The arrow on the body should match the direction of flow of the working medium.
Install the flanged check valves close to the valve body - it is not recommended to install them too far away as it can interfere with the opening of the valve flap. There are no such restrictions for valves in flanged and sleeve execution.
To diagnose failure before and after the check valve, it is recommended to install pressure gauges.
An un-sprung valve can only be installed on a horizontal pipeline or a vertical one with the flow going from bottom to top.
The body of the flanged and sleeve check valve should not be subjected to twisting, stretching, or compression loads from connected pipelines.
The presence of mechanical inclusions in the flow can disrupt the shut-off function of check valves of all types except for the ball valve, so it is recommended to install a filter before valves of other types.
Before installing a check valve, the pipeline should be thoroughly flushed from mechanical inclusions.