Shutoff valves

The shutoff valves serve for cutting off of intra room distributing from struts for the period of carrying out repair work or elimination of an emergency. Still quite recently as shutoff valves cranes with a valve head which operation is based on reciprocating or rotary progress were used almost only. In knots of such cranes the condensing function is carried out by an epiploon and rubber laying. The main lack of cranes with a valve head is their low reliability - they quickly fail due to wear of epiploons or breakage of screws. And such phenomenon as "increment" to a pipe, can complicate considerably, or absolutely make impossible use of shutoff valves.
Now cranes with a valve head even more often are succeeded by spherical cranes - convenient, reliable and durable. They are obliged by the name to a form of the locking rod - the sphere with a cylindrical opening made of the polished metal. The condensing ftoroplastovy laying provides full tightness of the crane. A resource of such crane - 10 thousand cycles.
But at installation of the spherical crane it is necessary to remember that in the market cheap samples which will quickly fail meet. Therefore, you should not save on quality, - Bagatti (Germany) or Tiemme (Italy) is better to acquire production of the famous producers, for example.