Swing check valve description

Swing check valves are widely used in pipeline transportation such as petrochemical, pharmaceutical, and electric power. In these systems it is often necessary to transport some oil, steam, nitric acid, and highly oxidizing media. The swing check valve is constructed by an internal rocker swinging structure to prevent these media from back flow and to avoid internal media outflow.

The swing check valve is used in the transportation control of the piping system, like the lift check valve. However, lift check valves can only be used in horizontal pipes, while swing check valves can be installed either in horizontal pipes or in vertical pipes. However, the swing check valve and the lift check valve work in the same way, and the action of the pressure generated by the flow of the medium and the pressure of the flap itself act. Generally, the inlet direction of the internal medium flow can impact the flap. Turn to the other side.

The swing check valve mainly consists of a valve body, a valve cover, a valve flap and a rocker. In addition, there are auxiliary springs and heavy hammer structures to improve the tightness of the pipeline, because in the low pressure condition, the rotary The sealing of the open check valve is not sufficient.

The metal seat of the swing check valve is often prone to wear, and the internal pressure of the swing check valve exceeds the pressure drop of the valve check valve. Therefore, a damping structure is arranged on the valve flap inside the check valve to avoid the fact that when the medium in the pipeline flows, the valve flap is suddenly closed due to the lifting and lowering of the check valve, so that a water hammer is generated in the pipeline, causing wear on the valve seat. .

The swing check valve controls the swirling flow in the pipe through the internal flap and the rocker shaft. The passages in the valve are streamlined and, therefore, produce more powerful flow resistance. Because of the gravitational force of the flap, the swing check valve opens, creating resistance to the flowing medium.

When the swing check valve is installed in a vertical pipe, the internal medium in the pipe flows from bottom to top. If an emergency stop occurs, the internal valve will flow back into the pipe together with the internal medium due to its own gravity. At the same time, the internal valve will also automatically close, playing a command role. When the swing check valve is installed in a horizontal pipe, the internal medium in the pipe can be automatically closed by flowing in a single direction.

In short, the swing-type check valve is used as an automatic device. All the internal opening and closing devices act on the inside of the valve and do not penetrate the valve body. This avoids the possibility of leakage of the pipe liquid. The valve flap is made through the spherical connection structure. It can maintain a certain degree of freedom and achieve a longer service life.