버터플라이 밸브는 표면 사이의 거리가 다른 범용 밸브보다 짧으며, COMPACT하기 때문에 중량이 가볍고 설치가 용이하다.볼밸브, 플러그 밸브와 마찬 가지로 90도 회전 밸브이다. 주로 저압배관에 많이 사용된다.배관연결방방식은 Wafer, Flange, Lug 형식등이 있다.
The valve body shall be one piece cast. The valve can be supplid with different type of materials in wafer, lug, and flanged or butt welding and connections to satisfy all installation requirements.
The valve disc shall be the same material as the valve body. It is supported by laminated sealring, which is kept in place by seat retainer ring bolted to the disc and can be replaced easily.
■ BODY SEAT
The valve seat shall be integrated with the body. Stellite or stainless steel shall be applied on the seating surface of valve body.The valve seat is designed for inclined cone to ensure non-rubbing, non jamming, bi-directional shut-off, and zero leakage.
■ SEAL RING (LAMINATED)
The seal ring shall be resilient stainless steel lamella alternated by graphite, aramid fiber & ceramic fiber layers. The surface contacting between seal ring and body seat is an inclined cone type and the inclined angle generates a slight wedging effect.
The heat-treated stem of one piece and two piece construction insure adequate mechanical properties and surface hardness. Friction at the time of opening and closing is reduced to a minimum friction to accurate machining and lapping. The stem shall be fixed to the disc by pin or combination of pin and key. The thrust bush and bearing shall be provided to locate the valve disc in a proper position.
The packing shall be consist of two braided rings in the top and bottom of valve and three die formed graphite rings in the middle. The lantern ring may be provided as required by customer.
Electric, pneumatic or hydraulic actuator may be provided as required by customer