This article includes a list of references, related reading, or external links, but its sources remain unclear because it lacks inline citations. Please help improve this article by introducing more precise citations.(February 2015) (Learn how and when to remove this message)
Super duplex plug valve.
Plug valves are valves with cylindrical or conically tapered "plugs" which can be rotated inside the valve body to control flow through the valve. 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. Plug valves are simple and often economical.
When the plug is conically tapered, the stem/handle is typically attached to the larger diameter end of the plug. Plug valves usually do not have bonnets but often have the end of the plug with the handle exposed or mostly exposed to the outside. In such cases, there is usually not much of a stem. The stem and handle often come in one piece, often a simple, approximately L-shaped handle attached to the end of the plug. The other end of the plug is often exposed to the outside of the valve too, but with a mechanism that retains the plug in the body.
Handwheel operated plug valve.
The simplest and most common general type of plug valve is a 2-port valve[1][2] with two positions: open to allow flow, and shut (closed) to stop flow. Ports are openings in the valve body through which fluid can enter or leave. The plug in this kind of valve has one passageway going through it. The ports are typically at opposite ends of the body; therefore, the plug is rotated a fourth of a full turn to change from open to shut positions. This makes this kind of plug valve a quarter-turn valve. There is often a mechanism limiting motion of the handle to a quarter turn, but not in glass stopcocks.
Slightly conically tapered metal (often brass) plug valves are often used as simple shut-off valves in household natural gas lines.
It is also possible for a plug valve to have more than two ports. In a 3-way plug valve, flow from one port could be directed to either the second or third port. A 3-way plug valve could also be designed to shift flow between ports 1 and 2, 2 and 3, or 1 and 3, and possibly even connect all three ports together. The flow-directing possibilities in multi-port plug valves are similar to the possibilities in corresponding multi-port ball valves or corresponding multi-port valves with a rotor. 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. 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.
Stopcocks used in laboratory glassware are typically forms of conically tapered plug valves. When fused with the glassware, the valve bodies are made of glass. Otherwise, they can be made of an inert plastic such as Teflon. The plugs can be made of a similar plastic or glass. When the plug is made of glass, the handle and plug are fused together in one piece out of glass. 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. Special glass stopcocks are made for vacuum applications, such as in use with vacuum manifolds. Stopcock grease is always used in high vacuum applications to make the stopcock air-tight. Also if the plug valve is "locked" from being in the open or closed position for an extended amount of time lubricant can be added through the greaser with the valve in service.
^Nehete, Hemant (2020-04-20). Basic Piping Engineering. Walnut Publication. ISBN 978-93-89744-69-9.
Plugvalves are valves with cylindrical or conically tapered "plugs" which can be rotated inside the valve body to control flow through the valve. The...
quarter-turn valves include the butterfly valve and plugvalve and freeze proof ball valve. There are five general body styles of ball valves: single body...
internal parts of a valve, a user would take off the bonnet, usually for maintenance. Many valves do not have bonnets; for example, plugvalves usually do not...
A globe valve, different from ball valve, is a type of valve used for regulating flow in a pipeline, consisting of a movable plug or disc element and...
valves use a different plug (core) using either an internal ball bearing or a spring-loaded rubber plug that is unseated by pumping, making the valve...
cross-section, and a plug, usually a disk shape on the end of a shaft known as a valve stem. The working end of this plug, the valve face, is typically...
recovery coefficient. Examples: butterfly valve, ball valve, plugvalve, gate valve Low recovery valve: These valves typically regain little of the static...
tamper-proof spring safety valve that became universal on railways. The Ramsbottom valve consisted of two plug-type valves connected to each other by...
the outside of the cage rather than a plug inside the cage. A choke may also include a conical valve and valve seat, to ensure complete shutoff. Fluids...
valve Globe valve Mass flow controller Plastic pressure pipe systems Plugvalve Ward, L.; Bunn, J.P. (1967). Introduction to the Theory and Practice of...
A conical plugvalve is spring-loaded. Flow around this valve acts against spring pressure. Flow of liquid is sufficient to hold the valve against the...
A rotary valve (also called rotary-motion valve) is a type of valve in which the rotation of a passage or passages in a transverse plug regulates the flow...
at stopcock valves and ground glass joints to provide a gas tight seal and prevent glass pieces from fusing. In contrast, teflon plugvalves may have a...
Piston valve (steam engine) Plugvalve, slim valve for on–off control but with some pressure drop Solenoid valve, an electrically actuated valve for hydraulic...
pressure is transferred to the valve stem, which is connected to either the valveplug (see plugvalve), butterfly valve etc. Larger forces are required...
blowoff valve (also called dump valve or compressor bypass valve) is a pressure release system present in most petrol turbocharged engines. Blowoff valves are...
the valve stationary unless there is a backup power supply. A typical representative of the valves to be automated is a plug-type control valve. Just...
to the engine's valves, working the cycle of steam and injection water valves to operate the engine. This operation by tappets on a plug rod continued into...
AC power plugs and sockets connect devices to mains electricity to supply them with electrical power. A plug is the connector attached to an electrically-operated...
designed as an ultimate fail-safe. Such safety valves traditionally used a simple lever to restrain a plugvalve in the top of a boiler. One end of the lever...
8 cu in) displacement 90-degree V8 has been offered in 2-valve SOHC, 3-valve SOHC, and 4-valve DOHC versions. The engines were also offered with both aluminum...
travels to the spark plug (via high tension leads), where it ignites the air-fuel mixture in the combustion chamber. On most overhead valve engines, the distributor...
movable rod positioned in front of the nozzle. The plug looks similar to a poppet valve. The stem of the valve runs back through the body of the nozzle body...
A banana connector (commonly banana plug for the male, banana jack (or socket) for the female) is a single-wire (one conductor) electrical connector used...
have plugvalves with conically-tapered inserts called stopcocks (sometimes referred to as "plugs" by laypeople) with different bores. The valve bodies...
A thread T-bore plugvalve used as a side arm on a Schlenk flask. A common straight bore glass stopcock attached with a plastic plug retainer in the side...
Global Information
