Spring Loaded Pressure Vacuum Relief Valve

About the spring-loaded relief valve

Motherwell’s ATEX-approved spring-loaded pressure/vacuum relief valves provide tank protection for bulk storage tanks, including LNG tanks and fixed-roof tanks with floating covers. They minimise evaporation loss and unwanted emissions and prevent excessive pressure or vacuum that could unbalance the system or damage the storage vessel.

These direct-acting valves are also known as breather valves, conservation vents or safety vents. Valves are built to customer requirements and set at the manufacturer’s factory in St Helens.

Configurations and options

Principle of operation

The cast body is flanged for connection to the storage tank. A weatherhood protects the pressure exhaust port, and a mesh cover prevents foreign matter entering valves vented to atmosphere. Piped-away versions are also available.

Both the pressure and vacuum sides incorporate a pallet and diaphragm assembly resting on an O-ring seal to prevent leakage. The O-ring can be removed and the seat machined optically flat for a metal-to-metal seating arrangement.

When pressure or vacuum increases, the pallet and diaphragm lift to allow air or gas to flow.

Benefits

• High gas flow from a compact valve size.
• A wide range of pressure and vacuum settings for tank protection with minimum gas loss.
• Valve sizing service to assist optimum performance and cost specification.
• Multiple configuration options for venting to and from pipes or atmosphere.

Configure CNC380SS — Spring Loaded