Maintenance Method Of Valve In Operation

- Mar 27, 2020-

The purpose of maintenance during valve operation is to ensure that the valve is in a clean, well lubricated, complete and normal operation state.

1、 Valve cleaning

The surface of the valve, the trapezoidal thread on the valve stem and the valve stem nut, the sliding part of the valve stem nut and the bracket, and the gear, worm and other parts are easy to accumulate a lot of dust. Oil pollution, media residue and other spoils will cause wear and corrosion to the valve. Therefore, it is very important to keep the outside and moving parts of the valve clean and protect the integrity of the valve paint. The dust on the valve is suitable for brush sweeping and compressed air sweeping; the dirt between trapezoidal thread and teeth is suitable for cleaning with rags; the oil stain and medium residue on the valve are suitable for steam sweeping, and even brush with copper wire until the processing surface and matching surface show metallic luster and the paint surface shows the true color. The drain valve shall be in the charge of a specially assigned person. Each shift shall check at least once. The plug at the bottom of the flushing valve and the drain valve shall be opened regularly for flushing, or the drain valve shall be disassembled and flushed regularly to prevent the valve from being blocked by dirt.

2、 Lubrication of valves

The trapezoidal thread of the valve, the sliding part of the stem nut and the bracket, the bearing part, the meshing part of the gear and worm wheel, the worm and other matching moving parts all need good lubrication conditions to reduce mutual friction and avoid mutual wear. Some parts are specially equipped with oil cup or oil nozzle. If they are damaged or lost in operation, they shall be repaired and matched, and the oil circuit shall be dredged.

The lubricating parts shall be oiled regularly according to the specific conditions. The frequently opened valve with high temperature is suitable for filling once every week to a month. The valve with low temperature can have a longer filling period. Lubricants include oil, butter, molybdenum disulfide and graphite. High temperature valve is not suitable for oil and butter, which will be lost due to high temperature melting, but suitable for molybdenum disulfide injection and graphite powder wiping. For exposed parts requiring lubrication, such as trapezoidal thread, gear and other parts, if grease and other grease are used for electric control valve, it is easy to be contaminated with dust, but if molybdenum disulfide and graphite powder are used for lubrication, it is not easy to be contaminated with dust, and the lubrication effect is better than that of butter. Graphite powder is not easy to apply directly, it can be used with a little oil or water.

The plug valve with oil filling seal shall be filled with oil according to the specified time, otherwise it is easy to wear and leak.


3、 Valve maintenance

All kinds of valves in operation shall be complete and intact. The bolts on the flange and bracket are indispensable, and the thread shall be intact without looseness. Tighten the fastening nut on the hand wheel in time in case of looseness, so as to avoid wearing the connection or losing the hand wheel and nameplate. If the handwheel is lost, it is not allowed to replace it with a monkey wrench, and it should be equipped in time. The packing gland shall not be skewed or pre tightened. For the pneumatic control valve in the environment easy to be contaminated by rain, snow, dust, sand and other pollutants, the valve rod shall be installed with a protective cover. The scale on the valve shall be complete, accurate and clear. The lead seal, cap and pneumatic accessories of the valve shall be complete and intact. The insulation jacket shall be free of dents and cracks.

It is not allowed to knock, stand or support heavy objects on the valve in operation, especially non-metal valve and cast iron valve, which is more prohibited. Stainless steel multistage centrifugal pump

CDL / CDLF is a non self-priming multi-stage centrifugal pump with standard motor installed. The motor shaft is directly connected with the pump shaft through the pump head with a coupling, and the pressure cylinder and overflow parts are fixed between the pump head and the water inlet and outlet section by the pull rod bolts, and the water inlet and outlet of the pump are in the same straight line at the pump bottom; the pump can be equipped with intelligent protector according to needs to effectively protect the dry running, phase loss, overload, etc. of the pump.