Model SP158B, fully engineered freeze protection bleed valve.
Model SP158B, fully engineered freeze protection valve is constructed of a one piece brass body, and supplied with a removable cartridge for easy cleaning and maintenance. Automatic thermal actuator bleed valve opens when internal water temperature falls below 35° F (1.7° C) and closes completely when the water climbs back to 42° F (5.6° C). 1/2" NPTF inlet and outlet.