Question 143Refrigeration & AC - Assistant Engineer

The correct answer is C) both liquid and vapor. The push-pull technique is used to recover refrigerant from a refrigeration system in both the liquid and vapor states. This method involves pushing the liquid refrigerant from the system using high-pressure nitrogen or air, while simultaneously pulling the vapor refrigerant using a recovery unit. This allows for the efficient and complete removal of the refrigerant from the system, regardless of its physical state. The other options are incorrect because the push-pull technique is applicable for recovering both liquid and vapor refrigerant, not just one state, and it can be used with low-pressure systems as well.