Emergency relief vent 3700

The Model 3700 manhole and emergency pressure vent provide emergency pressure relief beyond that furnished by the normal pressure vent for atmospheric and low pressure tanks, as well as providing a convenient access for tank cleaning, inspection and repair. Emergency relief valves provide relief from excessive internal pressure which may be caused by an abnormal condition, such as ruptured internal heating coils or an external fire. The Model 3700 does not provide vacuum relief and therefore vacuum relief must be supplied by the normal operating vent.