1184 AV45 AIR VOLUME CONTROL | Used in jet pump water systems. Maintains proper charge in conventional tanks. Prolongs pump life by reducing frequency of cycling. No AV-45 80 Maximum Tank Gallons, 1/4 in FIP. No AV-100 100 Maximum Tank Gallons, 3/8 in FIP. 42 Maximum Tank Gallons, 1/4 in FIP.