Temp Setting (°F) Inlet Pipe Dia. Outlet Pipe Dia. Return Pipe Dia. Dimensions Shipping Weight (lbs)*** BTH/HR GPH A B C D E Standard ASME 71E 68 173,000 1.25 177 160** 1" 1 1/2"* 1 1/2" 66" 26" 6" 13 1/2" 22" 438 N/A 72E 67 199,000 1.50 212 160** 1" 1 1/2"* 1 1/2" 58" 28" 8" 16" N/A 503 N/A 73E 67 242,000 1.75 258 180 1" 1 1/2"* 1 1/2" 58" 28" 8" 16" N/A 503 N/A 120E 113 155,000 1.10 163 180 1" 2"* 2" 67" 31 1/2" 6" 19" 22" 709 N/A 190E 113 190,000 1.35 199 180 1" 2"* 2" 67" 3