A gas pressure regulator is a mechanical device which attaches to the delivery valve on the cylinder. The regulator is designed to work at the maximum pressure for a given cylinder and regulate the output- delivery- to a lower pressure for use. They are equipped with safety devices to limit the release rate of gas if a fault occurs. There are two pressure gauges – one on the cylinder side to indicate the contents pressure and the other on the delivery side. There is an adjustment control to set the delivery pressure to the desired level.

Regulators must be subject to regular inspection and replaced every 5 year for non-corrosive gases. The body of the regulator is stamped for date of manufacture. More frequent replacement cycles are required for corrosive gases - see guidance.

Where a regulator performs the function of 'flow control' and is not regarded as the primary Protective Device, then it will not be regarded as Primary Regualtor and hence will not subject to the 5 year replacement requirement. Further guidance on this decision can be found here.

Regulators are designed for a specific type of gas – the correct regulator delivering the correct pressure range must be used on the cylinder.

Gas regulators fitted to two differing cylinders