Q. Do all air receivers need to be inspected? What is the calculation for deciding when an air receiver needs to comply with statutory regulations?

Within the Pressure Systems Safety Regulations 2000 the question is asked: Is the pressure x volume of the pressure vessel greater than 250 bar litres? If YES - then a written scheme and inspection certificate will need to be issued to comply with the legislation.

This calculation takes the pressure rated in bars and this is multiplied by the capacity of the tank in litres. This is commonly found on a plate on the receiver.

e.g. MWP 11 bar           50 litres capacity

In this example the maximum working pressure (MWP) is 11 bar multiplied by the 50 litre capacity, which gives a rating of 550 bar litres. 1 bar is equivalent to approximately 15 psi. As a general rule air receivers with a diameter in excess of 12 inches operating at 150psi will probably need to comply with the legislation.

The other components of the air compressor set (i.e. compressor and motor) do not need a statutory inspection. If an air compressor has no receiver it does not need an inspection. Hydrovane manufacture compressors with no receivers and so are exempt from the legislation.

Q. What is the difference between an air receiver and an air compressor? Do they both need an inspection?

An air compressor has three component parts:

• driving motor
• compressor - which compresses the air
• air receiver - which is a pressure vessel which stores the compressed air

The air receiver is the only part of the air compressor unit which needs a "statutory" examination. The air compressor and driving motor do not need an inspection - but should be regularly serviced/maintained by the user.

Some air compressors only have two components - driving motor and air compressor and the delivery of compressed air is immediate and the need to store air in a pressure vessel is not required. Because these compressors do not have air receiver they do not need examination.

The term "compressor" is also used for refrigeration compressors on fridges, cold stores, freezers and air conditioning systems. Refrigeration compressors only require examination under regulations where the driving motor exceeds 25kw. The majority of commercial cold stores operate using motors well below this limit.

Q. Does the airtank on a JCB fastrack need inspecting?

If it has an air receiver which is operating in excess of 250 bar litres - YES

Q. Pressure Washers/Steam Cleaners - do they need to be inspected?

Pressure Washers do not need a statutory inspection. They operate at very high pressure (some as high as 5000 psi) but do not have a pressure vessel and therefore do not need to comply with the Pressure Systems Safety Regulations 2000. It is recommended that the electrical controls be checked regularly to ensure they are adequately insulated and this is an inspection Vulcan Inspection Services can perform if required.

Steam Cleaners, if operating using steam at any pressure, will need an examination under the Pressure Systems Regulations. There is often confusion with the definition of these types of machines where people refer to steam cleaners when they really have a pressure washer that uses hot water - but not steam. Unless steam is involved an inspection is not required.

Q. If VIS Engineer Surveyor attends a new inspection on an air receiver and a Written Scheme of Examination is required will he do it there and then?

Yes, he will complete written scheme of examination at time of initial inspection.

Under the Pressure Systems Safety Regulations 2000 all users of pressure plant must have a written scheme of examination which defines the system in operation, the safety devices present, the type and frequency of examination required etc. This written scheme is normally issued once, when the machine is new or just installed and lasts the life of the pressure vessel/boiler and is amended as necessary. At periods stated by the written scheme, a competent person (ie VIS engineer) examines the item and issues report in accordance with the written scheme. If no written scheme exists - the competent person cannot examine the item of plant and issue the report.

The written scheme will be issued at no charge to the NFUM customer. Copies of lost schemes will be printed at no extra charge (if VIS issued the original!). NFUMutual cover the cost of issue of all written schemes by a separate arrangement with VIS.

Q. How often do air receivers need to be examined?

An examination normally takes place once every twelve months. However the type and frequency of examination are defined by the written scheme.

For the majority of air receivers the first examination is a full internal thorough inspection. The next inspection, twelve months later is a working external examination and the following year another thorough. I.e. a thorough examination every two years.

With the agreement of the customer the written scheme can be amended so that both the thorough and external examination are completed at the same time and therefore only one examination takes place – every two years. Note: the price remains the same for the customer whether a one year or two year cycle of examination is maintained.

Typical annual cost of an air receiver is £25 plus VAT.

Q. Do liquid nitrogen tanks need to be inspected? Do welding bottles need an inspection?

The obligation for "inspection" of these vessels is incorporated within regulations governing the carriage of dangerous goods. Whereas for air receivers and steam boilers the user is very often the owner, for gas bottles, propane vessels, oxygen vessels etc., the responsibility rests with the supplier of the vessels.

In the majority of cases these items are rented, or purchased and replaced when empty. The user (farmer) will need to check with their supplier that the vessels supplied have been examined and found to be in a safe working condition.

Where the farmer owns the vessel - he should first check with the supplier of the gas. The supplier is deemed to be the "competent person" for these items, because they have the knowledge of storage conditions, safety devices, filling procedures etc.

Vulcan Inspection Services can examine these items - but it is not our core service and the advice we can offer is limited because our engineers are not expert in the characteristics of all gases. An inspection from VIS will very often only duplicate what the supplier has already completed.

Q. What are the implications of the new Combined Heat and Power Systems - are they statutory?

As long as the system does not fall into any of the following categories then it is excluded from the Pressure Systems Safety Regulations 2000 and therefore does NOT require a statutory examination:-

• it produces steam
• the temperature of the water in the unit is above 100° C
• any of the compressed gas expansion vessels operate in excess of 250 bar/litres

It the majority of cases it would be rare that an examination would be required however, each system is custom built to suit the client's requirements. If clarification is required as to the necessity for statutory examinations the VIS engineer can survey the premises to advise whether any of the three points apply.