What is non-lubricated plug valve?
Non-lubricating valves are used to regulate the process fluid, such as sulfur, hydrogen fluoride, or where liquids could be trapped or solidified and potentially clog the valve.
What is an eccentric plug valve?
What is an eccentric plug valve? A style of rotary control valve with a plug-shaped, flow-restricting member that follows an eccentric path as it rotates. The plug has no contact with its seat until it turns within a few degrees of the shutoff position.
What is the purpose of a plug valve?
Usually available in cylindrical or conical shapes, plug valves are quarter-turn manual motion valves used for stopping or starting the flow of fluid. They offer on-off, diverting, as well as basic moderate throttling services.
Why plug valves are used?
Besides being compact and using up less space, plug valves offer the following advantages: Flow Regulation – Tight shut-off, quick opening and low-pressure drop. Fire-safety and Durability – Reduced likelihood of corrosion or erosion as the actual plug and body seating surface do not get exposed to the line fluid.
How does a gas plug valve work?
A plug valve is based on a plug with a hollow passage in the valve body. The quarter-turn motion creates an alignment between the pipe and the hole, leading to an open state. When turned to a 90-degree angle from the open position, the valve sits across the pipe leading to a closed state.
What is a plug valve for natural gas?
Plug Valves Featuring a conical tapered or a cylindrical disc, a plug valve controls fluid movement through one or more passages that go sideways through the plug. When the valve is open, the hollow passage aligns with the flow, allowing the fluid to flow freely.
What is a plug valve made of?
Plug material – the material from which the flow control plug is constructed. Common material options include brass, stainless steel, or plastic. Valve shape – represents the valve shape as being inline, L, or T.
Can a plug valve be used for throttling?
A plug valve is a quarter-turn manual valve that uses a cylindrical or tapered plug to permit or prevent straight through flow through the body. The plug has a straight through full port opening. Plug valve can be used in on-off, basic moderate throttling, and diverting services.
What type of valve is best for throttling?
Among the most common valves, the butterfly valve is the most suitable for throttling. A full quarter turn can open or close the valve. For throttling to happen, it only needs to open a bit for the media to pass.
When would you use a plug valve?
Plug valves are commonly used in low-pressure-low-temperature services, although some high-pressure-high-temperature designs also exists. Plug valves are high capacity valves that can be used for directional flow control, even in moderate vacuum systems. Plug valves can efficiently handle gas and liquid fuel.
What is a non-lubricated plug valve?
Non-lubricated plug valves have a sleeve or liner installed in the cavity. The tapered plug wedges the sleeve against the plug body. In this way, the non-metallic sleeve decreases friction during operation.
How to use a lubricated plug valve properly?
When using a lubricated plug valve, it is essential to match the sealant with the medium flowing through it. Otherwise, you could contaminate the fluid. The sealant also must be able to withstand high temperatures if required by the application. Plastic sealants are used to lubricate plug valves.
What are the different types of plug valves?
There are two types of plug valves: lubricated and non-lubricated. This guide explains the difference between these two main types of plug valves. Learn the advantages, disadvantages, and applications of each so that you can answer your customers’ questions about this simple but highly effective equipment.
What is a plug valve and how does it work?
Plug valves are on-off valves used in a wide variety of applications. Users choose them for frequent operation tasks, and they are quarter-turn valves. There are three port patterns: regular, Venturi, and short. You can learn more about plug valves by reading our previous article: What is a Plug Valve and What is it Used for.