G100 Safety Relief Valves

G100 Bronze high lift safety relief valves.

Stainless Steel Full Lift Safety Relief valve – side outlet discharge with or without test lever. These valves are used to prevent excess pressure build up in systems providing maximum flow rates. Suitable for use on steam, liquids and gases.

Size Range:

  • Stainless Steel: DN15 to DN25 (½” to 1″)

Pressure Range:

  • 0.3 Bar.g (4 PSI) TO 27.59 Bar.g (400 PSI)

Pipe Connections:

  • Female x female.
  • Inlet: Threaded ‘G’ BSP Male to BS EN ISO 228/BS 2779.
  • Outlet: Threaded ‘Rp’ Parallel Female to BS 21/BS EN 10226/ISO 7.
  • Alternative thread standards, i.e. taper or NPT are available upon request.
  • Flanged connections also available. Most flange standards can be accommodated.

Features and Benefits:

  • Gresswell Valves are quality assurance approved to BS EN ISO 9001: 2008 and manufactured in accordance with BS EN ISO 4126-1 & BS6759.
  • Full Cat IV PED approval.
  • The G100 range of valves are ideal for handling compressible material but it must be noted… they are not suitable for liquids.
  • Clear operating and maintenance instructions are supplied with each despatch.
  • See data sheets for Discharge Capacities.

Flow Substance:





Steam boiler, pipeline and vessel protection.

Compressor, pipeline and reciever protection


All Gresswell Relief Valves are given a hydraulic seat tightness test before leaving the factory and all valves are supplied pre-set. Special tests or witness testing can be arranged at extra cost.