PSSR 2000 · Pressure systems

Pressure vessel examination under PSSR

Independent examination of your pressure vessel under a Written Scheme of Examination, by a competent person under PSSR.

A pressure vessel is any closed container holding a fluid at a pressure well above the air around it, and the energy stored inside does not care what process the vessel serves. If it holds a relevant fluid above the threshold, PSSR puts it on a written scheme and a competent examination, whatever it is called.

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  • Independent and impartial
  • Competent engineer surveyors
  • Reports issued promptly
Any relevant fluidIn scope above 250 bar litres, or steam at any pressure
Written schemeExamined to a certified written scheme of examination
Certified reportA written report of examination, within 28 days
Inside and outCorrosion and cracking the surface cannot show
Pressure equipment we examine

Why your pressure vessel needs PSSR examination

Pressure vessel is the broad term for the receivers, separators, calorifiers, buffer and surge vessels, knock-out pots and process vessels that hold a fluid under pressure across industry. Whatever the label, the principle is the same: a sealed shell stores energy, and if it weakens and lets go that energy is released all at once. The examination is concerned with the integrity of that shell and the devices that protect it.

A vessel comes under PSSR where it holds a relevant fluid above the threshold, that is a gas or other relevant fluid where pressure times internal volume exceeds 250 bar litres, or steam at any pressure. Regulation 8 then requires a written scheme of examination before the vessel is used, and it is examined to the scheme, inside and out, with its relief valve and gauge tested. We carry out the examination independently and report on condition.

Shell and plates
Dished ends
Welds and seams
Nozzles and branches
Relief valve
Pressure gauge
Manway and openings
Supports and nameplate
How it works

How we examine your pressure vessel

A competent engineer surveyor examines the vessel inside and out, because the corrosion, pitting and cracking that matter are usually on surfaces a casual look never reaches. The shell, ends, welds and nozzles are examined for wastage and cracking, the relief valve is removed and tested so it lifts at the set pressure, the gauge is checked for accuracy, and the safe working pressure is confirmed.

  • 1

    Get in touch

    Tell us the vessel, what it holds, its pressure and volume, and whether a written scheme is in place.

  • 2

    On-site examination

    A competent engineer surveyor examines the vessel inside and out and tests the relief valve, to the scheme.

  • 3

    Your report

    You receive a written report of examination, any defects and timescales set out, within the statutory window.

Why businesses choose SEIS

  • Independent and impartial: we examine the vessel, we do not supply or service it
  • Competent engineer surveyors used to process and pressure plant and PSSR
  • Internal and external examination, not a quick look at the outside
  • Certified reports issued promptly, the next examination date flagged
What we examine

Pressure vessel: what a thorough examination covers

Shell, ends and welds

The shell, dished ends and the welded seams examined inside and out for corrosion, pitting, wastage and cracking, the pressure boundary the whole vessel depends on.

Nozzles and branches

The nozzles, branches and their welds checked for cracking and corrosion, the connections where stress concentrates and leaks begin.

Relief valve

The relief valve removed and tested so it lifts at the set pressure, set at or below the vessel's rating, the protection against over-pressure.

Internal surfaces

The internal surfaces examined for the corrosion, scale and erosion that thin the vessel out of sight and that no external inspection can find.

Manway and openings

The manway and inspection openings checked for condition and sealing, the access that lets the inside be examined properly in the first place.

Nameplate and safe working pressure

The nameplate and marked safe working pressure confirmed, so the vessel is operated within the limits the scheme and the examination are built around.

Scheme and certification

How it works, and what you receive

A pressure vessel comes under PSSR where it holds a relevant fluid above the threshold, so under Regulation 8 it must have a written scheme of examination, drawn up or certified by a competent person, before it is used. It is then examined to the intervals the scheme sets, which for many vessels falls in the range of around two years, longer for well maintained vessels and shorter for those that deteriorate quickly, in line with industry guidance such as SAFed PSG 01. After each examination you receive a written report on the condition of the vessel and its protective devices, with any actions and timescales, issued within twenty-eight days.

Step oneA Written Scheme of Examination, certified before use
To schemeExamined to the intervals the scheme sets
28 daysA written report, issued within the statutory window
IndependentWe examine it, we do not supply it

You receive a report on the condition of the system and its safety devices, with any actions and timescales set out clearly.

The price follows your equipment, not a rate card: see what drives a PSSR examination quote.

Full statutory cover

Part of our full PSSR inspection service

Pressure vessel is one of the many kinds of equipment we cover. We inspect the full range, across every sector, as an independent provider, one item or a whole site, anywhere in the UK.

See our full PSSR inspection service
Other services

Other statutory inspections we carry out

Many sites run more than one regime. We can examine all of it, under one independent provider.

LOLER inspectionThorough examination and certification of lifting equipment and accessories. PUWER inspectionInspection of work equipment against the five PUWER duties, with a written record. LEV testingLEV thorough examination and test of your extraction systems.
PSSR FAQs

Pressure vessel examination: common questions

Does my pressure vessel need a PSSR examination?
It does where it holds a relevant fluid above the threshold. That means a gas or other relevant fluid where pressure times internal volume exceeds 250 bar litres, or steam at any pressure. Such a vessel must not be used without a written scheme of examination. You can read the duty in the HSE guidance on the Pressure Systems Safety Regulations.
Do I need a written scheme of examination, or a certificate?
A written scheme. Regulation 8 requires a written scheme of examination, drawn up or certified by a competent person, before the vessel is used, and the examination against it produces a certified written report. Our guide to PSSR explains the scheme and what it must contain.
How do I work out whether my vessel is in scope?
Multiply the maximum operating pressure in bar by the internal volume in litres. If the result is more than 250 bar litres and the contents are a relevant fluid, the vessel is in scope. Steam is in scope at any pressure regardless of the figure. If you are unsure, we can advise.
How often should a pressure vessel be examined?
To the intervals the written scheme sets, on the duty and condition. Many vessels are examined around every two years, with well maintained vessels going longer and those that deteriorate quickly examined more often. The competent person sets and reviews the interval.
What does the examination cover?
The shell, dished ends, welds and nozzles inside and out, the relief valve tested to confirm it lifts, the pressure gauge checked for accuracy, the manway and openings, and the nameplate and safe working pressure.
Is my vessel covered by PSSR or PUWER?
PSSR, where it is above the threshold or holds steam. Below the threshold the written scheme duty falls away, but the vessel is still work equipment to be maintained and inspected under PUWER, and your insurer may still require an examination. A PUWER inspection does not replace a PSSR examination.
Who is competent to examine a pressure vessel?
A competent person with the training, skills, experience and knowledge for the vessel and its contents, independent of its operation. Our engineer surveyors examine pressure vessels of many kinds and report to the written scheme.
Do you examine pressure vessels across the UK?
Yes. Our engineer surveyors travel to factories, process plants and workshops nationwide, a single vessel or a whole system. Call 0330 043 8191 to arrange a visit around your shutdown.

Is your pressure vessel due an examination?

Talk to an engineer surveyor, get a quote and book your inspection anywhere in the UK.

0330 043 8191 Request a quote