Valve repair and installation-2

Release time:

2024-03-22

What are the general procedures for valve maintenance? Answer: the general procedures for valve maintenance are as follows.

1) Clean the surface outside the valve door, and clean it with compressed air or kerosene.

2) Check and record the valve nameplate and other marks.

3) Disassemble all parts of the valve in sequence.

4) Clean the parts with kerosene.

5) Check the parts for defects. Check the strength of the valve body by hydraulic test; check the fit between the valve seat and the valve body as well as between the closing part and the sealing ring, and carry out the tightness test; check the thread wear of the valve rod and the valve rod bushing; check the sealing ring of the closing part and the valve body; check the surface of the valve cover, remove the burrs; check the joint surface of the flange.

6) Repair the valve body. Repair the defects by welding and replace the sealing ring or overlay the sealing surface; carry out the tightness test on the valve body and the new sealing ring, as well as the joint between the overlay metal and the valve body; repair the flange joint surface; grind the sealing surface.

7) Repair closure. Repair welding defects or build-up welding of sealing ring, turning or grinding of sealing surface.

8) Repair the packing chamber. Check and trim the packing chamber, trim the gland and the cone at the bottom of the packing chamber.

9) Replace parts that cannot be repaired.

10) Reassemble the valve.

11) Carry out the overall hydraulic test of the valve.

12) The valve shall be painted and marked according to the original record.

How is the valve maintained?

Answer: the maintenance requirements of the valve are as follows.

Do not use long lever or spanner wheel when closing or opening the valve.

The valve rod thread often rubs with the valve rod nut, and a certain amount of oil shall be kept at the screw to play a lubricating role, so as to ensure the free movement and flexibility of the valve rod. When the valve is mechanically driven, add lubricating oil to the gearbox in time; for the valve that does not open and close frequently, turn the hand wheel regularly, and add lubricant to the stem thread to prevent it from seizing.

If the valve is opened for a long time, there may be dirt on the sealing surface; when it is closed, the valve can be closed slightly first, and then opened a little, so that the dirt can be washed away by using the high-speed flow medium, and then closed tightly.

For the valve installed outdoors, a protective sleeve shall be set on the valve rod to protect it from rain, snow and dust. The valve shall be cleaned and inspected frequently to keep all parts of the valve clean and complete. Do not place heavy objects on the valve, let alone stand on the valve.

Before opening the steam valve, the condensate in the system shall be removed first, and then the valve shall be opened slowly to avoid steam water impact; when the valve is fully opened, the hand shall be turned back a little.

The spare valve shall be placed in a dry place indoors, and the interface shall be sealed with wax paperboard or plug to prevent dirt from entering.