High-rise standpipe pressure is specified as what?

• A. 1000 kPa for 5 stories plus 35 kPa per floor more
• B. 800 kPa for 4 stories plus 20 kPa per floor
• C. 1200 kPa for 6 stories plus 40 kPa per floor
• D. 900 kPa for 3 stories plus 25 kPa per floor

Answer: (A)

For high-rise standpipes, fire ground pressure is planned to stay adequate at every level by combining a baseline pressure for the lower portion of the building with an increment for each additional floor. The baseline of 1000 kPa is chosen to provide sufficient pressure on the lower floors, and then 35 kPa is added for each floor above those first five to offset the hydrostatic and friction losses as water travels up the standpipe. This approach yields consistent pressure at higher outlets without leaving upper floors under-pressurized or lower floors over-pressurized. That’s why the specification of 1000 kPa for five stories plus 35 kPa per floor more is the best match. The other options use base pressures and per-floor increments that don’t align with how standpipes are typically sized to ensure adequate pressure on all floors.