1,Short pattern,small volume and light weight. 2,Both soft and metallic seats can be chosen according to different working conditions,all with perfect sealing effect. 3,With a small starting pressure,discs can be fully opened under a very small pressure difference. 4,Quick close and small water hammer effect. 5,Can be installed both in horizontal and vertical position. 6,The variety of body materials are optional.Gasket can be chosen according to customer;s requirement and be used in different pressure,temperture and working condition.