Matters Needing Attention And Classification When Operating Forged Steel Valves
Forged Steel Valve The problem of grease injection amount is often ignored. After the grease gun is refueled, the operator selects the valve and grease injection connection method, and then performs grease injection. There are two situations for forged steel 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 valves often ignore the pressure problem. During the grease injection operation, the grease injection pressure has a regular peak-to-valley change. If the pressure is too low, the seal will leak or the safety valve will fail. If the pressure is too high, the grease injection port will be blocked, the grease in the seal will harden, or the seal ring will be locked with the valve ball and valve plate. Usually, when the grease injection pressure is too low, the injected grease will flow 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. 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.
Forged steel stop valves should pay attention to the problem of valve switching position. Ball valves are generally in the open position during maintenance, and closed maintenance is selected under special circumstances. Other valves cannot be treated as open positions. Forged steel stop valves 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 all 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 perform drainage and pressure relief to facilitate the smooth progress of 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 output grease first, then to the low point, and finally to the high point, and grease will be output one by one. If it is not regular or no grease is output, it proves that there is blockage and it should be cleared in time.
For the extended end forged steel gate valve, observe the problem of the valve diameter and the seal 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 cap to avoid rust. So that it can be applied during the next operation.
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 capabilities of gasoline should be considered. In the future valve operation, when encountering gasoline section operations, add grease in time to prevent wear. When greasing, do not ignore the greasing of the valve stem. There are sliding sleeves or packings on the valve shaft, which also need to be lubricated to reduce friction resistance during operation. If lubrication cannot be ensured, the torque will increase during electric operation and wear parts, and it will be difficult to switch during manual operation.
Some ball valves are marked with arrows on the valve body. If there is no English FIOW, it is the direction of the sealing seat, not as a reference for the flow direction of the medium, and the valve self-drain direction is opposite. Usually, the double-seat sealed ball valve has a bidirectional flow.
Forged steel valves can be specifically classified into forged steel check valves, forged steel gate valves, forged steel ball valves, forged steel stop valves, forged steel check valves, self-sealing gate valves, self-sealing stop valves, self-sealing check valves, forged steel needle valves, forged steel insulation valves, forged steel bellows valves, etc.
