1991 Hurst Tubeless Vertical Boiler- 10 HP. Model: 4VT Cyclone. S/N: V49-150-25. Nat'l Bd: 1111. Steam output: 345 lbs/hr. Input required: 418,000 Btuh. Firing rate (natural gas): 215 cu. ft./hr. Water capacity @ nominal water level: 48 gal. Water capacity flooded: 68 gal. MAWP: 150 psi. Heating surface area: 49 sq. ft. Burner, Model S6, electrical requirements: 120V, 5.0 ams, 60 Hz, single phase. Blower Motor, 3/4 hp, 3450 rpm, 115/230 V, 12.4/6.2 amps, 60 Hz, 3 phase. The Hurst boiler's four-pass, high pressure design allows the gases that are leaving the furnace to be split though four individual serpentine fin passages to the stack outlet. Heat transfers evenly to the fins and boiler shell, eliminating the metal stress due to uneven heat transfer. Compact sized unit produces drier steam. Inlets: (1) 1/2 in. dia. NPT (male, gas), (1) 1 in. dia. bevel with hex nut (water). Outlets: (1) 3/4 in. dia. NPT (male, steam), (1) 8 in. dia. vent stack. Overall dimensions: 72 in. L x 52 in. W x 72 in. H.(H15).