Plug Valves Manufacturers

Plug valves is a rotary valve in the form of a closing member or a plunger, which can be opened or closed by rotating 90 degrees to connect or separate the channel port on the valve plug and the channel port on the valve body.

Its valve plug may be cylindrical or conical in shape. In a cylindrical valve plug, the passage is generally rectangular; While in the conical valve plug, the channel is trapezoidal. These shapes make the structure of the plug valve lightweight. It is most suitable for cutting off and connecting medium and shunting, but sometimes it can also be used for throttling according to applicable properties and erosion resistance of sealing surface.

The plug valve is a quick opening and closing through valve. Since the movement between the rotary sealing surfaces has a wiping effect, and the contact with the flowing medium can be completely prevented when it is fully opened, it can also be used for the medium with suspended particles. Another important feature is that it is easy to adapt to the multi-channel structure, so that one valve can obtain two, three, or even four different flow channels. This can simplify the design of the pipeline system, reduce the consumption of valves and some connecting fittings required in the equipment.

working principle

A valve with a plug body with a through hole as a hoist. The plug body rotates with the [2] valve rod to realize the opening and closing action. The small plug valve without packing is also called “cock”. The plug body of the plug valve is mostly a cone (or a cylinder), which cooperates with the conical hole surface of the valve body to form a sealing pair. Plug valve is one of the earliest valves used, with simple structure, quick opening and closing, and small fluid resistance. Ordinary plug valves are sealed by the direct contact between the finished metal plug body and the valve body, so the sealing property is poor, the opening and closing force is large, and it is easy to wear. Generally, they can only be used in low pressure (not higher than 1 MPa) and small diameter (less than 100 mm).

According to the structural form, it can be divided into four types: fixed plug valve, self sealing plug valve, plug valve and oil filling plug valve. According to the channel form, it can be divided into three types: straight plug valve, three-way plug valve and four-way plug valve. There are also ferrule type plug valves.

The plug valves are classified into soft seal plug valves, oil lubricated hard seal plug valves, poppet plug valves, three-way and four-way plug valves according to their applications.

Soft seal

Soft seal plug valves are often used in harsh environments such as corrosive, highly toxic and highly hazardous media, where leakage is strictly prohibited, and where the valve materials will not pollute the media. The valve body can be made of carbon steel, alloy steel and stainless steel according to the working medium.

Oil lubricated hard seal

Oil lubricated hard seal plug valves can be divided into conventional oil lubricated plug valves and pressure balanced plug valves. Special lubricating grease is injected from the top of the plug body between the tapered hole of the valve body and the plug body to form an oil film to reduce the opening and closing torque of the valve and improve the sealing performance and service life. The working pressure can reach 64mpa, the maximum working temperature can reach 325 degrees, and the maximum diameter can reach 600mm.

Lifting type

There are many structural forms of poppet cocks. The poppet cocks are divided into soft seal and hard seal according to the material of the sealing surface. The basic principle is to make the cock rise when it is opened, and then turn the cock 90 degrees to fully open the valve to reduce the friction with the sealing surface of the valve body; When closing the valve, turn the cock 90 degrees to the closed position and then lower it to contact with the sealing surface of the valve body to achieve sealing.

Tee and cross type

The three-way and four-way plug valves are suitable for changing the medium flow direction or distributing the medium in the device. According to the requirements of service conditions, soft seal bushing or soft seal, hard seal poppet plug valve can be selected

advantage

1. The plug valve is used for frequent operation, with quick and light opening and closing.

2. The plug valve has small fluid resistance.

3. The plug valve is simple in structure, small in relative volume, light in weight and convenient for maintenance.

4. Good sealing performance.

5. It is not limited by the installation direction, and the flow direction of the medium can be arbitrary.

6. No vibration and low noise.

passageway

There are many forms. The common through type is mainly used to cut off the fluid. The three-way plug valve and the four-way plug valve are applicable to the fluid reversing plug valve. The opening and closing part is a cylinder with holes, which rotates around the axis perpendicular to the channel, so as to achieve the purpose of opening and closing the channel.