Pressure valves in this category include pressure relief valves, boiler feed valves and pressure reducing valves from Taco, Zurn, Honeywell and Matco-Norca.
Pressure Valve Types and Applications
Pressure Relief Valves To protect the system components from excessive pressure created by expansion of hot water, a pressure relief valve is used. A typical hot water heating or plumbing system requires a diaphragm type expansion tank, which accommodates the expanded hot water. When hot water volume exceeds the tanks’ capacity and the pressure created by hot water exceeds the threshold pre-set value of the pressure relief valve, it opens, releasing the excess water.
Pressure Reducing Valves Most of the pressure reducing valves sold at PexUniverse.com are adjustable. They feature a knob or other mechanism which allows to regulate the flow-through water pressure. This feature allows to adapt an external water supply to the pressure specifics of the heating system.
Boiler Feed Valves A typical hydronic heating system has an external water supply, which automatically refills the system when its’ pressure drops below the settings of the boiler feed valve. Since the external water supply pressure (i.e. domestic water pressure) almost always exceeds that of the hydronic system, boiler feed valve acts as a pressure reducing valve. The valve is often coupled with a pressure relief valve which performs the functions described above.
Pressure Bypass Valves In a heating system with zone valves or actuator valves (such as on a radiant heating manifold), the valves have a slower reaction time then that of the circulator pump. When the circulator starts and the valves are not fully open, the pump generates excess pressure inside the system, shortening the lifetime of itself and other system components. A pressure bypass valve, such as Taco 3196 series, helps to bypass the excessive pressure until the zone valve(s) fully open.