Refrigeration system isolation valves are specially designed with a backseat, as well as a front seat. For what purpose are these valves designed in this way?

Correct Answer: Option C — permit repacking the valve stem under pressure without shutting down

Refrigeration service valves feature a backseat design that seals the stem packing chamber when fully opened, permitting technicians to safely repack the valve stem under active system pressure without evacuating the charge.