When a water tank serves both domestic and fire protection, the domestic connection shall be connected where relative to the level for the fire protection demand?

When a water tank serves both domestic and fire protection, the domestic connection shall be connected where relative to the level for the fire protection demand?

• A. Above
• B. At the same level
• C. Below
• D. Not connected

Answer: (A)

When a single tank serves both domestic and fire protection, the height at which the domestic connection taps into the tank matters for pressure and cross-flow control. Connecting the domestic line higher than the level used for the fire protection demand keeps the two systems effectively separated in terms of elevation. As water is drawn for firefighting and the tank level drops, the fire protection demand draws from the lower portion while the domestic supply still has pressure from water near the top. This arrangement helps prevent siphoning or cross-flow between the systems and maintains domestic pressure during a fire event. If the domestic connection were at the same level or below, firefighting could more readily affect domestic pressure or create backflow opportunities. So, the domestic connection should be placed above the fire protection demand level.

When a single tank serves both domestic and fire protection, the height at which the domestic connection taps into the tank matters for pressure and cross-flow control. Connecting the domestic line higher than the level used for the fire protection demand keeps the two systems effectively separated in terms of elevation. As water is drawn for firefighting and the tank level drops, the fire protection demand draws from the lower portion while the domestic supply still has pressure from water near the top. This arrangement helps prevent siphoning or cross-flow between the systems and maintains domestic pressure during a fire event. If the domestic connection were at the same level or below, firefighting could more readily affect domestic pressure or create backflow opportunities. So, the domestic connection should be placed above the fire protection demand level.