The stem and handle often come in one piece, often a simple, approximately L-shaped handle attached to the end of the plug. Standards such as API STD 599 covers design, materials, face-to-face dimensions, pressure-temperature ratings, and test requirements for metallic plug valves. Today, they remain one of the most widely used valves for both on/off and throttling services. The plugs in plug valves have one or more hollow passageways going sideways through the plug, so that fluid can flow through the plug when the valve is open.
Pinch valves include any valve with a flexible elastomer body that can be pinched closed, cutting off flow, using a mechanism or fluid pressure. IEEE GlobalSpec may share your personal information and website activity with our clients for which you express explicit interest, or with vendors looking to reach people like you. Non-lubricating plug valves required minimum maintenance. Here you can see the 3-way multiport plug valve.
https://engineering.fandom.com/wiki/Plug_valve?oldid=7858. In this case the plug can be rotated 180° to connect the port on the one side to either of the two ports on the other side.
They are high capacity valves that can be used for directional flow control, even in moderate vacuum systems. An error occurred while processing the form. Solenoid valves are devices that use a solenoid to control valve activation. The disk is in plug shape, which has a passage to pass the flow. In the open position, this bored passage is in line with the flow. For a non-lubricated type, a non-metallic seat is used to improve leak tightness of the valve. This makes this kind of plug valve a quarter-turn valve.
Also, the sealant used must be able to withstand the temperature of the flow medium. Plug valves have one or more hollow passageways often placed horizontally to allow ease of flow through the valve when open. When the plug is conically-tapered, the stem/handle is typically attached to the larger diameter end of the plug. Ports are openings in the valve body through which fluid can enter or leave. 1. It is used in place of a gate valve where the quick operation is required. The simplest and most common general type of plug valve is a 2-port valve, which has two positions, open to allow flow, and shut (closed) to stop flow. Use of this website signifies your agreement to our Terms of Use. Plug surface gets constantly lubricated by the sealant that moves from the center cavity through radial holes into lubricant grooves on the plug surface. Also used in a vacuum to high-pressure & temperature applications, Multiple port design helps reduce the number of valves needed and permits a change in a flow direction, It requires greater force to operate, due to high friction, Larger valves cannot be operated manually and required an actuator, Cost of Plug valves may be more than ball valves for given size and class. They may have various types of port openings, each with a varying degree of the opening area.
They are widely used in industry to regulate fluid flow in both on/off and throttling service. It should not dissolve or wash away by the flow medium as this could contaminate the fluid, and damage the seal between the plug and the body, resulting in leakage. Globe valves are linear motion valves with rounded bodies, from which their name is derived.
Otherwise, they can be made of an inert plastic such as Teflon. The plug in this kind of valve has one passageway going through it. It can be used in different types of fluid services such as Air, gaseous, vapor, Hydrocarbon, slurries, mud, and sewage applications. The lubricant reduces the force required to open or close the valve and allows smooth movement of the plug. For more information on valves, including different types of actuation and flow coefficient, please see Industrial Valves Information.
The connection used depends on the pressure and temperature of the working fluid as well as the frequency of the pipeline will be dismantled (valve removed from the line).
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When fused with the glassware, the valve bodies are made of glass. An additional possibility in plug valves is to have one port on one side of the plug valve and two ports on the other side, with two diagonal and parallel fluid pathways inside the plug. They require minimum space, are simple to operate, exhibit a fast response, and add relatively little internal disturbance to the flow. Plug valves, also called cock or stop-cock valves or quarter-turn valves, date back to ancient times, where they were developed for use in citywide Roman plumbing systems. Plug valve is a Quarter-turn rotary motion Valve that uses a tapered or cylindrical plug to stop or start the flow. When glass is used for both the stopcock body and the plug, the contacting surfaces between them are special ground glass surfaces (see Laboratory glassware) often with stopcock grease in between. Plug valves are simple and often economical. Include me in third-party email campaigns and surveys that are relevant to me. The body and tapered plug represent the essential features in plug valves. When the plug is made of glass, the handle and plug are fused together in one piece out of glass. Plug valves are valves with cylindrical or conically-tapered "plugs" which can be rotated inside the valve body to control flow through the valve. Plug valve design is fairly simple; the body is comprised of three main parts: body, cover, and plug. This design is still used, but problems with galling and sticking limit their usefulness. In cases like that, there is usually not much of a stem. Your Ebook will Open in New Tab.
The plugs can be made of a similar plastic or glass. Lubricant chamber at the bottom and the sealant injection fitting at the top ensure the supply of lubricant. The basic design of plug valves is illustrated in Fig. The ports are typically at the opposite ends of the body and therefore require a quarter turn to open and close the system. When the plug is rotated a quarter turn, flow is terminated.
In a 3-way plug valve, flow from one port could be directed to either the second or third port. You can see this in the image.
The lubricant material must be compatible with the fluid of the pipeline. They are normally used as throttling valves to control flow. Plug valves are extremely versatile valves that are found widely in low-pressure sanitary and industrial applications, especially petroleum pipelines, chemical processing and related fields, and power plants. A single multiport valve may serve the purpose of three or four gate valves or other types of the shutoff valve. Special glass stopcocks are made for vacuum applications, such as in use with vacuum manifolds. Nonlubricated-plug valves may use a tapered plug with a mechanical lifting device that unseats the plug before it is turned to reduce the operating torque required.
There are several specifications to consider when selecting a plug valve. Needle valves are small valves used for flow control in liquid or gas services. Lubricated plug valves are available in the large size range, and they are fit to work in high-pressure temperature services.
Notify me about educational white papers. Now why we required all this? Great care should be taken in specifying the particular port arrangement for proper operation. Slightly conically-tapered metal (often brass) plug valves are often used as simple shut-off valves in household natural gas lines. It can be used in high-pressure temperature services.
Butterfly valves control flow through a circular disc or vane by turning the valve's pivot axis at right angles to the direction of flow in the pipe.
The typical plug valve is consisting of a body, bonnet, stem, and plug. Please try again in a few minutes. FREE In the open position, this bored passage is in line with the flow. BEST IDEAS. It also prevents corrosion of the plug. By submitting your registration, you agree to our Privacy Policy. The polished tapered plug acts as a wedge and presses the sleeve against the body. This sleeve is installed in the body cavity of the valve.
This nonmetallic sleeve reduces the friction between the plug and the valve body. Cross-sectional (cut-away) diagram of a simple two-way plug valve with a conically tapered plug shown in open (left) and shut (right) positions. as well as subscriptions and other promotional notifications.