1.Check the valve line on the valve plug and the valve seat, it should be in good condition, and there is no defect that affects the sealing effect. If there is a slight defect, the grinding method should be used to eliminate the grinding method; if there is a deep blow or pit, it should be repaired by lathe processing; if the valve line is seriously damaged and cannot be repaired, the spare parts should be exchanged.
2.Check that the stem seal section should be clean.
3.There should be no oxides and other impurities deposited and adhered around the window of the inspection sleeve. If it is, it should be cleaned.
4.Check the sealing surface between the valve line and the valve seat on the valve seat, which should be smooth and complete, without any dents, blisters and penetrating scratches that affect the sealing.
5.Check that the sealing surface between the bonnet and the valve body is complete.
6.Check the inside of the valve body, especially the inner wall on the outlet side, and there should be no obvious blow damage and thinning.
7.Check the packing in the packing chamber and replace it if it is damaged.
8.All sealing surfaces should be cleaned.