Precautions for Forged Steel Valves

Precautions for Forged Steel Valves

Mar 21, 2024

Forged steel valves are mainly used in various systems' pipelines of thermal power stations. They can be used to control the flow of various types of fluids such as air, water, steam, corrosive media, mud, oil, liquid metal, and radioactive substances. Compared to other valve products, forged steel valves are characterized by their high temperature and high-pressure resistance, unique self-sealing design, and increased reliability with higher pressures. Due to their performance characteristics and special operating conditions, these products have become irreplaceable.

Forged steel valves can be classified into several types, including forged steel check valves, forged steel gate valves, forged steel ball valves, forged steel globe valves, self-sealing gate valves, self-sealing globe valves, self-sealing check valves, forged steel needle valves, forged steel insulation valves, high-pressure forged steel gate valves, and forged steel bellows valves.

Forged Steel Valves Drawing

Forged steel valves often overlook the issue of grease injection. After greasing with a grease gun, the operator selects the valve and grease joint for grease injection operations. However, there are two situations with forged steel gate valves: insufficient grease injection leads to accelerated wear of the sealing surface due to a lack of lubricant, while excessive grease injection leads to waste. This occurs because precise calculations are not made based on the valve type category for different sealing capacities. Calculating the sealing capacity based on valve size and category can determine the appropriate amount of grease to inject.

Forged steel gate valves often neglect pressure issues. During greasing operations, the grease injection pressure exhibits peak-valley changes. If the pressure is too low, sealing leakage or safety valve failure may occur, while excessively high pressure can cause grease nozzle blockages, hardening of internal grease, or seizing between the sealing ring and valve ball or valve plate. Adjusting the grease injection pressure is crucial, considering factors such as seal type and material, as different sealing forms have different grease injection pressures.

Forged steel globe valves must pay attention to the valve position during maintenance. While ball valves are generally maintained in the open position, special cases may require closure for maintenance. Other valves should not be treated solely based on the open position. Forged steel globe valves must be closed during maintenance to ensure that grease fills the sealing groove along the sealing ring. Failure to close the valve during maintenance can result in grease directly falling into the passage or valve cavity, causing waste.

When greasing forged steel check valves, attention should be paid to valve body drainage and thread blockage for pressure relief. After pressure testing the valve, the pressure in the sealing cavity increases due to the rise in environmental temperature, necessitating drainage and pressure relief before greasing to facilitate smooth grease injection operations. Proper drainage ensures the displacement of air and moisture from the sealing cavity. After greasing, it is essential to tighten the drain and pressure relief plugs to prevent accidents.

Forged steel extended stem gate valves need to observe whether the valve diameter is aligned with the sealing ring seat. For example, if a ball valve exhibits excessive clearance in the open position, the open position limiter can be adjusted inward, ensuring alignment of the diameter after locking. Adjusting the limiter should not solely focus on one position (open or closed), but consider the overall situation. Failure to align the open position can result in incomplete valve closure. Similarly, adjusting the closed position should consider corresponding adjustments to the open position to ensure a perpendicular stroke of the valve. After greasing, the grease injection port must be sealed to prevent impurities from entering or grease oxidation at the injection port, applying anti-rust grease for future operations.

Steel and iron are both iron-based alloys with carbon as the primary additive element, collectively referred to as ferroalloys. Casting pig iron in a cupola furnace yields molten iron, which, when cast, produces cast iron (in liquid form), resulting in cast iron components. The distinction between cast steel and carbon steel lies in their chemical composition. Carbon steel is classified by its chemical composition: low carbon steel (C≤0.25%), medium carbon steel (C≤0.25~0.60%), and high carbon steel (C≥0.60%). Steel can also be classified by forming method: forged steel, cast steel, hot-rolled steel, and cold-drawn steel.


Next: What are Forged Steel Gate Valves and Their Industrial Applications?

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Launched in 1988, Topper Forged Valve Company is engaged in manufacturing forged steel valves. Our products cover Forged Steel Ball Valve, Gate Valve, Check Valve, Globe Valve, According to API, BS, DIN, JIS GB Standards.
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