defined under PSSR 2000
Steam
At any pressure, no threshold applies. Boilers, autoclaves and steam receivers are all caught.
Gas above 0.5 bar
Any gas, or gas-liquid mixture, at a pressure greater than 0.5 bar above atmospheric, such as compressed air.
Pressurised hot water
Water heated above 110°C under pressure, as found in some heating and process systems.
Gas dissolved under pressure
A gas dissolved in a solvent under pressure, the classic example being acetylene cylinders.
Not sure if your system qualifies? We assess it against the PSSR definitions for you.
The examination

How the examination works

Once your scheme is in place, the examination itself is a careful, critical scrutiny of the system by a competent person, using suitable techniques and testing where needed, to confirm it is safe to keep operating. In practice it usually falls into two types, shown alongside.

Examinations are timed to the intervals your scheme sets, often 12 months for many items, though the competent person sets each one by item. Where it helps, we time examinations to coincide with your planned maintenance, since the system may need to be stripped down for access.

If there is imminent danger
Where the competent person finds a defect that means the system cannot safely continue at its current limits, the law requires them to report it and notify the enforcing authority. We make those findings clear, with the action needed.
Two types of examination
Both carried out by a competent person, to your scheme
Out-of-serviceShut down
The system is isolated, depressurised and prepared, so the surveyor can examine vessels internally and externally for corrosion, wear and defects, along with pipework and protective devices.
In-serviceRunning
A working examination with the system under normal operating conditions, checking that protective devices and controls function correctly while it is live.
Your scheme decides which type each item needs, and how often. We carry out both.
What we examine

Pressure equipment we examine

From a single air receiver to a full steam plant, our engineer surveyors examine the pressure vessels, pipework and protective devices that make up your system, against your written scheme.

Not sure whether your equipment falls under PSSR, or whether you already need a scheme? Tell us what you run and we will confirm what the regulations require, prepare a scheme if you need one, and set the examination intervals.

Ask about your system
Pressure equipment we examine
A selection of systems covered under PSSR 2000
Air receivers
Pressure vessels
Steam boilers
Autoclaves
Expansion vessels
Steam receivers
Plus compressors, refrigeration plant, jacketed pans and the pipework & safety valves that serve them.
Areas we cover

PSSR examinations across our coverage area

We work nationwide, with established local engineer surveyors across our coverage area. Choose your county to find pssr examinations in your nearest town.

Cambridgeshire2 towns
PSSR examinations in Cambridge PSSR examinations in Peterborough
County Durham1 town
PSSR examinations in Darlington
Derbyshire1 town
PSSR examinations in Derby
Lincolnshire3 towns
PSSR examinations in Grimsby PSSR examinations in Lincoln PSSR examinations in Scunthorpe
Nottinghamshire3 towns
PSSR examinations in Mansfield PSSR examinations in Nottingham PSSR examinations in Retford
Tyne and Wear1 town
PSSR examinations in Newcastle
Yorkshire15 towns
PSSR examinations in Bradford PSSR examinations in Castleford PSSR examinations in Doncaster PSSR examinations in Halifax PSSR examinations in Harrogate PSSR examinations in Huddersfield PSSR examinations in Hull PSSR examinations in Keighley PSSR examinations in Leeds PSSR examinations in Pontefract PSSR examinations in Rotherham PSSR examinations in Selby PSSR examinations in Sheffield PSSR examinations in Wakefield PSSR examinations in York
Due a PSSR examination?
Talk to an engineer surveyor about your pressure system, get your written scheme and examination handled, wherever you are in the UK.
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PSSR FAQs

Common questions about PSSR examinations

Clear answers to the questions duty-holders ask most about pressure system safety and written schemes of examination. If yours isn’t here, our engineer surveyors are happy to help.

What is a written scheme of examination?

A written scheme of examination (WSE) is a legally required document that sets out which parts of a pressure system must be examined, the nature of each examination, how often it must be done, and how to prepare the system safely. It must be drawn up or certified by a competent person and be in place before the system is operated. Under PSSR you cannot legally run a qualifying pressure system without one.

Does PSSR apply to my equipment?

PSSR applies to pressure systems containing a relevant fluid: steam at any pressure; a gas or gas-liquid mixture above 0.5 bar above atmospheric; pressurised hot water above 110°C; or a gas dissolved under pressure. For non-steam systems, a written scheme is generally needed once pressure multiplied by volume exceeds 250 bar-litres. Steam systems are caught at any pressure. If you are unsure, we assess your equipment against the definitions.

How often does a pressure system need examining?

PSSR sets no single fixed interval. The interval is determined for each item by the competent person and recorded in your written scheme of examination, based on the equipment, its contents and how it is used. In practice many items are examined every 12 months, but the scheme is what governs the actual frequency.

Who can carry out a PSSR examination?

A competent person, with the combination of training, skills, experience and knowledge needed to draw up or certify the written scheme and to examine the system against it. For most businesses this is an independent inspection body. SEIS engineer surveyors provide both the scheme and the examination as an independent service.

What is the difference between PSSR and LOLER or PUWER?

PSSR is more prescriptive. Where LOLER applies a fixed 6 or 12-month rule to lifting equipment and PUWER uses risk-based intervals for work equipment, PSSR centres on a written scheme of examination that must be in place before use, with the competent person setting the intervals for pressure equipment. The common thread is that all three require examination by a competent person.

Can SEIS write our scheme as well as examine it?

Yes. We can prepare a written scheme of examination for new or existing equipment, or review and certify a scheme you already have, then carry out the thorough examinations to it and manage the schedule, so the whole PSSR duty is covered in one place.

Is PSSR examination a legal requirement?

Yes. If you operate a qualifying pressure system at work, PSSR places legal duties on you to have a written scheme of examination and to be examined to it by a competent person. The duties are enforced by the Health and Safety Executive, and the responsibility stays with the user or owner, not the inspection contractor.