Thermostatic Control Valve Application

FPE Valve Operation Overview
FPE thermostatic control valves can be used in one of three different applications: as a diverting valve, mixing valve, or 2-way valve. The action of the thermostat, with its sensing bulb located in the A-port fluid stream, determines the flow path in any application. The thermostats are factory set and enclosed inside the valve so there are no parameters or temperatures to set, and no wires to connect…just pipe into your system, and confidently walk away.


Diverting Valve Application
In a diverting application, the valve directs fluid flow from the inlet port to one of two outlet ports based on the temperature of the fluid. The fluid inlet port for a diverting valve is the A-port. The cold fluid will exit thru the B-port and the hot fluid will exit thru the C-port.

Upon start-up, and when the temperature of the fluid entering the valve is approximately 10°F or more below the set-point of the valve, the thermostat will be in the fully closed position and the fluid will exit the valve thru the B-port.

As the fluid temperature rises and approaches the set-point, the thermostat will start to open, and a small portion of the flow will be diverted to the C-port.

As the temperature continues to rise above the set-point, the thermostat will open further causing more fluid to exit the C-port while restricting flow thru the B-port.

Once the fluid reaches a temperature 10°F above the set-point, the thermostat will be in the fully open position and the fluid will exit the valve thru the C-port.

Typical diverting applications are engine coolant and lube oil cooling circuits.

 
Mixing Valve Application
In a mixing application, the valve will mix two different temperature fluids to the set-point temperature of the valve. For the inlet ports of the valve, the B-port is connected to the hot fluid supply and the C port is connected to the cold fluid supply. The mixed temperature fluid will exit the valve thru the A-port.

Upon start-up, and when the temperature of the fluid entering the B-port of the valve is approximately 10°F or more below the set-point of the valve, the thermostat will be in the fully closed position. At these temperatures the fluid will enter the valve thru the B-port and exit the A-port.

As the fluid temperature rises and approaches the set-point, the thermostat will start to open, and allow a small portion of the cold fluid from the C-port to enter and mix with the hot fluid from the B-port. As the temperature continues to rise above the set-point, the thermostat will modulate between the open and closed positions to allow more or less of the cold fluid to enter the C-port to satisfy the set-point requirements of the mixed outlet fluid.

Typical mixing applications are engine boiler pool heating circuits.