Each individual system must be assessed to determine the frequency and nature of thorough examinations.
Our engineering team is able to draw up Written Schemes of Examination and complete thorough examinations on a wide range of pressure plants including:
- Steam Boilers
- Air Receivers
- Bulk Powder Tankers (Excluding hazardous substances)
- Traction Engines
My pressure system contains a relevant fluid, so do I need a Written Scheme of Examination and regular examination?
The size of a pressure system determines which parts of the regulations apply. The requirement for a Written Scheme of Examination (Regulation 8) and examination in accordance with the Written Scheme applies to systems containing a vessel that either:
- Contains steam at any pressure.
- Has a pressure x volume product of 250bl or more.
To calculate this, multiply the operating pressure (in bar) by the vessel capacity (in Litres). For example, for a compressed air system containing a 50 Litre air receiver (the vessel), and operating at 10 bar:
10 bar x 50 Litres = 500bl
This system would require both a Written Scheme of Examination and regular examination as it exceeds the 250bl limit.
The HSE provide a flow chart on page 9 of the PSSR ACOP that can help you determine which part of the regulations apply to your system.
What is a Written Scheme of Examination?
A Written Scheme of Examination is a document containing information about the items of plant or equipment that form a pressure system. It details which components require regular examination, and at what frequency.
Under the Pressure System Safety Regulations (PSSR), the user of an installed system and the owner of a mobile system have a duty not to allow the system to be used until the have a Written Scheme of Examination in place. This should cover:
- protective devices
- pressure vessels
- parts which, if they fail, may give rise to danger
PSSR refers to an 'installed' system and 'a mobile' system. What is the difference?
A mobile system is one that can be easily moved from place to place, eg an air compressor that is taken from site to site. An installed system is one that is not a mobile system, eg a steam boiler.