Precautions For Forged Steel Valves

The problem of grease injection amount is often ignored in forged steel valves. After the grease gun is refueled, the operator selects the valve and grease injection connection method, and then performs grease injection. However, there are two situations in forged steel gate valves: on the one hand, the amount of grease injection is small and insufficient, and the sealing surface wears faster due to lack of lubricant. On the other hand, excessive grease injection causes waste. It is because the sealing capacity of different valves is not accurately calculated according to the valve type category. The sealing capacity can be calculated according to the valve size and category, and then the appropriate amount of grease can be reasonably injected.
Forged Steel Gate Valve The pressure problem is often ignored. During the grease injection operation, the grease injection pressure has a regular peak-to-valley change. If the pressure is too low, the seal leaks or the safety valve fails. If the pressure is too high, the grease injection port is blocked, the grease in the seal hardens, or the seal ring is locked with the valve ball and valve plate. Usually, when the grease injection pressure is too low, the injected grease flows into the bottom of the valve cavity, which usually occurs in small gate valves. If the pressure of the grease injection flow control valve is too high, on the one hand, check the grease injection nozzle of the thermal insulation gate valve. If the grease is blocked, replace it; on the other hand, the plunger stop valve is hardened by grease. Use cleaning fluid to repeatedly soften the failed sealing grease and inject new grease to replace it. In addition, the seal model and seal material also affect the grease injection pressure. Different seal forms have different grease injection pressures. Generally, the grease injection pressure of hard seals is higher than that of soft seals.
Pay attention to the problem of the switch position of the forged steel stop valve. The ball valve is generally in the open position during maintenance, and closed maintenance is selected in special circumstances. Other valves cannot be treated as open positions. The forged steel stop valve must be in the closed state during maintenance to ensure that the grease fills the sealing groove along the sealing ring. If it is open, the sealing grease will directly fall into the flow channel or valve cavity, causing waste. When greasing the valve, the grease injection effect is often ignored. The pressure, grease injection amount, and switch position are normal during the grease injection operation. However, in order to ensure the effect of valve grease injection, it is sometimes necessary to open or close the valve, check the lubrication effect, and confirm that the surface of the valve ball or gate is evenly lubricated.
Forged steel check valves should pay attention to the problem of valve body drainage and screw plug pressure relief. After the valve pressure test, the gas and moisture in the sealing chamber valve cavity increase due to the increase in ambient temperature. When injecting grease, it is necessary to first drain and release the pressure to facilitate the smooth progress of the grease injection. After grease injection, the air and moisture in the sealing cavity are fully replaced. Timely release of valve cavity pressure also ensures the safety of valve use. After grease injection, be sure to tighten the drainage and pressure relief screw plugs to prevent accidents. When injecting grease, pay attention to the problem of uniform grease output. During normal grease injection, the grease output hole closest to the grease injection port will first output grease, then to the low point, and finally to the high point, and then output grease one by one. If it is not regular or no grease is output, it proves that there is a blockage and it should be cleared in time.
For forged steel extended end gate valves, observe the problem of valve diameter and sealing ring seat being flush. For example, if there is an interference in the opening position of a ball valve, the opening limiter can be adjusted inward, and locked after confirming that the diameter is straight. When adjusting the limit, you cannot only pursue the opening or closing position, but also consider the overall situation. If the opening position is flush and the closing position is not in place, the valve will not be closed tightly. Similarly, when adjusting the closing position, you should also consider the corresponding adjustment of the opening position. Ensure the right-angle stroke of the valve. After grease injection, be sure to seal the grease injection port. Avoid impurities from entering or lipid oxidation at the grease injection port. Apply anti-rust grease to the cover to avoid rust. So that it can be used for the next operation.
The sealing surface of the high-pressure forged steel gate valve is flat or conical, and the opening and closing part is a plug-shaped valve disc, which moves linearly along the center line of the fluid. The movement form of the valve stem is a lifting rod type (the valve stem is lifted and lowered, and the handwheel does not lift and lower), and there is also a lifting and rotating rod type (the handwheel rotates and lifts with the valve stem, and the nut is set on the valve body). The corrugated tube stop valve is only suitable for full opening and full closing, and adjustment and throttling are not allowed.
Forged steel low-temperature valves should consider specific problems in the future oil product sequential transportation. In view of the different qualities of diesel and gasoline, the flushing and decomposition ability of gasoline should be considered. In the future valve operation, when encountering gasoline section operation, add grease in time to prevent wear. When injecting grease, do not ignore the injection of grease on the valve stem. There are sliding sleeves or packings on the valve shaft, which also need to be lubricated to reduce the friction resistance during operation. If lubrication cannot be ensured, the torque will increase during electric operation and the wear parts will be worn, and the switch will be laborious during manual operation.
Some ball valves are marked with arrows on the valve body. If there is no English FIOW handwriting, it is the direction of the sealing seat, not as a reference for the medium flow direction, and the valve self-drain direction is opposite. Usually, the ball valve with double seat seal has a two-way flow direction.