Gate Valve

A gate valve is a fundamental component in fluid-handling systems.

Structure and Components

The gate valve consists of a valve body, a gate or wedge, a stem, a bonnet, and seat rings. The valve body is the main housing that provides a passage for the fluid. The gate, usually in a flat or wedge-shaped form, is the element that controls the flow. The stem connects the gate to the actuator on the outside of the valve and is used to raise or lower the gate. The bonnet seals the internal parts of the valve from the external environment and provides a housing for the stem. Seat rings are located at the inlet and outlet of the valve body and provide a sealing surface for the gate.

Working Principle

When the gate valve is fully open, the gate is completely lifted out of the flow path, allowing the fluid to pass through with minimal resistance. This provides a full-bore flow, which means the fluid can flow through the valve with almost the same velocity and pressure drop as if there were no valve present. To close the valve, the gate is lowered into the flow path until it seats against the seat rings, blocking the fluid completely.

Advantages

Gate valves are well-known for their excellent shut-off capabilities. They can provide a tight seal, preventing any leakage of the fluid when closed. They are also suitable for a wide range of fluid types, including liquids, gases, and slurries. Their full-bore design allows for high-volume flow rates, making them ideal for applications where a large amount of fluid needs to be transferred quickly.

Disadvantages

One of the main drawbacks of gate valves is that they operate relatively slowly compared to other valve types like ball valves or butterfly valves. The process of fully opening or closing the valve can take more time because of the way the gate moves in and out of the flow path. Additionally, gate valves are not well-suited for throttling applications. When the gate is partially open, the flow pattern becomes turbulent and can cause erosion of the gate and seat, leading to a decrease in sealing performance over time.

Applications

Gate valves are widely used in industries such as water supply and sewage treatment, oil and gas, power generation, and chemical processing. In water supply systems, they are used to control the flow of water in large-diameter pipes. In the oil and gas industry, they are used to isolate different sections of pipelines and storage tanks. In power plants, they are used to regulate the flow of steam and cooling water.

1) Fusion-bonded epoxy 200-250 microns inside and out side.

2) Coating as per customers' requirement.

Product Information: the gate valves supplied are mainly used for adjusting water, steam, oil, gas, and natural gas in chemical industries.

Standards: AWWA, DIN3352 F4/F5, BS5163, BS5150.

Connection Type: flanged type, push-on type, mechanical joint type, plain ends type.

Pipe Wall Thickness: K7/K8/K8/K12/C40, /C30/C25.

Joint Type: Tyton / push-on joint, K type / mechanical joint, self-anchored / restrained joint.

Gasket: SBR, EPDM, NBR.