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A blowdown valve (BDV) is a type of shutdown valve designed to depressurize a pressure vessel by directing vapour to a flare, vent or blowdown stack in an emergency. BDVs fail-safe to the open position upon failure of the control system. [1] The type of valve, type of actuation and performance measurement are similar to an ESD valve.
Fittings allow multiple pipes to be connected to cover longer distances, increase or decrease the size of the pipe or tube, or extend a network by branching, and make possible more complex systems than could be achieved with only individual pipes. Valves are specialized fittings that permit regulating the flow of fluid within a plumbing system.
A control valve is a valve used to control fluid flow by varying the size of the flow passage as directed by a signal from a controller. [1] This enables the direct control of flow rate and the consequential control of process quantities such as pressure, temperature, and liquid level.
A check valve, non-return valve, reflux valve, retention valve, foot valve, or one-way valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction. [1] Check valves are two-port valves, meaning they have two openings in the body, one for fluid to enter and the other for fluid to leave. There are various ...
Automatic control valves do not require an external power source, meaning that the fluid pressure is enough to open and close them. Flow control valves, a type of automatic control valve, regulate fluid flow by maintaining a predetermined flow rate, independent of variations in system pressure.
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 ...
Saddle valve: where allowed, is used to tap a pipe for a low-flow need; Schrader valve: holds the air inside automobile tires; Security valve, a type of automatic shut-off valve (ASV): used to stop the flow of natural gas upon sudden pressure changes. Increased pressure or decreased pressure closes the valve (without using any external power ...
The pressure at which the control pilot relieves is the functional set pressure of the PORV. When the pilot valve reaches set pressure it opens and releases the pressure from the dome. The piston is then free to open and the main valve exhausts the system fluid. The control pilot opens either to the main valve exhaust pipe or to atmosphere ...