Used Pope Scientific 20 gallon 316L stainless steel jacketed pressure tank. Unit is rated for 95 PSI max working pressure, 40 PSI @ 100 deg F on jacket. Tank measures 18" dia x 20" deep with 2-1/2" top inlet, 4" center bottom discharge. Jacket has 1/2" inlet and outlet. Serial number 59659-001, mfg new 1995, on casters.