Summary of valve and pipeline connection

  • Including the common way to connect the valve: flange on the clip connections, welded connections, threaded connections, the card sets of connections, clamp connections, self sealing connections to connect the form.
    1, the flange connection
    Flange connection is provided with flanges at both ends of the valve body, and the corresponding pipe flange, installed in the pipeline flange by bolts. Valve flange connection is connected with most forms. A convex flange (RF), flat (FF), the convex and concave surface (MF) of points. By combining surface shape can be divided into the following categories:
    1) smooth type: for the low pressure valve. More convenient processing
    2) concave convex type: high working pressure, can be used in hard washer
    3) tongue and groove: the larger plastic deformation can be used washer, is widely used in the corrosive medium, better sealing effect.
    4) trapezoidal trough: use the elliptical metal ring gasket, used in the working pressure greater than or equal to 64 kg / square cm of the valve, or high temperature valve.
    5) lens: lens gasket is shape, with metal production. For a 100 kg / cm2 high-pressure valve working pressure ≥, or high temperature valve.
    6) O ring type: This is a relatively new form of the flange connection, it is with the emergence of various rubber O ring, and developed, its effect on the sealing gasket and reliable than the general level.
    Common thread has five categories: metric common thread; inch screw thread pipe thread; sealing; non thread sealing pipe threads; American Standard Pipe thread.
    Briefly introduced as follows:
    International standard ISO228/1, DIN259, for internal and external parallel threads, code named G or PF (BSP.F);
    The German standard ISO7/1, DIN2999, BS21, as the outer tooth cone, inner tooth parallel threads, code named BSP.P or RP/PS;
    The British standard ISO7/1, BS21, inner and outer conical thread, code named PT or BSP.Tr or Rc;
    The American Standard ANSI B21, inner and outer conical thread, code named NPT
    G (PF), RP (PS), Rc (PT) tooth type angle is 55 °, NPT tooth type angle is 60 °
    BSP.F, BSP.P and BSP.Tr are collectively referred to as BSP teeth.