The thickness of the hot rolled Galvanized Steel Coil 0.2-1.5mm,width 800`1250mm,can achieve equal thickness and differential plating thickness,surface structure haveing zero zinc flwer ,small zinc flower,finishing zinc flower , surface treatments are oil ,oil plus passivation ,passivation,environmental protection passivating print resistant etc. Galvanized Coil,Galvanized Steel Coil,Hot Rolled Galvanized Coil,Cold Rolled Steel Coil TIANJIN ZHENXIANG STRIP PROCESSING CO., LTD. , http://www.zhenxiangsteel.com
The working principle of the welding check valve: Check valve is a valve that can automatically prevent the fluid from flowing backwards. The check valve flap opens under fluid pressure and fluid flows from the inlet side to the outlet side. When the pressure on the inlet side is lower than on the outlet side, the valve flap closes automatically under the effect of fluid pressure difference and gravity itself to prevent fluid backflow. Welding check valve classification: Welding check valve is generally divided into lifting, swing-type, and so on several types. Lift check valve structure generally similar to the cut-off valve, the valve flap along the centerline for lifting movements, reliable action, but the fluid resistance larger, suitable for smaller caliber occasions. Lift check valve can be divided into straight and vertical two. Straight-through lift check valve can only be installed in the horizontal pipe, and vertical lift check valve should be installed in the vertical pipe. Swing check valve flap for rotation around the axis of rotation. The fluid resistance is generally less than the lift check valve, which is suitable for larger diameter occasions. Swing check valve according to the number of valves can be divided into single-valve swing type, double-swing type and multi-swing swing type three. Single-flap swing check valve is generally suitable for medium-diameter occasions. Selection of large-diameter pipe single swing check valve, in order to reduce water hammer pressure, it is best to reduce the pressure of the water hammer slow closing check valve. Double valve swing check valve for medium and large diameter pipe. The double-flap swing check valve has the advantages of small structure and light weight, and is a fast-developing check valve. The multi-valve swing check valve is suitable for large-diameter pipelines.