PRESSURE RELIEF VALVES

The discharge from container pressure relief valves must be vented away from the container upward and unobstructed to the open air in a manner to prevent any impingement of escaping gas upon the container. Loose fitting rain caps must be used to prevent moisture or foreign material from entering the relief valve outlet. The size of discharge lines from pressure relief valves may not be smaller than the nominal size of the pressure relief valve outlet connection. Provision must be made for draining condensate which may accumulate in the discharge pipe. Pressure relief device equipment used on DOT containers must be inspected, repaired, or replaced according to applicable DOT regulations.