Special Variation – 3.5″ Push Vent with 4″ Sump Flange

The Betts’ special 3.5″ Push Vent with 4″ Sump Flange provides positive venting for bottom loading or unloading a cargo tank and is designated as a vapor recovery valve.  This push vent has a reduced 3.5″ diameter disc, yet offers the larger 4″ sump mounting flange.

The vapor recovery valve mounts to a standard 4″ sump and must be located directly above the emergency valve and in an area protected by the tank’s rollover damage protection device (overturn rails).  The vapor recovery valve is mechanically actuated via a push rod extending from the top of the emergency valve.

The vapor recovery valve should have an emission collection hood securely mounted to the vapor valve flange.  The outlet of the hood should be connected to the vapor collection system of the cargo tank to ensure a closed loop system that contains all vapors.  See section 24 page 1A for emission collection hoods.

The vapor recovery valve is constructed of aluminum with stainless steel trim.  The assembly includes a threaded adjustment fitting, a 60” aluminum push rod and an adapter to fit up with the Emergency Valve.