What is prohibited when installing water heater relief valve discharge lines?

When installing water heater relief valve discharge lines, the prohibition of using J-hooks for support is based on safety and reliability considerations. J-hooks can allow for movement and vibrations, which may lead to the discharge line becoming dislodged over time. Relief valve discharge lines must be secured properly to ensure they perform their intended function of safely directing any discharge water away from the heater and structure in case of an overpressure scenario.

Using sturdy and approved mounting methods that prevent sagging, movement, or misalignment is essential for maintaining the integrity of the system. Proper support helps ensure that the discharge line remains functional during and after an event where the relief valve activates, helping to prevent water damage or safety hazards.

The other options present different situations regarding the installation. For example, using flexible tubing might be convenient but poses risks of failure under high pressure or temperature conditions. Connecting to storm drains is also discouraged because it can introduce contaminants into the stormwater system and create backflow issues.