Fully welded axial flow check valves can be used in industrial fields such as crude oil, refined oil, natural gas, gas, oxygen, chemicals, light industry, and urban sewage. All welded axial flow check valves have Class 150~Class2500 and PN10~PN420; the valve specifications are DN25~DN1200; the valve body materials are carbon steel, alloy steel and stainless steel. The main features of the all-welded axial flow check valve are as follows: 1. The whole body of the valve body is forged into a standard spherical shape, and even under complicated stress conditions, the best deformation resistance is obtained. 2. The valve body adopts narrow gap submerged arc automatic welding (all welding) without any external leakage. 3, streamlined flow channel design, small flow resistance, good flow. 4. The ball valve is supported at the front and rear ends, and there is no jamming on the opening and closing, and the operation is reliable. 5. Precise spring design ensures low pressure sealing and low pressure opening. 6, valve seat double seal design, "zero" leakage. 7. Compact structure, small size and valve can be installed at any angle. 8, low noise, energy saving and environmental protection. 9. Wide application range, the valve seat can be designed as soft or hard seal according to requirements.