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  2. Pigging - Wikipedia

    en.wikipedia.org/wiki/Pigging

    Unlock and open, then close and relock the vent and drain valves. Unlock and open door, load pig into launcher, close and lock door. Unlock and open valves V1 and V3, to create a flow path through the launcher. Partly close ‘kicker’ valve V2 to launch the pig. The launch alarm XA will indicate when the pig has been launched. Open valve V2 ...

  3. Shutdown valve - Wikipedia

    en.wikipedia.org/wiki/Shutdown_valve

    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.

  4. Valve actuator - Wikipedia

    en.wikipedia.org/wiki/Valve_actuator

    The blue valve body is visible in-line with the pipe. The valve actuator opens or closes the butterfly disc of the valve based on electrical signals sent to the actuator. Another valve actuator is visible in the background, with windows to indicate the valve position. A valve actuator is the mechanism for opening and closing a valve. Manually ...

  5. Piping and plumbing fitting - Wikipedia

    en.wikipedia.org/wiki/Piping_and_plumbing_fitting

    Valves stop (or regulate) the flow of liquids or gases. They are categorized by application, such as isolation, throttling, and non-return. Isolation valves temporarily disconnect part of a piping system to allow maintenance or repair, for example. Isolation valves are typically left in either a fully open or closed position.

  6. Piping and instrumentation diagram - Wikipedia

    en.wikipedia.org/wiki/Piping_and_instrumentation...

    Double pipe heat exchanger Fixed straight tubes heat exchanger: U-shaped tubes heat exchanger Spiral heat exchanger Covered gas vent Curved gas vent Air filter: Funnel or tundish: Steam trap: Viewing glass Pressure reducing valve: Valve: Gate valve: Control valve: Manual valve Check valve: Needle valve: Butterfly valve: Diaphragm valve: Ball ...

  7. Partial stroke testing - Wikipedia

    en.wikipedia.org/wiki/Partial_stroke_testing

    Partial stroke testing (or PST) is a technique used in a control system to allow the user to test a percentage of the possible failure modes of a shut down valve without the need to physically close the valve. PST is used to assist in determining that the safety function will operate on demand.

  8. Hydraulically activated pipeline pigging - Wikipedia

    en.wikipedia.org/wiki/Hydraulically_Activated...

    Hydraulically activated pipeline pigging (HAPP) is a pigging technology applied for pipeline cleaning. The basic principle is that a pressure drop is created over a by-passable pig held back against a pipeline's fluid flow. The pipeline fluid passing through the pig's cleaning head is accelerated by this pressure drop, forming strong cleaning jets.

  9. Isolation valve - Wikipedia

    en.wikipedia.org/wiki/Isolation_valve

    An isolation valve is a valve in a fluid handling system that stops the flow of process media to a given location, usually for maintenance or safety purposes. [1] They can also be used to provide flow logic (selecting one flow path versus another), and to connect external equipment to a system. [2]