Layout requirements and water pressure standards for outdoor fire hydrants in hotels
I am fire protection expert Alexander Li. As a high-occupancy venue, a hotel's rational layout of outdoor fire hydrants and guaranteed water pressure are the key defense line for initial firefighting, directly related to the building's fire safety rating and fire rescue efficiency. In several five-star hotel projects, I have encountered acceptance rectification due to unreasonable outdoor pipe network design, so I have deep experience with this issue. The following is a detailed analysis based on GB50016 Code for Fire Protection Design of Buildings and GB50974 Technical Code for Fire Protection Water Supply and Hydrant Systems.
**I. Layout Requirements for Outdoor Fire Hydrants**
1. **Spacing and Protection Radius**: According to Article 8.1.2 of GB50016, the layout spacing of outdoor fire hydrants shall not exceed 120 m, and the protection radius shall not exceed 150 m. In hotel projects, I often recommend controlling the spacing at 80-100 m, especially covering high-risk areas such as the main entrance, service passages, and boiler rooms. For example, in one hotel project, because the outdoor roads were curved and hydrants were laid out only at 120 m spacing, the protection radius at the terminal area exceeded the limit, and two additional hydrants were required before passing fire acceptance.
2. **Location Selection**: Hydrants should be arranged along roads and close to intersections or fire access lanes. Article 8.1.3 of GB50016 emphasizes that hydrants should be no more than 2 m from the roadside, no less than 5 m from the building exterior wall (to prevent impact from collapse), and shall not obstruct traffic. In hotel design, I often place them at the edge of parking lots or in green belts and ensure fire trucks can stop easily.
3. **Quantity Calculation**: Determined by the number of simultaneous fires and the water demand for one firefighting operation. Taking a typical hotel as an example, the outdoor fire hydrant water demand is usually 20-30 L/s (based on building volume and fire hazard class), each hydrant is counted at 10-15 L/s, and 2-3 hydrants are required. I once handled a case: a resort hotel with a volume exceeding 50,000 m³ required 25 L/s per the code, but the design had only 2 hydrants; this was resolved by adding 1 hydrant and adjusting the pipe network diameter.
**II. Water Pressure Standards**
1. **Minimum Pressure**: Article 7.2.8 of GB50974 stipulates that the outlet pressure of outdoor fire hydrants shall not be lower than 0.1 MPa (about 10 m water column), but in practice, I recommend at least 0.15 MPa to account for hose head loss. In hotel projects, I have encountered municipal network pressure of only 0.08 MPa, resulting in insufficient hydrant discharge; this was later resolved by adding booster pumps and pressurizing the fire water tank to meet the requirements.
2. **Flow Requirements**: Article 3.2.2 of GB50974 has clear flow requirements; for example, a Class I high-rise hotel (building height > 50 m) requires an outdoor flow of 30 L/s. Design should be calculated based on the most unfavorable point to ensure the pressure at the end of the network meets the standard.
3. **System Type**: When water is supplied directly from the municipal network, its pressure and flow must be verified; if a temporary high-pressure system is adopted, the fire pump head should ensure the hydrant pressure at the most unfavorable point. For example, in one hotel project, because the municipal network pressure fluctuated greatly, I added a fire water tank and pressure stabilization equipment in the design, avoiding insufficient pressure during nighttime peak water use.
**III. Practical Engineering Case**
I once participated in the renovation of a boutique hotel located in an old urban area. Its original outdoor fire hydrant was only 1, with pressure of only 0.08 MPa. According to the code, I added 2 hydrants as required by GB50016 (spacing 80 m) and introduced a fire water tank pressurized to 0.15 MPa. During construction, due to complex underground pipelines, I adjusted the hydrant positions (avoiding gas pipelines), and the project finally passed acceptance. This case shows that layout must be combined with site conditions and cannot mechanically copy the code.
**Summary**: The layout of outdoor fire hydrants in hotels should strictly follow the requirements of GB50016, such as spacing ≤ 120 m and distance from buildings ≥ 5 m; water pressure should be at least 0.1 MPa (0.15 MPa or above recommended); and the quantity should be reasonably calculated based on building volume and fire risk. Design should give priority to municipal conditions and add pressurization facilities when necessary.
The above are reference opinions. The actual project situation still needs further comprehensive evaluation and implementation in combination with specific operating conditions, site conditions, and other factors.