PRECAUTIONS FOR FORGED STEEL VALVES

Forged Steel Valves often ignore the problem of grease injection. After the grease injection gun is refueled, the operator selects the valve and the grease injection connection method for the low temperature shut-off valve, and then performs the grease injection operation. There are two situations in the forged steel gate valve: on the one hand, the amount of grease injection is small and the grease injection is insufficient, and the sealing surface wears quickly due to the lack of lubricant. On the other hand, excessive grease injection results in waste. The reason is that there is no precise calculation of the sealing capacity of different valves according to the valve type category. The sealing capacity can be calculated according to the valve size and type, and then a reasonable amount of grease can be injected.

　　Forged steel gate valves often ignore pressure issues. During the grease injection operation, the grease injection pressure regularly changes with peaks and valleys. The pressure is too low, the seal leaks or the safety valve fails, the pressure is too high, the grease injection port is blocked by the valve manufacturer, the sealing inner grease is hardened, or the sealing ring is locked with the valve ball and valve plate. Usually, when the grease injection pressure is too low, the injected grease mostly flows into the bottom of the valve cavity, which usually occurs in small gate valves. And the pressure of the grease injection flow control valve is too high. On the one hand, check the insulation gate valve and check the grease injection nozzle. If the grease remote control float valve hole is blocked, it will be determined that the spring is closed and the wrench is fully opened. On the other hand, the plunger stop valve is grease. To harden, use cleaning fluid to soften the failed sealant repeatedly and inject new grease to replace it. In addition, the sealing type and sealing material also affect the grease injection pressure. Different sealing forms have different grease injection pressures. Generally, the grease injection pressure of hard seals is higher than that of soft seals.

　　Forged steel globe valve pay attention to the problem that the valve is in the switch position. The ball valve is generally in the open position during maintenance, and in special cases, it is selected to be closed for maintenance. Other valves can not be regarded as an open positions. The forged steel globe valve must be closed during maintenance to ensure that the grease fills the sealing groove along the sealing ring. If it is opened, the sealing grease will fall directly into the flow channel or valve cavity, causing waste. When the valve is greased, the effect of grease injection is often ignored. During the grease injection operation, the pressure, grease injection volume, and switch position are all normal. However, in order to ensure the grease injection effect of the valve, sometimes it is necessary to open or close the valve, check the lubrication effect, and confirm that the surface of the valve ball or gate plate is evenly lubricated.

　　The forged steel check valve should pay attention to the problem of valve body blowdown and wire plug pressure relief. After the valve pressing test, the gas and water in the valve cavity of the sealing cavity will increase due to the increase of the ambient temperature. When injecting grease, it is necessary to discharge the sewage and release the pressure first, so as to facilitate the smooth progress of the grease injection. The air and moisture in the sealed cavity are fully replaced after grease injection. The valve cavity pressure is released in time, which also ensures the safety of the valve. After the grease injection, be sure to tighten the drain and pressure relief plugs to prevent accidents. When injecting grease, pay attention to the problem of uniform grease. During normal grease injection, the grease discharge hole closest to the grease injection port will discharge grease first, then to the low point, and finally to the high point, and the grease will be discharged one by one. If it does not follow the rules or there is no fat, it proves that there is a blockage, and it should be cleaned in time.

　　For the forged steel extended end gate valve, it is necessary to observe the problem that the valve diameter is flush with the sealing ring seat. For example, for a ball valve, if there is interference in the opening position, adjust the opening position limiter inward to confirm that the diameter is straight and then lock. Adjusting the limit should not only pursue the opening or closing position but consider the whole. If the opening position is flush and the closing position is not in place, the valve will not close tightly. In the same way, if the adjustment of the closed position is in place, the corresponding adjustment of the open position should also be considered. Make sure the valve has a right angle of travel. After grease injection, be sure to seal the grease injection port. To avoid the entry of impurities or the oxidation of lipids at the grease injection port, the cover should be coated with anti-rust grease to avoid rusting. for the next operation.

　　The sealing surface of the high-pressure forged steel gate valve is a plane or a conical surface, and the opening and closing parts are plug-shaped discs, which move linearly along the centerline of the fluid. The movement form of the valve stem includes a lifting rod type (the valve stem rises and falls, and the handwheel does not rise and fall), and there is also a lifting rotary rod type (the handwheel rotates and lifts together with the valve rod, and the nut is arranged on the valve body). The bellows globe valve is only suitable for fully open and fully closed, no adjustment and throttling are allowed.

　　Forged steel cryogenic valves should be considered for specific problems in the sequential transportation of oil products in the future. Given the different qualities of diesel and gasoline, the scour and disintegration ability of gasoline should be considered. In the future valve operation, when encountering gasoline section operations, the grease should be replenished in time to prevent the occurrence of wear. When injecting grease, do not neglect the grease injection at the valve stem. There are sliding bushings or packings on the valve shaft, which also need to be kept lubricated to reduce the frictional resistance during operation. If lubrication cannot be ensured, the torque will increase the wear parts during electric operation, and the switch will be laborious during manual operation.

　　Some ball valves are marked with arrows. If there is no English FIOW handwriting, it is the direction of action of the sealing seat, not as a reference for the flow direction of the medium, and the direction of the valve self-leakage is opposite. Typically, double-seated ball valves have bidirectional flow