A refrigeration system has a relief valve discharging R-123. Where must the discharge piping terminate, according to CSA B52, if the charge exceeds the threshold requiring specific discharge provisions?

Question: A refrigeration system has a relief valve discharging R-123. Where must the discharge piping terminate, according to CSA B52, if the charge exceeds the threshold requiring specific discharge provisions?

Answer options:

• Directly into the atmosphere at ground level.
• Into the building's main sewer system. ✅ To the outdoors at an approved location at least 4.5 m above grade and 6 m from occupied spaces.
• Into a sealed containment vessel within the machinery room.

Correct answer: To the outdoors at an approved location at least 4.5 m above grade and 6 m from occupied spaces.

Explanation: For many refrigerants, particularly Class B, and A2/A3/B2/B3 above certain charge limits, CSA B52 Section 7.4.8.4 mandates that relief discharge piping extends to the outdoors at a safe location, typically at least 4.5 m above grade and 6 m horizontally from any ventilation intake, window, or door to an occupied space, ensuring dispersal.