Valve maintenance during operation

Update:2019-05-15      From:Tongling Wusong Valve Co.,Ltd

1, cleaning

Valve surface, stem and stem nut on the trapezoidal thread, stem nut and bracket sliding parts and gear, worm gear, worm and other parts, easy to touch a lot of dust, grease and residual media stolen goods, the valve will produce wear and corrosion. It is important to keep the outside and moving parts of the valve clean and to protect the integrity of the valve paint. Dust on valve is suitable for brush sweep and compressed air purge; Trapezoidal thread and teeth between the swab suitable for scrubbing cloth; Grease and residue on valves are suitable for steam purging, even with copper wire

Brush, until the processing surface, mating surface shows the metallic luster, paint surface shows the paint color. The trap should be responsible for special person, check at least once per shift, open the plug at the bottom of the flush valve and the trap regularly for flushing, or disassemble and flush regularly, so as not to block the valve with stolen goods.

2, valve lubrication

Good lubrication conditions are required for valve ladder threads, stem nut and bracket sliding parts, bearing parts, gears and worm wheels, worm meshing parts and other matching moving parts to reduce mutual friction and avoid mutual wear. Some parts are specially equipped with oil cup or oil nozzle. If damaged or lost in operation, repair should be completed and the oil road should be dredged. Lubricating parts should be lubricated regularly according to specific conditions. Frequently opened, high temperature valves are suitable for refueling at intervals of one week to one month; Infrequently opened, low temperature valve refueling cycle can be longer. Lubricants include oil, butter, molybdenum disulfide and graphite. High temperature valves are not suitable for oil, butter, they will melt away at high temperature, but suitable for injection of molybdenum disulfide and graphite powder. For exposed parts that need lubrication, such as trapezoidal thread, gear and other parts, if using butter and other grease, easy to be contaminated with dust, and using molybdenum disulfide and graphite powder lubrication, not easy to be contaminated with dust, lubrication effect is better than yellow. Graphite powder is not easy to apply directly, can use a little oil or water synthesis paste. Grease sealing plug valve should be lubricated according to the specified time, otherwise easy to wear and leak.

3. Valve maintenance

Valves in operation, all kinds of valves should be complete and intact. Flange and bracket bolts are indispensable, thread should be intact, do not allow loose phenomenon. If the fastening nut on the handwheel is found to be loose, it should be tightened in time to avoid wearing the joint or losing the handwheel and nameplate. If the hand wheel is lost, do not allow to replace it with a live wrench. Packing gland shall not be askew or without pretightening clearance. The valve stem shall be fitted with a protective cover for the valve in the environment susceptible to contamination by rain, snow, dust, wind, sand, etc. The scale on the valve should be kept complete, accurate and clear. Valve seal, cap, pneumatic accessories should be complete and intact. The insulation jacket should be free of dents and cracks. Do not knock, stand or support heavy objects on the valve in operation. Especially non - metallic valves and cast iron valves, more to prohibit.

The daily maintenance work of the electric device, usually not less than once a month. Maintenance contents include: clean appearance, no dust deposition: the device is free from contamination by air, water and oil. Electric device seal is good, each sealing surface, point should be complete firm, tight, no leakage. The electric device should be well lubricated and lubricated according to the regulations on time. Grease the stem nut. Electrical parts should be intact, avoid moisture and dust erosion; If damp, the insulation resistance between all current-carrying parts and the shell shall be measured with 500V megohm meter, the value of which shall not be less than 0.38 megohm, otherwise the relevant parts shall be dried. Automatic switch and thermal relay should not trip, indicator light display correctly, without phase, short circuit, break fault. The working state of the electric device is normal, flexible on and off.

Pneumatic device daily maintenance work, under normal circumstances every month and once, maintenance of the main content: clean appearance, no dust accumulation: the device is not contaminated by gas, water, oil. Pneumatic device is good sealing, sealing surface, point should be complete and firm, tight and lossless. Manual operation mechanism should be well lubricated and flexible in opening and closing. Cylinder inlet and outlet gas joints are not allowed to be damaged; All parts of the cylinder and air piping shall be carefully examined without any leakage affecting performance. No dents are allowed in the pipe. The signal should be in good condition. The indicator light of the signal should be in good condition. Pneumatic valve should be intact, no leakage, open flexible, airflow unobstructed. The whole pneumatic device should be in normal working state, flexible on and off.