3/4" FNPT 30 PSI Brass Pressure Relief Valve with PTFE Tape

3/4" FNPT Brass Pressure Relief Valve

This 30 PSI brass valve protects hot-water boilers and hydronic heating systems by opening automatically when pressure exceeds the factory-set limit. It ships with a roll of PTFE thread sealing tape so installers can seal the 3/4 inch female NPT connections without extra trips to the supply house. The one-piece brass body resists corrosion and wear, making it a durable replacement for ageing relief valves in closed-loop heating circuits. It is not intended for potable-water supply lines.

Thermals Noise and Power Draw

The valve operates passively with no electrical supply, so it adds no heat, noise or power draw to the mechanical room. Its brass construction conducts system temperature without degrading, and the PTFE tape helps maintain a leak-free seal through normal thermal cycling. Because the device is purely mechanical, there are no motors, fans or electronics to fail or consume energy.

Behaviour Under Sustained Load

When system pressure reaches 30 PSI the valve lifts and discharges excess fluid until pressure falls back below the set point, then reseats automatically. The fixed calibration cannot be adjusted in the field, so the relief pressure remains constant over repeated cycles. Brass internals resist scale build-up that could otherwise cause sticking during prolonged over-pressure events, and the included PTFE tape ensures the inlet and outlet joints stay tight through extended service.