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FIG 155, 155S

Double Outlet Vent

T-style open vent used primarily on small storage tanks.

NOTE: Open vents will allow unrestricted evaporation of product.

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 airflow 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.

Product Features

Standard Features

Outlet ports on either side of the airway for maximum venting

Rain resistant design

Screen helps prevent debris and insects from entering the airway

155 has female NPT threads

155S is slip-on with a set screw


Construction Details

  • Body: Aluminum
  • Screens: 20 mesh stainless steel

Product Ordering Instructions

Figure Suffix Size Description Weight (lbs)
155 0100 AV .75” Double Outlet Vent-Threaded Style 0.25
155 0200 AV 1” Double Outlet Vent-Threaded Style 0.5
155 0300 AV 1.25” Double Outlet Vent-Threaded Style 0.5
155 0400 AV 1.5” Double Outlet Vent-Threaded Style 0.75
155 0500 AV 2” Double Outlet Vent-Threaded Style 1
155BSP 0500 AV 2” Double Outlet Vent-Female British Pipe Threads 1
155 0600 AV 3” Double Outlet Vent-Threaded Style 2.5
155BSP 0600 AV 3” Double Outlet Vent-Female British Pipe Threads 2.5
155S 0100 AV .75” Double Outlet Vent-Slip On Style 0.25
155S 0200 AV 1” Double Outlet Vent-Slip On Style 0.5
155S 0300 AV 1.25” Double Outlet Vent-Slip On Style 0.5
155S 0400 AV 1.5” Double Outlet Vent-Slip On Style 0.75
155S 0500 AV 2” Double Outlet Vent-Slip On Style 1
155S 0600 AV 3” Double Outlet Vent-Slip On Style 2.5