Do I need a written scheme of examination?
A written scheme is likely to be required before operating a qualifying pressure system when component failure could give rise to danger. Product labels such as compressor, boiler or refrigeration plant are useful clues, but the legal decision turns on the defined system and relevant fluid.
Check my situationUse a fluid–pressure–danger screen
Establish whether there is a pressure system, whether it contains steam, gas above the relevant pressure threshold, high-temperature pressurised water or another relevant fluid, and whether failure of a covered part could give rise to danger. Missing data is a reason to investigate, not a no answer.
- Check maximum and normal pressure rather than relying on the current gauge reading.
- Include safety valves and other protective devices, plus relevant vessels and pipework.
- Check who is the user of an installed system or owner of a mobile system and whether a supplier has assumed any duties in writing.
What to do next: Collect the equipment plate data, drawings and safe limits, then ask a competent person to confirm scope. If a new qualifying system has no suitable scheme and examination, resolve that before putting it into operation.
Strong indicators
Compressed-air receivers, steam boilers, autoclaves, refrigeration plant, pressure process vessels and commercial steam boilers frequently justify a PSSR check. The final scope can include more than the obvious vessel.
- Steam at any pressure
- Compressed or liquefied gas above 0.5 bar above atmosphere
- Pressurised hot water above 110°C
- Associated protective devices and safety-critical pipework
Why pressure alone is not the whole answer
PSSR includes definitions, exceptions and divisions of responsibility that cannot be reduced to a single gauge threshold. Hydraulic systems, transportable receptacles, pipelines and installed systems can follow different routes or other legislation.
The finder therefore identifies clear indicators and uncertainties. It does not certify that a system is included or exempt.
What to assemble for a decision
Provide the competent person with equipment schedules, pressure and temperature data, fluids, capacities, manufacturer information, drawings, protective devices, operating history, modifications and existing inspection documents.
Incomplete information may require a site inventory before a scheme can be priced or certified. Put that discovery work explicitly into the quotation rather than assuming it is free.