VIAIR 1/2 Gallon Air Tank This compact 1/2 gallon air tank is rated at 150 PSI, is continuously welded, and internally and externally coated for corrosion resistance. With Two 1/4 NPT female ports, The tank can be mounted in many positions for installation of safety valves, pressure switches, and drains without the use of costly manifolds. All mounting hardware included. 5 long x 6 diameter. Silver finish.