Final answer:
Recovery cylinders must be certified by the U.S. Department of Transportation (DOT) and often by the American Society of Mechanical Engineers (ASME). They must also be clearly marked with the intended refrigerant type and periodically re-certified to adhere to safety standards and legal requirements.
Step-by-step explanation:
Certification for Recovery Cylinders
Recovery cylinders used for the recovery of refrigerants must have certification to ensure they meet certain safety and construction standards. The U.S. Department of Transportation (DOT) issues specifications for recovery cylinders to ensure they can safely handle the pressures associated with refrigerants. Moreover, recovery cylinders should also be certified by the American Society of Mechanical Engineers (ASME), indicating that they meet additional safety and quality standards. It is essential that they are periodically tested and re-certified to maintain these standards over time.
Furthermore, technicians must use recovery cylinders that are clearly marked with the type of refrigerant it is intended for and also have the appropriate certification for that specific refrigerant type. This is critical to preventing cross-contamination of different refrigerant types. It is also a legal requirement to use only certified recovery cylinders when handling refrigerants in many jurisdictions, following environmental regulations such as those outlined in the Clean Air Act, to prevent harmful substances from being released into the atmosphere.