Analysis of the principle of the swing check valve

The swing-type check valve adopts the built-in rocker swinging type structure. All the opening and closing parts of the valve are installed outside the valve body, and do not penetrate the valve body. Except for the sealing flange and the sealing ring of the middle flange part, none of them External leakage point, the possibility of leaking the valve. The swinging check valve has a spherical joint structure at the rocker arm and the valve disc joint, so that the valve flap has a certain degree of freedom in the range of 360 degrees, and has appropriate micro-position compensation.

The role of this type of valve is to only allow the media to move in one direction and prevent the direction from moving. Usually, the valve is self-opening, and the valve flap is opened under the action of the fluid pressure in one direction; when the fluid moves in the opposite direction, the fluid pressure and the self-reclosing valve flap of the valve disc act on the valve seat, thereby cutting off the activity. . Among them, the cast iron swing check valve belongs to this type of valve, and includes a swing check valve and a lift check valve. The swing check valve has a hinge mechanism and a door-like flap that rests freely on the outer surface of the tilted seat. Flange gate valve In order to ensure that the valve flap can reach the proper position of the valve seat surface every time, the valve flap is designed in the hinge mechanism, so that the valve flap has enough swinging space and the valve flap is true and one-sidedly in contact with the valve seat. The flaps can all be made of metal, or they can be inlaid with leather, rubber, or perhaps with a masked surface, depending on the functional requirements.

When the swing check valve is fully opened, the fluid pressure is simply unobstructed, and the pressure through the valve becomes smaller. The valve flap of the lift check valve is located on the valve seat sealing surface of the valve body. In addition to the 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 medium return causes the valve flap to fall back to the valve seat and cut off the activity. Depending on the application conditions, the valve flap can be an all-metal construction or 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 greater than that of the swing check valve, and the flow of the swing check valve is encountered. There are very few restrictions.