SEQUENTIAL VAPOR VENT FOR MANHOLES Existing customers can log in to their account for additional savings Call for price Categories: Tank Truck Equipment, Chemical, Chemical Tank Truck Parts, Liquid - Petroleum, Petroleum Tanks Truck Parts Description Specification Description Use: – For 16″, 20″ manhole, with thread mounting ring Features: – Any necessary maintenance is easy to perform Construction: – Rugged cast aluminum Installation: – Can be installed to open in sequence with another pneumatically controlled device such as the emergency valve, or open independently by simply plugging the lower of the 2 ports (use a 1/4″ male NPT plug) Specifications Part # VR3030SQ VR3035SQ Related products Pail Lids / Ring Clamps Pails – Cable & Clamp Attached Aluminum WD Valve – Standard Dry Bulk – Air Pressure Relief Valves