The Watts brass controllable check valve CC 55.1 is a fully integrated EA check valve unit with special features, focussed on easy verification and time savings. Exchanging or cleaning a dirty or damaged check valve cartridge is now a matter of simple handling. For the DN 15 en DN 20 besides the isolation valve on the inlet side, a pressure gauge and a drain valve, a second isolation valve has been integrated into the outlet side. It prevents the drinking water installation downstream the CC 55.1 from draining during maintenance and replacement. The DN 25 with a 28 mm compression fitting has been developed specially for installation in front of a fire reel. There is already an isolation valve in front of the fire reel. For this reason the CC 55.1 DN 25 has only been given an isolation valve at the upstream side. Depending on your application, you might also order the basic model CC, a brass check valve without pressure gauge and drain valve.