How to Select the Plug Valve?

The plug valve is a quick-opening and closing two-way valve. Cause the movement between the plug and sealing surfaces has a wiping effect, it can completely prevent touching with the flowing medium when fully open, so it can usually be used for media with suspended particles.

The shape of the plug can be cylindrical or conical. Cylindrical plugs, the channels are generally rectangular; Conical plugs, the channels are trapezoidal. These shapes make the plug valve lightweight in construction. The plug valve is suitable for cutting off, connecting the medium, and diverting the flow. However, depending on the applicable properties and the erosion resistance of the sealing surface, it can sometimes be used for throttling.

As a traditional valve for fluid control, plug valves have high requirements for sealing performance. They are widely used in petroleum, chemical industry, metallurgy, electric power, environmental protection, and other aspects. So, how to choose the plug valve correctly?

If the plug valve is used to distribute media and change the flow direction of the medium, the operating temperature is ≤300℃, the nominal pressure is ≤1.6MPa, and the nominal diameter is ≤300mm, it is recommended to use a multi-channel plug valve. Due to its multi-channel structure, one valve can have two, three, or even four different flow channels. This simplifies the design of the piping system and reduces the number of valves and connecting accessories required in the equipment.

If the fluid medium is on equipment and pipelines in milk, juice, beer, and other food companies and pharmaceutical factories, it is recommended to use CF3/CF8 stainless steel tight-fitting conical plug valves. The food and medical industries have high corrosion resistance and hygienic requirements for valves. CF3M/CF8M stainless steel materials are wear-resistant, corrosion-resistant, and have high cleanliness.

In branch pipes, refining and cleaning equipment for oil mining, natural gas field mining, and pipeline transportation, if the nominal pressure level is ≤ CL300, the nominal diameter is ≤ 300 mm and the operating temperature is ≤ 340°C, it is recommended to use oil-sealed conical plug valves. Oil-sealed conical plug valve: It adopts forced lubrication to form an oil film between the plug and the valve body sealing surface, and has good sealing performance. It should be noted that the sealing oil in the valve body may contaminate the medium in the pipeline, so attention must be taken when selecting it.

In branch pipes, refining and cleaning equipment for oil field mining, natural gas field mining, and pipeline transportation, if the nominal pressure level is ≤ CL2500, the nominal diameter is ≤ 900 mm and the operating temperature is ≤ 340°C, it is recommended to use a pressure-balanced inverted cone plug valve. The valve can meet high-pressure working conditions without getting stuck.

In large chemical industries, where pipelines and equipment containing corrosive media require faster opening or closing speeds, for nitric acid-based media, CF8/CF3 stainless steel PTFE sleeve seal conical seals can be used as Plug valve; for acetic acid-based media, a PTFE sleeve-sealed conical plug valve made of CF8M/CF3M stainless steel can be used.

In pipelines and equipment of gas, natural gas, and HVAC systems, when the nominal pressure is ≤1.0MPa and the nominal diameter is ≤200mm, it is advisable to use a packed conical plug valve. This type of valve has a simple structure, is easy to maintain, has small pressure and diameter, and is widely used.

Compared with conventional gate valves and ball valves, plug valves have complex structures, high costs, and few applications. Because of its reliable sealing performance and long service life, it has more advantages when used in special working conditions. Users can choose various valve body materials and structures, plug materials, soft sealing bushing materials, etc. according to the client’s requirement.