(1) structure is simpler than gate valves manufacture and maintenance more convenient.

(2) seal surface is not easy to thread stop valves

(1) structure is simpler than gate valves manufacture and maintenance more convenient.

(2) the seal easy to wear and abrasion, well sealed, open and close the disc and no relative slip between the sealing surfaces of the valve body, wear and scratches are not serious, good sealing performance and long service life. (3) when opening and closing, valve flap small, thus the valve height smaller than the valve, but the structure of length longer than the gate.

(4) large torque, opening and closing effortless, opening and closing time of the headmaster.