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To: Directors of Environmental Health/ Chief Environmental Health Officers of London, Metropolitan, District and Unitary Authorities and Chief Executives of County Councils.

For the attention of: Environmental Services / Trading Standards / Fire Authorities / Other

This circular gives advice to local authority enforcement officers

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ROTARY VANE AIR COMPRESSORS - FITTING OF SAFETY VALVES TO AIR RECEIVERS

INTRODUCTION

1 Safety valves should be fitted on air receivers which are charged from rotary vane air compressors.

BACKGROUND

2 Although normally a rotary vane type compressor is used without an air receiver there are instances where a user has combined a rotary compressor with an air receiver to satisfy a particular requirement.

3 Although most rotary air compressors are fitted with a safety valve to safeguard the oil separation vessel, this valve alone is not sufficient to protect the air receiver. Rotary compressors are fitted with non-return valves at the air delivery point which effectively isolate the oil separation chamber safety valve from the air receiver. A safety valve on the compressor alone cannot be relied on to protect the air receiver as well.

ADVICE TO LA ENFORCEMENT OFFICERS

4 Installations of this type should have a safety valve fitted to the air receiver or on a manifold directly attached to the air receiver with no intervening stop-valve.

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