What do you mean, handle, butterfly valve, hard back and soft back?
The butterfly valve of the handle butterfly valve is installed in the direction of the diameter of the pipe. In the butterfly valve body cylindrical channel, the disc shaped butterfly plate revolves around the axis, the rotation angle is between 0 degrees -90 degrees, when rotates to 90 degrees, the valve is fully open. This valve is mounted horizontally.Butterfly valve has an elastic seal and metal seal two types of seals. Resilient sealing valve. The sealing ring can be mounted on the valve body or attached to the periphery of the disc.The hard back is the metal seal, and the soft back is the elastic seal.
Hello, soft sealing butterfly valve is generally divided into skeleton, seat and frameless valve seat, the skeleton of the general material: resin, aluminum, iron.. Etc.. With back seat is on the back of the vulcanized rubber, without skeleton, valve seat is rubber.
My understanding is: PTFE butterfly valve is a hard back; soft rubber seat is a soft back
