​​A4.1 General​

All pressure or vacuum systems that are bought in by others to use on STFC sites should be checked before use, to ensure that they do not present a hazard when in use.

A4.2 Measures for pressure systems

The manager responsible for the area where a contractor or visitor will use a pressure system that they have bought to site should ensure that:

1. the system has been designed and tested in accordance with the PSSR2000: and
2. it will only be operated by trained competent people: and for non-exempt systems: and
3. has been thoroughly examined in accordance with its written scheme of examination.

It is unfortunate that some contractors and visitors will be unable to satisfy these criteria. In such circumstances, and only for exempt pressure systems that do not require statutory inspection, the managers of such areas may put in place an assurance process where they assess the safety of such systems, and put in place a safe way of working with it on STFC sites. Such a process should:

• Start with the request for information from the system owner. The information requested should include, but not necessarily be limited to:
  
  • the unique identification mark of the system. i.e. its serial number,
  • a full description of the proposed work that the system will be used for,
  • a set of full engineering drawings giving key dimensions and materials used in its construction,
  • test certificates for the materials used in construction. Including any fasteners,
  • manufacturing QA documents,
  • any calculations done to prove the system's robustness. FEA plots are not sufficient,
  • any evidence of Pressure Tests done on the system,
  • the Design Pressure, Working Pressure and Test Pressure; and
  • the Design Code the system has been made to. If this is not the case the justification for the deviation.
• Include a stage where an STFC mechanical engineer checks the system over when it arrives on site:
• Include a pressure test at an appropriate multiple of the design pressure - dependent on the design code used: and
• Conclude with the system being given an STFC identification mark and being signed off for use on STFC sites by the local Pressure/vacuum System Nominated Engineer. The "signing off" should include the date after which the system cannot be used on site with re-inspection.

A4.3 Measures for vacuum systems

Any manager of the area where a contractor or visitor will use a vacuum system that they have bought to site should ensure that:

1. The system is examined by a Pressure/Vacuum System Nominated Engineer to ensure it is safe to use, and
2. It will only be operated by trained competent people, and
3. It cannot be pressurised in any way above atmospheric pressure; and
4. It will not undergo major modifications while on site without being examined by the appropriate Pressure/Vacuum System Nominated engineer.

In the event that a vacuum system is set up so it can be pressurised above atmospheric pressure, pressure relief device(s) must be fitted.