What is a Plug Valve and What is it Used for?

In all fields that use hydraulic systems for operation, gas plug valves are essential for the smooth and efficient operation of the system. Generally offered in cylindrical or conical shapes, plug valves are quarter-turn manual action valves used to stop or start fluid flow. They provide opening, closing, redirecting and basic intermediate adjustment functions.

How do plug valves work?

Plug valves are based on a plug with a hollow passage in the valve body. A quarter-turn action creates alignment between the pipe and the hole, resulting in an open position. Turning to a 90 degree angle from the open position causes the valve to close across the pipe.

2-way plug valve: This design provides an intermediate closure element (plug and sleeve) to provide a straight two-way service for opening and closing functions.

3-way plug valve: This valve usually has a third port located at a right angle from the inlet. This plug valve is useful for switching flows (directing the flow coming in from the inlet between one or two outlets) or combining (directing the flow coming in from two inlets to one outlet).

What applications are plug valves used for?

Plug valves are an excellent choice for a variety of commercial and light industrial applications, including directional flow control, handling gas or liquid fuels, fluid conditioning with suspended solids such as slurries, and low-pressure, low-temperature service processing. Thanks to their smooth design, in-line maintenance features, leak-proofing, minimal flow resistance, and multi-port design options, gas plug valves are applied in a variety of fields and systems.

What are the types of plug valves?

Lubricated plug valves

Highly suitable for contaminated upstream applications, cast iron lubricated plug valves can handle abrasive or corrosive materials and do not cause clogging. This plug needs to be resealed frequently to maintain optimal effectiveness.

Non-lubricated plug valves

Used in environments with low maintenance costs, non-lubricated plug valves include elastomeric sleeve type, lift type, and fully lined type plug valves.

Expanded plug valves

This valve consists of multiple parts and complex rotary motions to prevent seal wear and friction. It is suitable for preventing product contamination in environments where double shutoff is not required.

Eccentric Plug Valves

Ideal for environments that require high fastening force and minimal friction from open to closed positions, eccentric plug valves are used in a variety of shutoff or flow control systems. This includes sewage, sludge, slurry, air and other services.

Pros and Cons

In addition to being compact and taking up less space, gas plug valves offer the following advantages:

Flow regulation - complete shutoff, fast opening, low pressure drop

Fire safety and durability - the plug and body seat surfaces are not exposed to the piping fluid, reducing the chance of corrosion and erosion.

Versatile - plug valves with higher flow rates are also available.

Some disadvantages of plug valves include:

Not suitable for throttling applications.

High friction, requiring more force to operate.

Friction can occur.

Tapered plug designs have smaller ports by default.

Find the right plug valve for your application

Whether it's gas, liquid, non-abrasive slurry, fuel gas piping systems, chemical industry, splash applications, or applications from vacuum to high pressure, plug valves play a vital role in a wide range of applications and industries.