Forged steel gate valves are a vital valve assembly, primarily used for full open and full close operations, with the closing element (gate) moving vertically along the centerline of the passage. The operating parts of the forged steel gate valve are the gate, whose movement direction is perpendicular to the fluid direction, indicating that it can only perform full open and full close operations, not adjustment or throttling.

Definition and Working Principle

A forged steel gate valve is a valve where the closure element (gate) moves vertically along the centerline of the passage. When the valve is in the closed position, the gate forms a sealed space with the valve seat, blocking the flow of the medium; when the valve is open, the space between the gate and the seat is opened, allowing the medium to flow freely. The opening and closing of the valve is achieved by rotating the valve stem, which moves the gate up and down to control the flow of the medium.

Structure and Classification

Forged steel gate valves are mainly composed of the valve body, gate plate, valve stem, valve cover, and sealing surface. They can be categorized by the sealing surface as wedge gate valves and parallel gate valves, by the actuation method as manual, pneumatic, electric, and pneumatic-hydraulic actuated, by the connection method as flanged, welded, and threaded, and by pressure class as high pressure and low (medium) pressure gate valves.

Features and Performance

Forged steel gate valves feature the following characteristics:

Low fluid resistance: At full open, the sealing surface is subject to less erosion by the working medium compared to a throttling valve.

The required external force for opening and closing is minimal: the flow direction of the medium is unrestricted.

High Pressure Resistance: Capable of withstanding the working requirements under high-pressure environments, ensuring stable operation under high temperature and pressure conditions.

Corrosion Resistance: Forged steel material boasts excellent corrosion resistance, suitable for a variety of mediums, including liquids and gases with strong corrosive properties.

However, forged steel gate valves do have some drawbacks:

‌Large dimensions: requires more installation space.

Sealing Surface Friction: Relative friction between sealing surfaces during the opening and closing process can easily cause abrasion, requiring high operating torque. Additionally, it is prone to scratching on the gate and valve seat sealing surfaces, leading to valve leakage.