How often is it best to overhaul the valve?

Valve maintenance cycle and general procedures

In order for the valve to operate normally for a long time, it needs to be regularly repaired and maintained. The maintenance cycle of valves and pipeline accessories is generally determined by the maintenance of the equipment used by the unit. For example, the overhaul of oil refinery equipment is once a year, and the valve is also repaired at this time. Now, with the advancement of science and technology, the application of new technologies and the improvement of maintenance methods, many oil refining and chemical enterprises have undergone valve overhaul from once a year to once every two years or once every three years, and the longest even reaches every 5 years. Second, the corresponding valve maintenance should be carried out at the same time.

Valve maintenance is generally divided into what three categories?

Valve maintenance is generally divided into three categories, as follows.

Minor repairs: clean the oil nozzle and oil cup, replace the packing, clean the valve stem and its threads, remove the debris in the valve, tighten and replace the bolts, and match the handwheel.

Intermediate repairs: including minor repairs, dismantling and cleaning parts, repairing valve bodies, grinding seals, straightening valve stems, etc.

Overhaul: Including medium repair items, replacement of valve stem, repair of brackets, replacement of springs and seals, etc.

Generally, valves repaired indoors should be disassembled and inspected and gaskets should be replaced.

The maintenance of valves is generally more common in small and medium-sized repairs.

What are the general procedures of valve maintenance?

a. Blow the outer surface of the valve with compressed air.

b. Check and note the markings on the valve.

c. Disassemble all the valves.

d. Clean the parts with kerosene.

e. Check the parts for defects. Check the strength of the valve body with the hydraulic test; check the fit between the valve seat and the valve body and the closing part and the sealing ring, and carry out the sealing test; check the thread wear of the valve stem and the valve stem nut; check the sealing of the closing part and the valve body ring; check the surface of the bonnet to eliminate burrs; check the joint surface of the flange.

f. Repair the valve body. Weld repair defects and replace sealing ring or surfacing sealing ring; conduct sealing test on the valve body and the newly replaced sealing ring, as well as the connection between the surfacing metal and the valve body; trim the flange joint surface; grind the sealing surface.

g. Repair closures. Welding repair defects or surfacing sealing surface; car polishing or grinding sealing surface.

h. Repair the stuffing chamber. Inspect and trim packing chamber; trim gland and taper at bottom of packing chamber.

i. Replace the parts that cannot be repaired.

j. Reassemble the valve.

k. Carry out the hydraulic test of the valve as a whole.

l. The valve is painted and marked according to the original record.

Complete solutions for Industrial valves