Final answer:
Only one refrigerant is recommended to be transported in the same recovery cylinder to prevent cross-contamination and to maintain the integrity of the refrigeration system.
Step-by-step explanation:
When dealing with the transportation of refrigerants in a recovery cylinder, it is recommended to transport only one refrigerant type per cylinder. This practice helps to prevent cross-contamination between different refrigerants, which can cause operational issues and compromise the performance of HVAC systems. Refrigerants have specific properties, and mixing them can alter boiling points, pressures, and other critical attributes necessary for the proper function of refrigeration systems. Hence, for safety, performance, and regulatory compliance, only a single refrigerant should be transported in each recovery cylinder.