J.D. Gould 1/2" NPT, 120 volt, normally closed, bronze-body solenoid valve for hot water and steam service with a maximum temperature of 356°F, a maximum hot water pressure of 125 psi and a 5 pound minimum pressure differential. J.D. Gould solenoid valves are activated by a solenoid (electromagnetic) coil, which when energized or de-energized move the core (or piston) to apply pressure against its seat. There are two operations of these valves, either normally open or normally closed. Normally open valves allow flow throughout the valve until the coil is energized to close the valve. Normally closed is sealed until the coil is energized to open the valve. Maximum operating pressure refers to the maximum difference in pressure between the inlet and outlet. Minimum pressure differential is the pressure required to open the valve.