What is a soft-back butterfly valve?

The soft-back butterfly valve has a very small and light torque, is flexible to rotate, easy to open and close, and the rubber part can be easily removed for future maintenance and replacement. It has a good appearance and workmanship. The soft-back butterfly valve has a simple structure, is small in size, light in weight, and is composed of only a few parts. It can be quickly opened and closed by rotating 90 degrees, and the operation is simple. At the same time, this valve has good fluid control characteristics. When the butterfly valve is in the fully open position, the thickness of the butterfly disc is the resistance of the medium flowing through the valve body, so the pressure drop produced by this valve is very small, thus having good flow control characteristics. The butterfly valve has a small volume and occupies little space. The sealing performance is good. When choosing, it is still based on the medium, temperature, pressure, etc. For the flanged butterfly valve, the installation is done by using double-headed bolts to connect the valve between two pipe flanges.

The soft-back and hard-back of the butterfly valve both refer to the valve seat of the soft-sealing butterfly valve. Both valve seats can achieve zero leakage. In terms of price, the hard-back valve seat is slightly cheaper. The rubber valve seat of the soft-sealing butterfly valve can be divided into hard-back rubber valve seat and soft-back rubber valve seat. The difference is that the hard-back valve seat is pressed onto the valve body by a mold and is not easy to be replaced, and the edge of the hard-back valve seat is thinner and cannot be recycled. The soft-back valve seat is manufactured according to the model and is easy to replace. The edge of the soft-back valve seat is wider, and non-specific flanges can be used when connecting the pipe and the valve, and the sealing performance is as good as that of the flange connection. The selected rubber material is also wear-resistant new rubber, and it can be recycled after damage. In terms of the service life of the rubber valve seat, the service life of the soft-back valve seat is longer than that of the hard-back valve seat. The soft-back valve seat belongs to a wide-edge structure. During the long-term operation of the valve, the valve seat axis end is worn. When water leaks from the valve seat axis end, the water directly seeps out of the valve body and causes an external leakage phenomenon. However, the soft-back valve will not have this situation.

The structural characteristics of the soft-back butterfly valve:

1. The butterfly valve has the characteristics of a simple structure, small size, light weight, low material consumption, small installation size, rapid opening and closing, 90-degree reciprocating rotation, and small driving torque. It is used to cut off, connect, and regulate the medium in the pipeline, and has good fluid control characteristics and closing sealing performance.

2. The butterfly valve can transport slurry, and there is little liquid accumulation at the pipe opening. Good sealing can be achieved under low pressure, and the regulating performance is good.

3. The streamlined design of the butterfly disc makes the resistance loss of the fluid small, and it is an energy-saving product.

4. The valve stem is a through-bar structure, and it is treated by quenching and tempering, having good comprehensive mechanical properties and corrosion resistance, and anti-abrasion. When the butterfly valve is opened and closed, the valve stem only rotates without lifting and lowering movement. The packing of the valve stem is not easily damaged, and the seal is reliable. It is fixed by the cone pin of the butterfly disc, and the extended end is designed to prevent it from being pushed out in case of accidental fracture at the connection point between the valve stem and the butterfly disc.