Question 28

The minimum size supply pipe for a hose bibb is 1/2 inch.

To ensure adequate water flow and pressure for a hose bibb, a 1/2 inch supply pipe is necessary given the daily static service pressure of 55 psi and a maximum developed length of 80 feet.

A) 3/8 inch

A 3/8 inch supply pipe is insufficient for maintaining the required flow and pressure at the hose bibb. This size may lead to inadequate water delivery, especially over the developed length of 80 feet, resulting in potential pressure losses that can affect performance.

B) 1/2 inch

The 1/2 inch supply pipe is the appropriate size to provide the necessary flow rate for the hose bibb under the given conditions. It balances the need for sufficient water pressure and volume, making it the correct choice for optimal functionality.

C) 5/8 inch

While a 5/8 inch supply pipe may allow for increased water flow, it is not the minimum size required for the installation. Therefore, it does not directly address the question of minimum sizing, which specifically seeks the smallest adequate option.

D) 3/4 inch

A 3/4 inch supply pipe exceeds the minimum requirement for the hose bibb. Although it would provide ample flow and pressure, it is unnecessarily large for the context of the question, which asks for the minimum size.

Conclusion

The 1/2 inch supply pipe is the minimum necessary size to ensure sufficient water flow and pressure for the hose bibb at the specified service conditions. Options A, C, and D do not meet the criteria for minimum sizing, either by being too small or unnecessarily large, while option B provides the optimal solution.