Main Structural Features：
1. Compact structure, small bulk, good rigidity, safety and reliability.
2. Design and manufacture according to ANSI B16.34, API 600 and API 6D.
3. Valve seat is renewable, which may combine and match sealing face of closure parts at random to meet job condition and extend usage time.
4. Closure parts (Wedge) adopt flexible structure and can automatically compensate for body distortion resulting in abnormal load or temperature. So it has reliable sealing and to avoid wedge clamped.