ball check valve,double union check valve 1.Size:1/2",3/4 ... JIS,DIN,BS OR BSPT,NPT ball check valve,double union check valve 1.Description1).Name: pvc union2).size: ... DIN,BS OR NPT,BSPT5).Working condition:1.0Mpa6).end connector: socket7).pressure:PN108).Application: water supply,water draining, ... to fluidity 5)economical and environmental 3. componentsunion connector, o-ring, union body and union nut