R-13B1 has properties that allow it work well in low temperature refrigeration systems with application temperatures from -40°F down to -60°F. R-13B1 was used in applications colder than R-22 while maintaining reasonable operating pressures, good capacity, and lower discharge temperatures in standard refrigeration equipment designs. In most cases, R-13B1 systems can be retrofitted to R-403B with adjustments in charge size, capillary tube length, and will result in lower suction pressures. The evaporator will operate in a vacuum when the low side temperature is below -55°F. The original lubricants can be used with R-403B, along with any additives the manufacturer may recommend.
The high stage evaporator provides the correct condensation temperature for the low stage so that compressors in both stages can run at "normal" pressures.
An EPA certification card is required to purchase CFC and HCFC refrigerants.