Pressure Systems Safety: Written Schemes and Examination for Compliance

Pressure systems safety is governed in the UK by the Pressure Systems Safety Regulations (PSSR), which require that systems containing pressurized fluids, steam, compressed air, refrigeration, are safe, and specifically that they operate under a written scheme of examination and are examined by a competent person before the scheme’s deadlines. Pressure systems fail energetically, which is why the regime is prescriptive and the evidence trail non-negotiable. Educational overview, not legal advice.

The written scheme of examination

The heart of PSSR is the written scheme: a document, drawn up or certified by a competent person, that specifies which parts of the system must be examined, how, and at what intervals. Nothing within scope may operate outside a valid scheme, and examinations must happen before the scheme’s dates. The scheme is the plant’s bespoke examination plan, and keeping to its deadlines is the core compliance duty.

What the regime requires

• Safe design and installation, with proper documentation.
• A written scheme of examination for systems that can store significant energy.
• Examination by a competent person in accordance with the scheme, before the due dates.
• Operation within safe limits, with functioning protective devices (relief valves and trips).
• Maintenance to keep the system safe, and records retained.

Protective devices deserve emphasis: a relief valve is a credited safeguard whose failure is invisible until the day it matters, which is why relief valve testing and, after repairs, hydrostatic testing sit at the center of a pressure program, exactly the barrier-integrity logic of safety instrumented systems.

A worked example: the examination that was two weeks late

A plant’s written scheme sets a 26-month examination interval on a steam receiver. The examination slips two weeks past the scheme date because nobody was tracking it against a calendar the operators could see. In compliance terms the system was operating outside its scheme, a breach regardless of the vessel’s actual condition. When the examination finally runs, the competent person finds early shell thinning that would have been flagged on time, now closer to an action threshold. Two failures compounded: a missed deadline and a real degradation that the deadline existed to catch. A scheduled, visible examination due-date, escalating before it lapsed, prevents both. Under PSSR, the examination date is a hard line, not a target.

The compliance evidence

PSSR compliance is demonstrated by documents: the written scheme, reports of examination completed before their deadlines, defect actions tracked to closure within the competent person’s timescales, and protective-device test records. The recurring failure mode is administrative, an examination missed because no system flagged it, not usually a plant that intended to run unsafe equipment.

Where Fabrico fits

Fabrico does not draw up written schemes or perform examinations, competent persons do that, and it does not certify pressure systems. What Fabrico owns is the deadline and evidence discipline the regulation lives on: every scheme-covered item as an asset with its examination due dates as preventive schedules that escalate before they lapse, examination reports and protective-device tests attached to the asset history, defects tracked to closure within timescales, and the record ready when the enforcing authority or insurer asks. A missed examination becomes conspicuous long before it becomes a breach. EU-built, with EU data residency.

Frequently Asked Questions

What pressure systems need a written scheme of examination?

Broadly, systems containing a relevant fluid at pressure that can store significant energy, steam at any pressure, and compressed or liquefied gas above threshold conditions. The precise scope is a competent-person judgment; small, low-energy systems may fall outside, but steam systems are firmly in.

Who is the competent person under PSSR?

Someone with the necessary knowledge and experience to draw up or certify the written scheme and to carry out examinations, in practice often an engineer surveyor from an inspection body or insurer. Competence must match the system’s complexity and hazard.

What happens if an examination deadline is missed?

Operating a covered system past its written-scheme examination date is a breach, independent of the equipment’s actual condition. The system should be examined before continued use, and the gap addressed. This is precisely why examination due-dates belong in a system that flags them before they lapse.

Want every pressure-system examination tracked, evidenced, and never late? Book a Fabrico demo to see statutory examination discipline run through a field-ready CMMS.