He blend is a refrigerant consisting of a blend of isobutane (R-600a) and propane (R-290) developed to replace dichlorodifiuoromethane (R-12) and It i primarily for use in small commercial refrigeration and air-conditioning systems that have traditionally used R12. It operates at similar pressures and possessessimilar volumetricrefrigerating effect to R12 and R134. It.can be used ina R12 or RI 344A compressor or a specific He blend compressor. It can be used with R-12or R-1343 heat exchangersand expansion devices. It is compatible with most common refrigeration materials and lubricants.