Justrite safety drum vents provide emergency pressure venting in the event of a fire to avoid drum failure and catastrophic consequences. All safety drum vents automatically relieve pressure between 3 and 8 psi (30 to 55kPa) and include a flame arrester to absorb and safely dissipate heat. A valve within the vent is tested to allow 61 cubic inch (1-L) of water through a 3/8-in (9.5-mm) pipe nipple in less than 6 seconds for vacuum relief during drum dispensing operations. This permits smooth liquid flow and prevents the possible drum collapse and leakage. The vacuum relief is automatic on vertically-installed vents and manual on horizontally-installed vents.