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Spring Loaded Pressure Vacuum Relief Valve

Spring Loaded Pressure Vacuum Relief Valve

Direct acting pressure / vacuum spring loaded relief valve (also known as breather valve, conservation vent, or safety vent) is a special type of relief valve which is specifically designed for tank protection.

Motherwell range of spring loaded relief valves includes pressure relief only, vacuum relief only and combined pressure/vacuum relief valves and are Ideal for Liquid Nitrogen Gas Tanks (LNG Tanks), all our Spring Loaded Relief Valves are available with flanged outlets or vented to atmosphere. The pressure outlet can either vent to atmospher or can be piped away with a flange fitted, The Vacuum inlet can also be configured to vent in from either atmosphere or it can have a flange fitted

The Spring loaded relief valve is used extensively on bulk storage tanks, including fixed roof tanks with floating covers and Liquid Nitrogen Gas Tanks (LNG Tanks), to minimise evaporation loss and unwanted emissions. The spring loaded relief valves prevent the build up of excessive pressure or vacuum which can unbalance the system or damage the storage vessel. The relief valves are all built to customer requirements and all set at our factory in St Helens

The spring loaded relief valve has a cast body which is flanged for connection to the storage tank. A weather hood protects the pressure exhaust port and a mesh cover is fitted to prevent the ingress of foreign matter for valves vented to atmosphere. Piped-away versions are also available throughout the range.

Both the pressure and vacuum sides of the relief valve incorporate a pallet and diaphragm assembly which rest on an ‘O’ ring seal to prevent leakage. This ‘O’ ring can be removed and the seat machined optically flat, producing a metal to metal seating arrangement if required. The weight of the pallet pushes the diaphragm against the seat to keep it closed. When the pressure or the vacuum increases, the pallet and diaphragm lifts and air/gas is allowed to flow.

Benefits of the spring loaded relief valve

All our breather valves can be configured as spring loaded relief valves on either the pressure or vacuum in all the options we offer.

ATEX Approved Breather Valves

Pressure Vacuum Relief Valve PVRV (CNC380, CNC383, CNC385 & CNC386)Pressure Vacuum Relief Valve PVRV (CNC380, CNC383, CNC385 & CNC386)Pressure Only Relief Valves - PRV (CNC381 & CNC384)Pressure Only Relief Valves - PRV (CNC381 & CNC384)Vacuum Relief Valve (CNC382 & CNC387)Vacuum Relief Valve (CNC382 & CNC387)