For the valves in operation, all valve parts should be complete and intact. The bolts on the flange and the bracket are indispensable, and the threads should be intact and no loosening is allowed. If the fastening nut on the handwheel is found to be loose, it should be tightened in time to avoid abrasion of the joint or loss of the handwheel and nameplate. If the handwheel is lost, it is not allowed to replace it with an adjustable wrench, and it should be completed in time. The packing gland is not allowed to be skewed or have no pre-tightening gap. For valves in an environment that is easily contaminated by rain, snow, dust, wind and sand, the valve stem should be equipped with a protective cover. The scale on the valve should be kept intact, accurate and clear. The lead seals, caps and pneumatic accessories of the valve should be complete and intact. The insulation jacket should have no dents or cracks.
It is not allowed to knock, stand on or support heavy objects on the valve in operation; especially non-metallic valves and cast iron valves are even more prohibited.
Maintenance of idle valves
The maintenance of idle valves should be carried out together with equipment and pipelines, and the following work should be done:
1. Clean the valve
The inner cavity of the valve should be purged and cleaned without residue and aqueous solution, and the exterior of the valve should be wiped clean without dirt, oil,
2. Align the valve parts
After the valve is missing, the east cannot be disassembled to make up the west, and the valve parts should be fully equipped to create good conditions for the next use and ensure that the valve is in good condition.
3. Anti-corrosion treatment
Take out the packing in the stuffing box to prevent galvanic corrosion of the valve stem. Apply antirust agent and grease to the valve sealing surface, valve stem, valve stem nut, machined surface and other parts according to the specific situation; the painted parts should be painted with anti-corrosion rust paint.
4. Protection
To prevent the impact of other objects, man-made handling and disassembly, if necessary, the movable parts of the valve should be fixed, and the valve should be packaged and protected.
5.regular maintenance
Valves that have been idle for a long time should be checked and maintained regularly to prevent corrosion and damage to the valve. For valves that have been idle for too long, they should be used after passing the pressure test together with equipment, devices, and pipelines.
Maintenance of electric devices
The daily maintenance work of the electric device is generally no less than once a month. The maintenance contents are:
1. The appearance is clean without dust accumulation; the device is free from contamination by steam, water and oil.
2. The electric device is well sealed, and each sealing surface and point should be complete, firm, tight, and leak-free.
3. The electric device should be well lubricated, oiled on time and as required, and the valve stem nut should be lubricated.
4. The electrical part should be in good condition, and avoid the erosion of moisture and dust; if it is damp, use a 500V megohmmeter to measure the insulation resistance between all current-carrying parts and the shell, and the value should not be lower than o. For drying.
5. The automatic switch and thermal relay should not trip, the indicator light shows correctly, and there is no failure of phase loss, short circuit or open circuit.
6. The working status of the electric device is normal, and the opening and closing are flexible.
Maintenance of pneumatic devices
The daily maintenance work of the pneumatic device is generally no less than once a month. The main contents of maintenance are:
1. The appearance is clean without dust accumulation; the device should not be contaminated by water vapor, water and oil.
2. The sealing of the pneumatic device should be good, and the sealing surfaces and points should be complete and firm, tight and undamaged.
3. The manual operating mechanism should be well lubricated and open and close flexibly.
4. The inlet and outlet gas joints of the cylinder are not allowed to be damaged; all parts of the cylinder and air piping system should be carefully inspected, and there must be no leakage that affects the performance.
5. The pipe is not allowed to be sunken, the annunciator should be in good condition, the indicator light of the annunciator should be in good condition, and the connecting thread of the pneumatic annunciator or electric annunciator should be intact without leakage.
6. The valves on the pneumatic device should be in good condition, free from leakage, open flexibly, and have smooth air flow.
7. The entire pneumatic device should be in normal working condition, open and close flexibly.
Post time: Feb-03-2023