Gate valve

Gate valves are among the most common types of industrial valves today. They are widely used in water supply and drainage systems, as well as in oil and gas, steam, and many other applications. With a simple yet efficient design, gate valves enable quick and secure opening and closing of the flow, ensuring both safety and optimal operational performance.

In the content below, join Bao Tin Steel to learn more about what gate valves are, their structure, and how they work. Additionally, discover many other useful insights—check it out now!

What is a Gate Valve? Structural Features

Definition of Gate Valve

A gate valve (also known as a shut-off valve or sluice valve) is an industrial valve designed primarily to open or close the flow in a pipeline fully. It is widely used in water supply and drainage systems, water treatment, fire protection (FHC), oil and gas, and various other industries due to its efficient operation under high-pressure and large flow conditions.

When fully open, the valve disc does not obstruct the flow, minimizing pressure loss in the system.

Structural Features

A standard gate valve typically consists of six main components:

Valve Body: Made from cast iron, steel, stainless steel, brass, etc., often coated with epoxy paint to prevent corrosion.
Valve Disc: Directly controls the flow, usually made of ductile iron or stainless steel, often lined with EPDM rubber to enhance sealing.
Valve Stem: A metal shaft connecting the handwheel to the disc, designed to withstand high stress and friction.
Bonnet: Allows disassembly and maintenance of the valve disc.
Handwheel: Controls the opening and closing of the valve.
Sealing Gasket: Prevents leakage and ensures stable pressure.

Operating Principle of a Gate Valve

The operating principle of a gate valve is very simple, based on the vertical movement of the valve disc (or gate) to control the flow.

Closing the Valve (Disc Lowered): When the handwheel is turned clockwise, the valve stem moves downward along with the disc, pressing tightly against the sealing gasket inside the valve body. At this point, the flow is completely blocked.

Opening the Valve (Disc Raised): When the handwheel is turned counterclockwise, the valve stem moves upward, lifting the disc along with it. At this point, the valve is fully open, allowing the fluid to pass through freely without obstruction.

Prominent Gate Valve Types at Bao Tin Steel

Gate valves come in various types. Based on their structure and materials, they can be classified as follows:

Phân theo đặc điểm cấu tạo

Classification by Structural Features

Rising Stem Gate Valve

This type has a stem that rises and lowers during operation. When the valve is open, the stem protrudes, making it easy to visually identify whether the valve is open or closed. However, it requires more installation space above the valve.

Non-Rising Stem Gate Valve

In contrast, the stem does not move up or down but only rotates in place, remaining entirely within the valve body. This design is compact and saves installation space.

Classification by Material

Cast Iron Gate Valve
Typically made from grey cast iron or ductile iron. Widely used in water supply and drainage systems, wastewater treatment, and fire protection. Its reasonable cost makes it very popular.

Brass Gate Valve
Compact in size, commonly used in residential systems or light industrial applications. The brass material provides durability and excellent corrosion resistance.

Stainless Steel Gate Valve
Made from stainless steel (grades 201, 304, 316). Durable, heat-resistant, and corrosion-resistant, but generally more expensive than other types.

Classification by Connection Type

Flanged Valve
A common connection type for large valves. Both ends of the valve have flanges that are bolted to the pipeline.

Threaded Valve
Typically used for small-sized valves (below DN50). Both ends have internal or external threads to screw directly into the pipeline.

Welded Valve
Provides a completely leak-proof connection, used in high-pressure and high-temperature systems. The valve is welded directly to the pipeline to form a seamless unit.

Classification by Operation Method

Handwheel Gate Valve
Operated with a handwheel. The operator turns clockwise to close the valve and counterclockwise to open it.

Electric/Pneumatic Actuated Gate Valve
Used in automated systems. Electric actuated valves use an electric motor, while pneumatic actuated valves use air pressure to operate remotely.

Practical Applications of Gate Valves

Water Supply & Wastewater Treatment: Widely used in main pipelines, pumping stations, and water treatment plants due to their reasonable cost and high durability.
Oil & Gas: Steel or stainless steel valves can withstand high pressure and temperature, ensuring safety for oil and natural gas pipelines.
Power Plants: Used to control water and steam in boilers, thermal turbine systems, and hydroelectric plants.
Chemical & Food Industry: Stainless steel valves offer corrosion resistance and maintain high hygiene standards, suitable for pharmaceutical and food production.
Mining, Cement, & Pulp & Paper: Knife gate valves handle thick fluids containing solids such as sludge or powder, preventing pipeline clogging.

Gate Valve Installation Guide

To ensure the gate valve operates efficiently and without leakage, it must be installed correctly. The basic steps include:

Gate Valve Installation and Operation Guide

Preparation Before Installation

Inspect the valve condition (surface, gasket, stem) before installation.
Ensure the pipeline is clean, free of debris, rust, or foreign objects.
Select the correct type, size, and pressure rating of the valve.

Determining Installation Position

Gate valves are usually installed at main flow shut-off points.
Provide sufficient space for operating the valve and performing maintenance.

Installing the Gate Valve

Flanged Valves: Align the two flanges concentrically, place the gasket, and tighten bolts in a cross pattern to ensure even force distribution.
Threaded Valves: Wrap Teflon tape on the pipe threads and tighten just enough to prevent leaks without cracking the threads.

Post-Installation Check

Operate the valve (open and close) to ensure smooth movement.
Check for leaks at connection points.
If leakage occurs, retighten bolts or replace the gasket.

Operation Notes

Gate valves should be used for full open/close only; they are not suitable for flow regulation.
Avoid excessive force when closing to prevent damage to the disc and gasket.
Regularly inspect and perform maintenance to ensure the valve’s long service life.

Current gate valve brands and quotes

Here are the famous gate valve brands on the market:

MIHA brass gate valve

Product by Minh Hòa, made of brass. Size DN15 – DN100, maximum pressure 16 bar, suitable for small‑diameter pipelines.

Price from 113,000 VND to over 4,000,000 VND/piece depending on size.

Wonil Threaded Stainless Steel Gate Valve

Manufactured in South Korea, featuring glossy 304 stainless steel material. Sizes range from DN15 to DN50.

Reference Price: 340,000 VND – 1,250,000 VND per unit.

ShinYi Rising Stem Gate Valve with Handwheel

Originating from Taiwan, used for water supply and drainage systems (blue valve) and fire protection systems (PCCC – red valve). Sizes range from DN50 to DN300.

Reference Price: 2,522,000 VND – 21,430,000 VND per unit.

Comparison Between Gate Valve and Butterfly Valve

Below are the fundamental differences between the Gate Valve and the Butterfly Valve:

Criterion	Gate Valve	Butterfly Valve
Operating Principle	The disc slides up/down to open/close the flow.	The disc rotates around its axis ( $0–90^\circ$ ) to open/close the flow.
Size & Weight	Large, heavy body; occupies significant space.	Compact, lightweight; saves space.
Opening/Closing Speed	Slow; requires multiple turns of the handwheel.	Fast; requires only a quarter turn ( $90^\circ$ ).
Flow Control Capability	Unsuitable; disc easily wears out with frequent throttling.	Suitable; easy to adjust flow rate.
Sealing & Pressure	Excellent sealing; withstands high pressure.	Moderate sealing; medium pressure rating.
Cost	Higher initial cost; more complex maintenance.	Lower initial cost; easier maintenance.
Application	Oil & gas, power plants, high-pressure water supply.	Water supply & drainage, wastewater treatment, F&B, HVAC, Fire Protection (PCCC).

Conclusion

Gate valves are diverse in terms of materials, sizes, and standards. Please thoroughly research their characteristics to select the appropriate type.

Currently, many brands supply gate valves, providing more options for construction projects. However, to purchase genuine products at a good price, choose a reputable supplier.

Bao Tin Steel is committed to providing $100\%$ new, genuine products with complete quality inspection documents. Contact us immediately for the fastest and most accurate quotation!