Union connection to boiler for easier installation and flexible positioning;Includes an automatic air vent to release trapped air from the system;Integrated ball valve isolates vent for service without obstructing the PRV;3/4" FIP port accommodates PRV provided with your boiler (or sold separately);3/4" close nipple provided for convenient adaptations to your specific boiler equipment;Plugged 3/4" FIP port for optional low water cut-off device;Dual-sided & plugged 1/4" FIP ports for flexible gauge installation;Saves 60 Minutes;Replaces 10 Components;Eliminates 9 Leak Paths;This valve is actuated by a blowout proof stem;Double O-ring Stem Seals