The ENARDO Series 2100 is designed to provide an emergency pressure relief opening for storage tanks when exposed to over pressures that are not handled by standard tank vents. These vents provide the capacity to meet API standard 2000 for emergency venting due to fire exposure when properly sized. Quick and easy access for tank inspection and maintenance is also provided. The Enardo emergency pressure relief vent provides pressure relief only. Vacuum relief must be supplied by normal venting devices or an Enardo Series 2500 emergency relief vent with vacuum. When excessive pressure builds within the storage tank the Series 2100 Emergency Pressure Relief Vent lid begins to open at the predetermined set pressure, relieving excess pressure. When the over-pressure has dissipated the cover reseats onto the base. Guides prevent misalignment and provide an accurate reseat.