Hydraulic Flat Face Quick Release Couplings. 1/4″ to 1 1/4″ BSP. Flat face couplings are used in a variety of applications due to the higher operating pressures and leak free performance. Manufactured to the ISO 16028 standard. With working pressures from 400 bar to 315. Standard ISO 16028. Valve Type: Flat Face. Maximum Operating Pressure …