MIL-U-17691D, MILITARY SPECIFICATION: MILITARY SPECIFICATION: UNIT HEATER, AIR-CIRCULATING, STEAM - HOT WATER (23-MAY-1988) [S/S BY S-U-2833]

MIL-U-17691D, MILITARY SPECIFICATION: MILITARY SPECIFICATION: UNIT HEATER, AIR-CIRCULATING, STEAM - HOT WATER (23-MAY-1988) [S/S BY S-U-2833]., This specification covers unit air heaters using steam or hot water as the heating medium