1. Design and manufacture of product according to ANSI B16.34 and API600 and API 6D. 2. Compact structure, small bulk, perfect rigidity, safety and reliable. 3. Blow down part (disc) utilize flexible structure, can automatically compensate distortion of body due to abnormal burden or temperature,so seal reliable and prevent wedge disc being blocked. 4. Manual valve with size over or equal to NPS 10", class 150 pounds and size over or equal to NPS6", class 600~2500 pound equip with roller bearing to operate easily. 5. Material of main body. Material of trims, packing, washer, material of fastener can logically combine according to customers requirement or actual work status. 6. Exchangeable inside thread seat is used for NPS≿0" gate valve, random combine the material of surface of blow down part to meet the requirement of work status, prolong service life.