What is the minimum diameter of a fire hose outlet for an interior wet standpipe?

The minimum diameter of a fire hose outlet for an interior wet standpipe is 38 mm. This specification is critical for ensuring that the outlet can deliver sufficient water flow to effectively combat fires. In fire protection systems, the size of the outlet directly impacts the pressure and flow rate that can be achieved. A diameter of 38 mm is chosen as it balances the need for effective water delivery with the capabilities of modern firefighting hoses, which are designed to accommodate and work efficiently with this size, ensuring optimum performance during an emergency situation.

Using a smaller outlet diameter could limit the water flow, hampering firefighting efforts. Conversely, a larger outlet may not be practical within the design constraints of typical architectural settings and could lead to difficulties in manipulation and connection with hoses. Therefore, the selection of a 38 mm diameter is based on a combination of hydraulic requirements, operational efficiency, and practical application in fire response scenarios.