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Safe Use Of Pressure Systems

Systems must be:

  • suitable for the purpose;
  • constructed of suitable materials;
  • installed correctly; and
  • be capable of being operated safely.

Installers must ensure that the system is safe and protective devices work properly.

Where pressurised apparatus has been set up in a laboratory and is itself the subject of a research experiment, it is recognised that it is not always reasonably practicable to apply most of the Regulations to the equipment. In the case of such research projects, the individual circumstances and duration of the project will dictate whether it is reasonably practicable to comply with the Regulations. Anyone relying on this exception MUST be able to justify their reasons for non-compliance and any failure to take the basic precautions required under the Regulations to prevent risk of injury from system failure. Departments must develop their own risk assessment for the apparatus which should include any safe operating limits (pressures, temperatures etc.) and develop (and disseminate) safe working instructions and training in the use of the pressure system. Note that the exception does not apply to any commercially available pressure system introduced as part of the laboratory / research experiment. For these items, the full regulations will apply.

Most pressure systems will otherwise require a Written Scheme of Examination (WSE) to be drawn up by a 'competent person'. Accreditation to BS EN ISO/IEC 17020:20125 is an indication of the competence of an inspection department, organisation or self-employed 'competent person'. The written scheme of examination (WSE) is a document that identifies the parts of a pressure system required to be examined by a competent person. It typically includes all protective devices, such as safety valves; most pressure vessels; and certain pipework, where the failure of which could give rise to danger. For each part of the system included in the scheme, the WSE will state how often examination should take place, and the nature of the required examination. Certain plant items will also require the competent person to be involved during repair or modification and this will also be explained within the scheme. The WSE has to be certified by a competent person.

The scheme will specify what needs to be examined (pressure vessels, pipework, safety devices etc) and at what intervals. Co-ordination of this is carried out by the Purchasing Officer

Departments must arrange to have examinations carried out by a competent person in accordance with the Written Scheme and ensure the system is safe for inspection. The statutory examination is normally conducted by the University Insurance company (Zurich), and the results reported via CRIMSON. . It should be noted that where the pressure equipment needs to be dismantled, or taken apart to observe the pressure system, this examination will need to be coordinated and carried out with the equipment maintenance/servicing company, such that the system can be re-assembled properly post inspection. The University Insurance company may well 'fail' equipment that cannot be inspected, if their statutory examination cannot be coordinated. Departments must ensure that these items are identified and that appropriate coordination takes place when the visits by Zurich are scheduled.

Operators must be trained and adequately supervised. Instructions must be provided to ensure systems are operated within safe limits and include emergency procedures.

Suitable protective devices (safety valves etc) must be fitted and:

  • function correctly;
  • be adjusted to their correct settings;
  • discharge to a safe place; and
  • be kept in good working order.
  • Warning lights/alarms must be noticeable. Protection devices must never be overridden, bypassed or otherwise rendered ineffective.

Pressure systems must be properly maintained by competent persons. Users should be alert for signs of wear or damage and report potentially unsafe conditions immediately.

The Written Scheme of Examination, the latest examination reports and manufacturer’s records supplied with the equipment must be kept.

Organisations renting, leasing or hiring equipment are responsible for:

  • the Written Scheme of Examination;
  • examinations in accordance with the scheme;
  • training and manuals; and
  • maintenance and records.
  • Users must obtain written agreement from the owner as to these duties.

Pressure vessels must be clearly marked with:

  • the manufacture’s name;
  • a serial number;
  • date of manufacture;
  • the standard to which the vessel was built;
  • maximum and minimum (if other than atmospheric) design pressures; and
  • the design temperature.
  • This information must not be concealed or defaced.


TPRs are vessels (e.g. gas cylinders) having a volume not exceeding 1000 litres (or 500 litres if seamless) or transportable assemblies of containers, each having a volume <150 litres.

The Carriage of Dangerous Goods (Classified, Packaging and Labelling) and Use of Transportable Pressure Receptacles Regulations cover the design, manufacture, repair, marking and filling etc of TPRs.