CEJN 10-564-6605 Nipple with pressure release valve, 3/4"-16UNF fem NBR - SAE 1/2" O-ring CEJN Series 564 is a Flat-Face quick-connect nipple with a built-in pressure eliminator. The nipple is according to and exceeds the demands in the ISO 16028 Standard for low- and medium-pressure hydraulic applications. The Flat-Face design minimizes spillage during connection and disconnection. The pressure eliminator allows for connection with residual/trapped pressure on the nipple side. The nipple Series 564 connects with couplings in Series 565, Series 566 and Series 562.