Technical Articles
Six Common Faults and Elimination Method of Safety Valve
Posted: 04/22/2015 16:26:21  Hits: 419
1. The disc of safety valve doesn’t return back after the discharge.
This is mainly because of the bent stem or the disc is out of position, so you should assemble it again.
2. The leakage problem of safety valve
In normal working pressure, due to the dirt, there is leakage between disc and seat sealing surface. So, you can open and close the valve for several times by lifting the wrench to wash the dirt out; if the sealing surface is damaged, you can grind it before or after the turning according to the damage degree; if there is dislocation between stem and core, it is because of the bent or oblique stem or the deflection between lever and fulcrum, in this case, you need to reassemble it or change a new one; if the elasticity of a spring is reducing or losing, you should change the spring or readjust the pressure.
3. The safety valve doesn’t open when reaching the prescribed pressure
The season for this situation is inaccurate constant pressure. So, you should readjust the spring compressed length or hammer position; if the disc and valve seat stick together, you can do manual release or dewatering test on safety valve regularly; if the lever is stuck or the hammer is moved, you should readjust the position of hammer to let the lever move easily.
4. The pressure continues to rise after the discharge
The main reason is that the discharge capacity of the selected safety valve is less than the safety discharge capacity of the equipment, so you need to choose an appropriate safety valve; if the midline of stem is crooked or the spring is rusted, the disc will not open to the original height, so, you need to reassemble the stem or change a new spring; if the area of exhaust pipe is small, you need to change a new one which meets the discharge area.
5. The chatter and vibration of safety valve
This is mainly because the rigidity of a spring is too big, you need to change a spring with proper rigidity; if it is caused by the big resistance from pipe, then you need to decrease the resistance.
6. The safety valve opens before reaching the required pressure
This is mainly because of the inaccurate level pressure or decreased elasticity, so you need to tighten the screw appropriately or change the spring.
Six Common Faults and Elimination Method of Safety Valve