Analysis of Causes of Seal Leakage of High Temperature Control Valve

The regulating valve is an important component in the hydraulic system. Its main function is to keep the outlet pressure of the system at a level lower than the inlet pressure, keeping the outlet pressure of the system stable, and the outlet pressure of the system is not affected by the inlet pressure and flow fluctuations; However, once the leakage of sealing surface occurs in the high-temperature control valve, it will not only affect the normal production, but also cause the loss of hydraulic oil and pollute the environment. In the marine hydraulic system, the high-temperature control valve as the main control element, the importance of sealing is not to be underestimated. .

In the term of a high-temperature control valve theory, a control valve has both static and dynamic characteristics, and therefore it affects the success or failure of the entire control loop. The static characteristic or gain term is the flow characteristic of the valve and it depends on the size of the valve, the combination of the valve plug and valve seat, the type of actuator, the positioner of the valve, the pressure in front of the valve and behind the valve, and the nature of the fluid.

The high temperature signal output from the high temperature control valve can directly drive a diaphragm-type actuator or piston actuator to actuate the valve. In this case, the energy required to determine the valve position is provided by the compressed air. The compressed air should be dried in outdoor equipment to prevent freezing and should be cleaned and filtered. When a high-temperature control valve is used in conjunction with an electric regulator, an electropneumatic valve positioner or an electric-to-air converter can be used. The air supply system for compressed air can be considered in the same way as a conditioning system for full temperature.

1. Analysis of static sealing faults in regulating valves.

After researching and analyzing with related experts, it was found that the seal between the connecting sleeve and the valve body of the regulating valve mainly depends on the O-ring between the connecting sleeve and the inner wall of the valve body for circumferential sealing. Once the sealing is effective, the outer seal leaks. It is inevitable.

2, to solve the problem of high temperature control valve sealing measures.

(1) Reduce the friction between the O-ring of the regulating valve and the sealing surface.

(2) Guarantee the compression of the O-ring of the sealing valve seal.

(3) Improve the sealing valve sealing surface quality.

(4) increase the sealing valve face seal.

More knowledge: high temperature control valve / stainless steel butterfly valve / pneumatic ball valve /