The butterfly valve is a butterfly plate that rotates with the valve stem as the opening and closing part to realize the opening, closing and adjustment of the valve. In addition to the start-up and shut-off of butterfly valves in the pipeline, the sealing performance has been taken as the main index of evaluation in recent years, which is favored by the market. In addition, the butterfly valve has the advantages of small volume, light weight and simple structure. Compared with the gate valve with the same parameters, the average accumulated weight is 30 ~ 50%. The opening and closing process can be realized by rotating the butterfly plate by 90 °. In addition, since the force of medium on both sides of the rotating shaft is approximately equal, the torque is opposite, so the opening and closing torque is small.

1. There are two basic types: flange type and wafer type (center line) fully lined wafer type butterfly valve. The valve body is combined with two-piece valve body. The valve seat and the valve body lining are integrated. When the valve is working, only the fully plastic valve seat and the plastic lined butterfly plate are in contact with the medium. The product can withstand any medium corrosion except the molten alkali metal and elemental fluorine. The valve stem and the butterfly plate (forged) of the butterfly valve are integrated, and the surface is evenly coated with FEP. The inner surface of the valve body channel is smooth, the fluid resistance is small, the CV value is high, the flow capacity is strong, and the torque is moderate. The four-stage sealing structure is adopted and the elastic gasket valve seat of temperature resistant and aging resistant Si rubber is equipped outside the sealing surface, so as to completely achieve zero leakage of the medium.

2. For the flange type and wafer type semi Lined Butterfly Valves expanded from the above models, the inner parts of the butterfly plate and the valve stem are not lined and are made of corrosion-resistant stainless steel; The valve body is fully lined. This structure is called semi lined butterfly valve.

Structural features

1. The center line butterfly valve is that the whole butterfly plate and the butterfly seat are concentric (center line) within the 360 ° circle, with two-way sealing function, and the pressure and flow can be freely adjusted;

2. Four stage loading elastic seal, absolutely ensuring zero leakage inside and outside the valve;

A. Reasonable interference between the special transition curve at the circumferential connection of the shaft head and the butterfly plate and the valve seat;

B. The end face of the shaft head is composed of an elastic O-ring, a rigid washer and an elastic rubber pad at the shaft shoulder;

C. The radial direction of the shaft adopts the combination of O-ring and metal pad;

D. The valve seat is embedded in the elastic valve body groove;

3. The adjustable elastic pin is used for positioning, with accurate positioning and simple structure.