A plumbing apprentice is installing a new hot water recirculation line using PEX tubing. What is the maximum continuous operating temperature rating typically allowed for PEX-b tubing in potable water applications, as per manufacturer specifications and Canadian standards?

Question: A plumbing apprentice is installing a new hot water recirculation line using PEX tubing. What is the maximum continuous operating temperature rating typically allowed for PEX-b tubing in potable water applications, as per manufacturer specifications and Canadian standards?

Answer options:

• 60°C
• 70°C
• 82°C ✅ 95°C

Correct answer: 95°C

Explanation: PEX-b tubing is typically rated for a maximum continuous operating temperature of 95°C (200°F) at a specific pressure for potable water applications according to CSA B137.5. Lower temperatures like 60°C are generally too low for hot water distribution, while 70°C and 82°C are below the typical maximum continuous rating.