Pneumatic valves threaded connection form standard

threaded connection is the main connection way small pneumatic valves, pneumatic thread lock pneumatic valve, ball valve, the thread by the pneumatic valve and check the pneumatic valve. Threaded connection is a simple connection method. Pneumatic valve body, according to the standard of the thread processing, has two kinds of female and male. And pipe thread on correspondence.
threaded connection in two situations:
and direct seal: internal and external screw thread sealing effect directly. In order to ensure that joint not leak, often filled with lead, cotton and ramie thread woven and ptfe teflon tape; The ptfe teflon tape, became more and more widely used; The corrosion resistance of the material is very good, good sealing effect, easy to use and preservation, remove, can be fully removed, it because it is a layer non-viscous film, much more superior than lead, cotton and ramie thread woven.
and indirect seal: the power of the screw tight, passed between two flat washer, gasket sealing role.
common thread has five categories: metric common thread; English common thread; Thread sealing tube; The thread sealing tube; American standard pipe thread.
thread standard overview is as follows:
, the international standard ISO/DIN, parallel thread for inside and outside, code or PF (G BSP。 F;
, Germany standard, ISO/DIN, BS, for within the outer conical teeth, tooth parallel threads, codenamed BSP. P or RP/PS;
, British standard, ISO/BS, inner and outer taper, codenamed PT or BSP. Tr or Rc;
, American standard ANSI B, inner and outer taper, code the NPT.
　　G( PF、RP( PS、Rc( PT tooth type Angle are °, NPT thread form Angle for °.
BSP。 F, BSP。 P and BSP. The Tr are collectively referred to as BSP teeth.
American standard pipe thread including five kinds: generally USES the taper pipe threads of NPT, pipe joint with straight pipe internal thread NPSC, guide rod connected with taper pipe threads NPTR, mechanical thread connection with straight pipe thread NPSM ( Free with mechanical connection and NPSL ( With a lock nut loose fit mechanical connection. Belongs to the thread sealing pipe thread ( N: the American national standards; P: pipe; T: conical)