Principles for selecting Plug Valves
According to the structural characteristics of the plug valve and the functions that can be achieved in the design, it can be selected according to the following principles.
① For distributing media and changing the flow direction of the media, its working temperature is not higher than 300℃, the nominal pressure PN≤1.6MPa, and the nominal diameter is not greater than 300mm. It is recommended to use a multi-channel plug valve.
② In the pipelines and equipment of coal gas, natural gas, and HVAC systems, the nominal diameter is not greater than 200nm, and it is advisable to use a stuffing-type conical plug valve.
③ In the branch pipes, refining and cleaning equipment of oil field exploitation, natural gas field exploitation, and pipeline transportation, the nominal pressure level is not greater than Class300 and the nominal diameter is not greater than 300mm. It is recommended to use an oil-sealed conical plug valve.
④ For equipment and pipelines of food enterprises such as milk, juice, beer, and pharmaceutical factories, it is recommended to use austenitic stainless steel, tight-fitting conical plug valves.
⑤ In large-scale chemical industries, in pipelines and equipment containing corrosive media, where a faster opening or closing speed is required, a polytetrafluoroethylene sleeve sealed conical plug valve can be selected for nitric acid-based media; for acetic acid-based media, a Crl8Nil 2M02Ti stainless steel polytetrafluoroethylene sleeve sealed conical plug valve can be selected.
⑥ In branch pipes, refining and cleaning equipment for oilfield exploitation, natural gas exploitation, pipeline transportation, the nominal pressure level is not greater than Class7500, the nominal diameter is not greater than 900mm, and the working temperature is not higher than 340℃, it is recommended to use an oil-sealed conical plug valve.

Installation and maintenance of plug valves
When installing plug valves, in order to prevent damage to the plug valves and ensure full utilization of the working performance of the plug valves, the following four points should be noted:

1. Make sure the valve is in the open state. Heat the pipeline first. Transfer as much heat as possible from the pipeline to the plug valve. Avoid extending the heating time of the plug valve itself.

2. Use gauze or wire brush to clean the pipe and cut parts to make the metal surface shiny. It is recommended not to use steel wool.

3. Cut the pipe in the vertical direction first, trim and remove burrs, and measure the pipe diameter.

4. Apply flux to the outside of the pipe and the inside of the welding cover. The flux must completely cover the welding surface. Please use flux sparingly.