The maintenance of valves is an important measure to ensure their long-term stable operation and extend their service life. Here are some key steps to note for valve maintenance:
1.Preservation and maintenance
a.Orderly storage: Valves should be stored in categories, with small valves placed on shelves and large valves neatly arranged on the ground to avoid disorderly stacking and damage caused by flange connection surfaces coming into contact with the ground.
b.Cleaning and Protection：
(1)Seal the inlet and outlet of the valve with wax paper or plastic sheets to prevent dirt from entering.
(2)Apply anti rust oil to the machined surface that can rust in the atmosphere for protection.
(3)Valves placed outdoors should be covered with oil felt or cloth to prevent dust and rain.
c.Regular inspection:
(1)For valves that are not used for a long time, asbestos packing should be removed to avoid chemical corrosion.
(2)The valves newly added to the warehouse should be checked for rainwater or dirt and wiped clean in a timely manner.
2.Usage and maintenance.
a.Keep clean: Regularly keep the valve clean and lubricate the transmission threads regularly.
b.Correct operation:
(1)The valve stem thread needs to be coated with lubricant (such as yellow dry oil, molybdenum disulfide, or graphite powder) to reduce wear.
(2)Valves that are not frequently opened or closed should also have their handwheel turned regularly to prevent the valve stem threads from biting.
(3)Outdoor valves require protective sleeves for the valve stem to prevent rain, snow, dust, and rust.
c.Inspection and maintenance
(1).Regularly check the sealing performance and operational flexibility of the valve to ensure no leakage or blockage.
(2).Check whether the connecting components (such as bolts and nuts) are loose or damaged, and tighten or replace them in a timely manner.
d.Packing maintenance
(1).Packing is the key to valve sealing and requires regular inspection and timely replacement of failed packing.
(2).After the valve is installed in the pipeline, if there is leakage, the packing gland nut should be tightened, but it should not be tightened all at once to avoid losing elasticity.
3.Lubrication and grease injection
a.grease injection volume and pressure:
(1)When injecting grease, the amount should be accurately calculated based on the sealing capacity of the valve type to avoid excessive or insufficient grease.
(2)The grease injection pressure needs to be lost. If it is too high, it may block the grease injection port, and if it is too low, the sealing effect will be poor.
b.Injection timing:
(1)During the use of valves, due to the loss and drying of lubricating grease, regular replenishment is required.
(2)Especially during the process of valve opening and closing, the lubrication condition of the transmission parts should be checked in a timely manner.
4.Special maintenance for different valves
(1)When fully open, the operating pressure loss of the medium is minimized, making it suitable for situations that do not require frequent opening and closing.
(2)Not suitable for use as a regulator or throttle to avoid damaging the sealing surface.
(1)After opening, there is no contact between the valve seat and the sealing surface of the valve disc, and the wear of the sealing surface is small.
(2)Attention should be paid to the flow direction of the medium during installation, generally from bottom to top.
c.ball valve
(1)The structure is simple, the operation is convenient, and it is suitable for situations with fast opening and closing.
(2)When in use, only fully open or fully closed, not used to regulate flow.