The Hale Relief Valve Spring Q-721 is a spring used in the Hale Type QG Relief Valve, which is a pressure relief valve used in fire pumps. The spring is located inside the valve and is responsible for holding the valve closed until the pressure inside the pump reaches a certain level. Once the pressure reaches the predetermined level, the spring is compressed and the valve opens, allowing the excess pressure to escape.
It is made of a high-quality spring steel and is designed to withstand the high pressures that can be generated in a fire pump. The spring is also heat-treated to improve its strength and durability.
A critical component of the Hale Type QG Relief Valve and is essential for ensuring the safe operation of the valve. If the spring fails, the valve may not open properly, which could lead to the pump overpressurizing and causing damage.
To operate the relief valve on a Hale pump, you will need to bring the pump pressure up to 150 PSI and then turn the handwheel counterclockwise until the relief valve opens. Turning the handwheel clockwise and counterclockwise at 150 PSI will cause the relief valve and control to operate. This working action frees the valve and helps to ensure proper operation.
If you need to replace the Hale Relief Valve Spring Q-721, you can purchase a new spring from a fire equipment supplier. When replacing the spring, it is important to make sure that the new spring is the correct size and type for the valve. You should also follow the instructions that come with the new spring carefully.