Repairing tool and method for adjusting valve with valve element being provided with C-shaped ring for sealing assisting

Abstract

The invention belongs to the technical field of pneumatic valve repairing, particularly relates to a valve and provides an inspecting and repairing tool and a repairing process for the sealing surfacestate of an adjusting valve with a valve element being provided with a C-shaped sealing ring. The inspecting and repairing tool and the repairing process cover the conventional repairing problem of the sealing surfaces of the valve element with the C-shaped sealing ring and a valve seat. The repairing process comprises the following steps that firstly, the valve element and the valve seat are inspected, and repairing is prepared; secondly, the valve seat sealing surface is repaired; thirdly, a blue oil test is conducted; fourthly, the valve element sealing surface is repaired; fifthly, the valve element sealing surface and the valve seat sealing surface are inspected after grinding; and sixthly, after the valve is reassembled, an on-line leakage rate test is conducted. The sealing surfaces of the adjusting valve with the valve element being provided with the C-shaped sealing ring structure can be effectively inspected and repaired during construction and fitting, debugging and operation of a pressurized water reactor nuclear power unit; and the repairing process for the sealing surfaces is flexible, efficient, convenient, rapid and easy to control precisely, the repairing processand the principle thereof can be popularized to the situation of repairing the sealing surfaces of other adjusting valves with the valve elements being provided with the C-shaped sealing rings.

Description

technical field [0001] The invention belongs to the technical field of repairing pneumatic valves, and in particular relates to a repairing tool and a repairing method for a regulating valve with a valve core having a C-shaped ring auxiliary seal. Background technique [0002] Pneumatic control valves have many applications in pressurized water reactor nuclear power plants, especially in critical systems such as waste heat export systems. One of the pneumatic control valves has a valve core with a C-type sealing ring, and the design form of the valve core is generally balanced. figure 1 shown in. When this type of pneumatic valve is closed, the C-shaped sealing ring forms an interference fit with the cage, which is squeezed by the inner wall of the cage to produce a certain deformation. The opening position of the C-type sealing ring is generally opposite to the inlet high pressure side of the pneumatic valve. During normal operation, the high-pressure fluid flows into the...

AI Technical Summary

Problems solved by technology

During the maintenance process, the valve core and valve seat have been taken out of the valve body. When doing the blue oil test, checking the contact condition of the sealing surface by reassembling the valve body and the actuator not only consumes a lot of manpower and material resources, but also It will increase the risk of personnel and items being contaminated by radioactive media; if a pressure device such as a press is used to force the valve core to the sealing surface of the valve seat under the guidance of the valve cage, due to the lack of valve actuator rod and valve stem There is a risk of the valve stem being bent when it is connected to the guide. During the pressing process, the C-shaped sealing ring and the inner surface of the cage in contact with it may also be crushed and scratched due to problems such as poor concentricity between the valve core and the cage. risk of rubbing or deforming

In addition, when grinding the damaged sealing surface, because the angle of the valve seat and the valve core is relatively rare, it is difficult to select a grinding machine with matching angles

Another point to pay attention to is that after finding a suitable grinding machine, the coaxiality between the grinding head part of the grinding machine, the valve core and the valve seat cannot be completed by the guide rod or guide sleeve that comes with the general grinding machine. , and due to the particularity of the pneumatic control valve with a C-shaped sealing ring, its sealing surface needs to be precisely controlled during grinding, otherwise it will cause deviation of the sealing line. Based on the above reasons, it can be concluded that relying on the general stop valve grinding machine The sealing surface repair work of the pneumatic control valve with C-shaped sealing ring cannot be completed

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