Apco ACS Combination Slow Closing Air/Vaccum Valve
The APCO Slow Closing Air/Vacuum Valve actually consists of a standard Air/Vacuum Valve mounted on top of a surge Check Unit. It is designed to eliminate critical shock conditions occurring in those installations where the operating conditions cause a regular air valve to slam closed. This slow closing feature protects the Air/Vacuum valve itself and at the same time prevents the Air/Vacuum valve from creating a surge in the pipeline by slamming shut.
This type slow closing Air/Vacuum valve should not be considered as relief for shock conditions which develop elsewhere in the system. However. actual field tests prove the surge check unit may protect the Air/Vacuum valve in cases where it may be destroyed be sever shut-off shock.
This protection far outweighs the small cost of the Surge Check Unit when you consider the tremendous field damage that can result from an Air/Vacuum valve failure.