What is the minimum design pressure for a standpipe system at the hydraulically most remote 1½-inch hose valve outlet?

The minimum design pressure for a standpipe system at the hydraulically most remote 1½-inch hose valve outlet is established at 65 psi. This requirement is based on the ability of the system to deliver an adequate supply of water under pressure to combat fires effectively, especially in the most challenging scenarios where the hose is extended to its furthest reach.

Standpipe systems are critical components of a building's fire protection strategy and are designed to ensure that hose connections provide the necessary pressure and flow to be effective. The 65 psi pressure standard is intended to overcome both the friction losses in the hose and fittings, as well as any elevation gain that may occur when utilizing the standpipe to reach higher floors.

Establishing a minimum of 65 psi ensures that firefighters have enough pressure to achieve the required flow rates for effective firefighting. This pressure also serves to compensate for variations that may occur due to the layout of the piping system, length of hose deployment, and specific building characteristics. Thus, having a predefined design pressure helps ensure that the standpipe system is reliable and effective in emergency situations.