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  2. 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.

  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. 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 ...

  5. Relief valve - Wikipedia

    en.wikipedia.org/wiki/Relief_valve

    A relief valve DN25 on cooling water pipe from heat exchanger Schematic diagram of a conventional spring-loaded pressure relief valve. A relief valve or pressure relief valve (PRV) is a type of safety valve used to control or limit the pressure in a system; excessive pressure might otherwise build up and create a process upset, instrument or equipment failure, explosion, or fire.

  6. Pilot-operated relief valve - Wikipedia

    en.wikipedia.org/wiki/Pilot-operated_relief_valve

    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. Snap acting At set pressure the valve snaps to full lift.

  7. Downhole safety valve - Wikipedia

    en.wikipedia.org/wiki/Downhole_safety_valve

    This means that they are installed as a component of the completion string and run in during completion. Retrieving the valve, should it malfunction, requires a workover. The full name for this most common type of downhole safety valve is a Tubing Retrievable Surface Controlled Sub-Surface Valve, shortened in completion diagrams to TRSCSSV.

  8. 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 ]

  9. Pipe-in-pipe system - Wikipedia

    en.wikipedia.org/wiki/Pipe-in-pipe_system

    A water distribution cabinet with a pipe-in-pipe system. Internal pipes can be seen entering the external pipes in the bottom of the cabinet. In case of an internal leak, water will overflow through the external piping and can be detected inside the cabinet. A pipe-in-pipe system [1] is a form of plumbing where all water pipes are running ...