Author: Site Editor Publish Time: 2019-02-20 Origin: Site
The driving mode of swing check valve is automatic, the connection mode can be selected from flange, clip type, welding, thread, structure can be selected with swing type, sealing structure can be selected with PTFE, PPL, hard seal, pressure range PN10~ PN160, the nominal diameter is DN15-1200mm, the material can be selected from WCB, 304, 316, alloy steel and so on.
Lift check valve: the lift check valve that slide along the center line can only be installed on the horizontal pipe. On the high pressure small diameter check valve, the valve ball can be used. The shape of the lift check valve is the same as that of the shut-off valve, so its fluid resistance coefficient is large. Its structure is similar to a shut-off valve. The valve body and disc are the same as the shut off valve. The upper part of the valve flap and the lower part of the valve cover are processed with a guiding sleeve, and the valve guiding sleeve can be freely raised and lowered in the valve guiding cylinder. When the medium flows downstream, the valve flap is opened by the medium thrust. When the medium stops flowing, the valve flap is closed. The self-weight falls on the valve seat to prevent the medium from flowing back. The direction of the medium outlet passage of the straight-type lifting check valve is perpendicular to the direction of the valve seat passage. The vertical lift check valve has the same direction of the medium outlet passage and the direction of the valve seat passage, and the flow medium resistance is smaller than the straight-through type.
Swing type check valve and lift check valve:
1. Swing type check valve It adopts built-in rocker swing type structure, all the opening and closing parts of the valve are installed inside the valve body, and do not penetrate the valve. In addition to the sealing gasket and sealing ring in the middle flange part, there is no external leakage point to prevent the leakage of the valve. The swing-type check valve has a spherical connection structure at the joint of the rocker arm and the valve flap, so that the valve flap has a certain degree of freedom within a range of 360 degrees, and has appropriate micro-position compensation. Swing check valves have been widely used in chemical, metallurgical, pharmaceutical and other fields.
2. Lift check valve Its valve flap is located on the valve seat sealing surface of the valve body. In addition to the valve flap being free to lift and lower, the valve is like a shut-off valve. The fluid pressure causes the valve flap to lift from the valve seat sealing surface. The return of the medium causes the valve flap to fall back to the valve seat and shut off the flow. Depending on the conditions of use, the flap may be of an all-metal construction or may be in the form of a rubber or rubber ring on the valve disc holder. Like the shut-off valve, the passage of fluid through the lift check valve is also narrow, so the pressure drop through the lift check valve is larger than that of the swing check valve, and the flow rate of the swing check valve is very few limited.