The maintenance principles during valve operation are as follows:
1. Keep the outside of the valve and the moving parts clean to protect the integrity of the valve paint. The surface of the valve, the trapezoidal thread on the stem and stem nut, the sliding part of the stem nut and the bracket, the gears, worm gears, etc. are prone to deposit dust, oil and media debris, causing wear and corrosion to the valve. Therefore, the valve should be kept clean at all times. The general dust on the valve is suitable for brush sweeping and compressed air blowing. It can even be brushed with a copper wire brush until the working surface and the mating surface show metallic luster, and the paint surface shows the original color of the paint. Steam traps should be specially staffed and inspected at least once per shift; periodically open the flush valve and regularly flush the bottom plug of the steam trap, or periodically disassemble and rinse to prevent dirt from clogging the valve.
2. Maintain the lubrication of the valve. The valve trapezoidal thread, the sliding part of the stem nut and the bracket, the bearing position, the meshing part of the gear and the worm wheel and other matching moving parts need good lubrication conditions, reducing the mutual friction and avoid mutual abrasion. For parts without oil cup or nozzle, which are easily damaged or lost during operation, the lubrication system should be repaired and the oil circuit should be clarified.
The lubrication part should be refueled regularly according to the specific conditions. Frequently opened, high temperature valves are suitable for refueling once a week to one month; valves that do not open frequently and are not for high temperature may have a longer refueling cycle. Lubricants are engine oil, butter, molybdenum disulfide and graphite. Engine oil is not suitable for high temperature valves; butter is also not suitable, they will be lost due to high temperature melting. The high temperature valve is suitable for adding molybdenum disulfide and wiping graphite powder. Lubricating parts exposed outside, such as trapezoidal threads, parts between gears, are easy to be contaminated with dust once they are lubricated with butter. While lubricated with molybdenum disulfide and graphite powder, the parts are not easy to contaminate dust and the lubrication effect is better than butter. Graphite powder is not easy to apply directly. It can be used with a little oil or water to make a paste.
The oil-filled plug valve should be filled with oil according to the specified time, otherwise it will be easy to wear and leak.
3. Keep the two pieces complete and in good condition. The bolts of the flange and bracket should be complete and full screwed, and no looseness is allowed. If the fastening nut on the handwheel is loose, tighten it in time to avoid wearing the joint or losing the handwheel. After the handwheel is lost, it is not allowed to replace the handwheel with a wrench. The handwheel should be equipped in time. The packing pressure difference does not allow for skewing or pre-tightening clearance. In an environment that is easily contaminated by dirt such as rain, snow, dust, the valve stem should be fitted with a protective cover. The gauge on the valve should be kept intact and accurate. The seals, caps and pneumatic accessories of the valve should be complete and intact. The insulation jacket should be free from dents and cracks.
In addition, it is not allowed to knock, support heavy objects or stand on the valve to avoid soiling the valve and damaging the valve, in particular, for non-metallic mesh doors and cast iron valves.
Maintain routine maintenance of the electric device. The maintenance of the electric device is generally not less than once a month. The maintenance contents are as follows: the appearance should be clean, no dust and dirt deposition; the device is not affected by soda water and oil; the sealing surface and the point should be firm and tight. No leakage phenomenon. The lubrication part should be refueled according to the regulations, while the valve yoke nut should be greased; the electrical part should be in good condition, no phase fault; the automatic switch and the thermal relay should not trip, and the indicator light is correct.