Compressed Air

Under the Pressure Systems Safety Regulations 2000 (PSSR) the user/owner is responsible to ensure there is a written scheme of examination in place before your compressed air equipment is in operation. This applies to any system with a vessel that has a pressure X volume greater than 250 bar litres, contains a relevant fluid and operates above 0.5 bar should have a written scheme of examination in place. You should also periodically undertake compressor inspections by a competent person to ensure you remain compliant.

Users/owners of pressure vessels are required to demonstrate that they know the safe operating limits of their system, and that the system is safe under those conditions. Compressor testing and air receiver inspections to meet PSSR 2000 will include external and internal examinations at intervals as instructed by the competent person.

It is also worth noting that compliance to pressure testing regulations will not be met by your annual service, this is a separate inspection and all written schemes need to be undertaken by a competent person with the written scheme of examination signed off by an IEng or CEng qualified engineer.

Below is an example list of compressed air products that would require a written scheme:

  • Mobile compressors
  • Vessel or air receiver
  • Pneumatic machinery
  • Automation equipment and conveyors

Mandate Systems specialise in written schemes of examination covering the whole of the UK, we have highly skilled directly employed engineer surveyors and can typically deliver your scheme within 48 hours of site attendance. Our schemes are signed off by our in-house Chartered Engineer and available on our customer online portal for immediate viewing. Having your scheme in place will ensure compliance for HSE inspections.

We offer free impartial advice on compressor examinations and all elements of pressure testing, if you would like to check if you need to have a written scheme of examination in place…call us.

Frequently Asked Questions

Mandate Systems is packed with guidance and advice on Pressure Systems Safety, but we have also provided answers to some frequently asked questions. Please let us know if there is a question you would like the answer to that isn’t listed here.

A WSE is a legal document that is required on most pressure equipment under the Pressure System Safety Regulations 2000 (PSSR). The WSE lists the components within a system, examinable items and the frequency these should be examined. This is all noted in your WSE.

It is a common misconception that new equipment does not require a WSE, however this is incorrect. All equipment that falls under the regulations must have a WSE in place before it is used for the first time, regardless of age.

Any person deemed competent to create a WSE document can do so if they have the relevant experience and knowledge, however the WSE document must be certified by either an Incorporated or Chartered Engineer, depending on the system size (usually this will require Chartered Engineer qualification sign off).

Under the Pressure Systems Safety Regulations you must have a WSE in place prior to the use of the system. This system will include a rigid vessel and a relevant fluid, mainly gas (carbon dioxide, nitrogen, argon, steam among others), with a pressure at 0.5 bar or above excluding steam, which is at any pressure.

The competent person determines the frequency of examination by item, and notes this in your written scheme. It is most common for the items to be examinable every 12 months.

This is a legal requirement under the Pressure Systems Safety Regulations 2000 (PSSR) and is enforced by the Health and Safety Executive (HSE) and Local Authority. If the regulations are not adhered to, unlimited fines or prosecution from HSE are a possibility.

Equipment capable of operating at 250 bar litres or above, or steam at any pressure, will fall under the regulations. To work this out multiply the maximum working pressure X vessel volume – e.g. 10.0 bar x 50 litre = 500 bar litre.

The WSE is the obligation of the owner so hire units should be covered by the owner of the equipment, unless otherwise agreed.

The written scheme should be completed by an independent body so that impartiality can be proven. This can be completed by a service provider as long as they are competent in this field and impartiality can be evidenced. It is paramount to note however, that the person certifying the WSE must also have the relevant qualifications (e.g. Incorporated or Chartered Engineer).