This valve is used for the high building fire fighting system. When the pressure in the water supply pipeline is over the one set for pressure relieving, the pressure relieving valve is opened to prevent both pipeline and equipment from getting damaged due to excessive pressure. Used as a pressure relieving valve and also a pressure holding valve. Application: Used in the Fire protection system, petroleum refining, petrochemical and chemical manufacturing, natural gas processing and power generation industries, the term relief valve is associated with the pressure safety issue