Types of Valves

Valves are the very important for any piping system. Without valves it’s impossible  to run piping system. Valves are extensively used in piping system to Interrupt or Divert or regulate the flow of fluids. Various types of valves with their function are mentioned below.

Type of valve base on bore includes:
    Full Bore Valve :- A full bore valve has an over sized ball so that the hole in the ball is the same size as the ID of the pipe. Full bore valves normally used in piggable line since allowing cleaning pig traverse. Full bore valves can be used in flow meter applications to minimize fluid turbulence upstream of the measuring device.

    Reduced Bore Valve:- The reduced bore valve has hole through the ball smaller than the ID of the pipe resulting in restricted flow.

    Type of end connection of valve includes:

    • RF/RTJ
    • Nipple both ends
    • Female both ends
    • Nipple end x Female end
    Types of Valves
    • Gate valve
    • Ball Valve
    • Globe valve
    • Butterfly Valve
    • Check valve
    • Plug Valve
    • Safety valve/Relief Valve
    • Diaphragm Valve
    • Needle valve
    • Control Valve

    Gate Valves

    Gate valves are primarily designed to serve as isolation valves. In service, these valves generally are either fully open or fully closed. When fully open, the fluid or gas flows through the valve in a straight line with very little resistance As a result, the pressure loss through the valve is minimal. Gate valves should not be used in the regulation or throttling of flow because accurate control is not possible. Furthermore, high flow velocity in partially opened valves may cause erosion of the disks and seating surfaces. Vibration may also result in chattering of the partially opened valve disk.
    Gate Valve

    Gate Valve installed where an uninterrupted flow is required. When the valve is in an open position, the gate fully retracts into the bonnet - completely removed from the flow stream, creating a minimal pressure drop

    Gate valves consist of three major components: body, bonnet, and trim. The body is generally connected to the piping by means of flanged, screwed, or welded connections. The bonnet, containing the moving parts, is joined to the body, generally with bolts, to permit cleaning and maintenance. The valve trim consists of the stem, the gate, the wedge, or disk and the seat rings.

    It is the most commonly & very widely used valve in industrial piping for isolation of the flow. It is manually operated and it is not recommended for regulation of the flow. Installation of this valve is possible from both the ends. Hence it is bi-directional valve.

    1 End Preparation:

    • Cast Steel valves have Flanged or Butt weld end preparation.
    • Forged Steel valves have Socket weld or Threaded end preparation.

    2 Design & Dimension Standard:

       The dimension Standard for gate valve is as follows.
    • API 600 For Cast Steel valves (Flanged/BW valves)
    • API 602 Forged Steel valves (SW/Threaded valves)
    • ANSI B 16.34 For Pressure & Temperature limitation & Rating
    • ANSI B 16.10 For face to face dimension of Flanged & BW end
    • API 598 For Testing of valve

    3 Main parts: Gate valve has following main parts.
    • Body
    • Bonnet
    • Internals/Trim/Wetted parts: Parts that come in direct contact with the fluid. Gate valve has
    • following Internals/Trim/Wetted parts.
    • Wedge / Seat Ring / Stem / Gland Bush

    4 Pressure Class:
    • There are 150,300,600,900,1500,2500 ratings for Flanged & BW valve.
    • There is 800 rating for SW or Threaded valve.

    4      Material:           Forged Steel                              Cast Steel
     CS             ASTM A 105                                ASTM A 216 Gr WCB
    LTCS          ASTM A 350 Gr LF2                        ASTM A 352 Gr LCB
    LAS            ASTM A 182 Gr F11                        ASTM A 217 Gr WC6
    ASTM A 182 Gr F22                        ASTM A 217 Gr WC9
    ASTM A 182 Gr F9

       SS           ASTM A 182 Gr F304                       ASTM A 351 Gr CF8
    ASTM A 182 Gr F304L                     ASTM A 351 Gr CF8M
    ASTM A 182 Gr F316                       ASTM A 351 Gr CF3M
    ASTM A 182 Gr F316L                     ASTM A 351 Gr CF3C
    ASTM A 182 Gr F321

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