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Emergency Vents
One Year Manufacturer Warranty

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Morrison Brothers 244O Emergency Vents

4 in. to 8 in. FNPT

Ships From Manufacturer

Select Model & Quantity:

Model # Description Price Qty
244O--0060 AV 3 in. FNPT, 16oz/sq.in. Opening Pressure Setting, with O-Ring $88.17
244O--0050 AV 3 in. FNPT, 8oz/sq.in. Opening Pressure Setting, with O-Ring $84.46
244O--0100 AV 4 in. FNPT, 8oz/sq.in. Pressure for General Use, with O-Ring $101.45
244O--0170 AV 4 in. FNPT, 16oz/sq.in. Pressure for General Use, with O-Ring $108.97
244O--0200 AV 6 in. FNPT, 8oz/sq.in. Pressure for General Use, with O-Ring $147.88
244O--0400 AV 6 in. FNPT, 16oz/sq.in. Pressure for General Use, with O-Ring $187.80
244O--0600 AV 8 in. FNPT, 8oz/sq.in. Pressure for General Use, with O-Ring $248.21
244O--0700 AV 8 in. FNPT, 16oz/sq.in. Pressure for General Use, with O-Ring $310.92
244O--0060AVEVR 3 in. FNPT, 16oz/sq.in. with O-Ring, EVR Approved $99.37
244O--0170AVEVR 4 in. FNPT, 16oz/sq.in. with O-Ring, EVR Approved $137.53
244O--0200AVEVR 6 in. FNPT, 8oz/sq.in. with O-Ring, EVR Approved $155.27
244O--0400AVEVR 6 in. FNPT, 16oz/sq.in. with O-Ring, EVR Approved $197.17
244O--0600AVEVR 8 in. FNPT, 8oz/sq.in. with O-Ring, EVR Approved $260.62
244O--0700AVEVR 8 in. FNPT, 16oz/sq.in. with O-Ring, EVR Approved $326.47
244O--0800 AV 5 in. FNPT, 8 oz. with O-Ring $141.64
244O--0900 AV 5 in. FNPT, 16 oz. with O-Ring $180.92
244O--0900AVEVR 5 in. FNPT, 16 oz. with O-Ring, EVR Approved $189.96
244OB-0100 AV 4 in. FNPT, 8oz/sq.in. BSP Threaded, with O-Ring $101.45
244OB-0170 AV 4 in. FNPT, 16oz/sq.in. BSP Threaded, with O-Ring $108.98
244OB-0200 AV 6 in. FNPT, 8oz/sq.in. BSP Threaded, with O-Ring $147.88
244OS-0050 AV 3 in. FNPT, 8oz/sq.in. with O-Ring, With Screen $111.28
244OS-0060 AV 3 in. FNPT, 16oz/sq.in. with O-Ring, With Screen $115.01
244OS-0100 AV 4 in. FNPT, 8oz/sq.in. with O-Ring, With Screen $123.25
244OS-0170 AV 4 in. FNPT, 16oz/sq.in. with O-Ring, With Screen $166.67
244OS-0170AVEVR 4 in. FNPT, 16oz/sq.in. with O-Ring, With Screen, EVR Approved $159.32
244OS-0200 AV 6 in. FNPT, 8oz/sq.in. with O-Ring, With Screen $179.63
244OS-0200AVEVR 6 in. FNPT, 8oz/sq.in. with O-Ring, With Screen, EVR Approved $186.21
244OS-0400 AV 6 in. FNPT, 16oz/sq.in. with O-Ring, With Screen $225.41
244OS-0400AVEVR 6 in. FNPT, 16oz/sq.in. with O-Ring, With Screen, EVR Approved $228.12
244OS-0800 AV 5 in. FNPT, 8oz/sq.in. with O-Ring, With Screen $154.73
244OS-0900 AV 5 in. FNPT, 16oz/sq.in. with O-Ring, With Screen $203.53
244OS-0900AVEVR 5 in. FNPT, 16oz/sq.in. with O-Ring, With Screen, EVR Approved $212.58
244OSBSP0100 AV 4 in. FNPT, 8oz/sq.in. BSP Threads, with O-Ring, With Screen $123.25
244OSBSP0200 AV 6 in. FNPT, 8oz/sq.in. BSP Threads, with O-Ring, With Screen $179.63
Contact Us
Morrison Brothers 244O Emergency Vents
Emergency vents are installed on aboveground storage tanks as a code requirement. Emergency vents provide high capacity pressure relief if the tank is exposed to fire. When the internal tank pressure reaches the opening pressure of the vent, the weighted cover moves up on the center pin allowing air to escape. When the internal tank pressure falls, the cover automatically lowers back onto the body and is automatically reset.
Fig Suffix Size Description Weight
244O 0100 AV 4" 8oz/sq.in. Emergency Vent - Female Threaded w/O-Ring- UL&ULC 10
244O 0170 AV 4" 16oz/sq.in. Emergency Vent - Female Threaded w/O-Ring -UL&ULC 18
244O 0200 AV 6" 8oz/sq.in. Emergency Vent - Female Threaded w/O-Ring, UL & ULC Listed 19
244O 0400 AV 6" 16oz/sq.in. Emergency Vent - Female Threaded w/O-Ring, UL & ULC Listed 36
244O 0600 AV 8" 8oz/sq.in. Emergency Vent - Female Threaded w/O-Ring, UL & ULC Listed 33
244O 0700 AV 8" 16oz/sq.in. Emergency Vent - Female Threaded w/O-Ring, UL & ULC Listed, 62
WARNING: DO NOT FILL OR UNLOAD FUEL FROM A STORAGE TANK UNLESS IT IS CERTAIN THAT THE TANK VENTS WILL OPERATE PROPERLY. Morrison tank vents are designed only for use on shop fabricated atmospheric tanks which have been built and tested in accordance with UL 142, NFPA 30 & 30A, and API 650 and in accordance with all applicable local, state, and federal laws. In normal operation, dust and debris can accumulate in vent openings and block air passages. Certain atmospheric conditions such as a sudden drop in temperature, below freezing temperatures, and freezing rain can cause moisture to enter the vent and freeze which can restrict internal movement of vent mechanisms and block air passages. All storage tank vent air passages must be completely free of restriction and all vent mechanisms must have free movement in order to insure proper operation. Any restriction of air flow can cause excessive pressure or vacuum to build up in the storage tank, which can result in structural damage to the tank, fuel spillage, property damage, fire, injury, and death. Monthly inspection, and immediate inspection during freezing conditions, by someone familiar with the proper operation of storage tank vents, is required to insure venting devices are functioning properly before filling or unloading a tank.