Standpipe friction loss typically includes a vertical standpipe riser at what psi per floor?

Standpipe friction loss typically includes a vertical standpipe riser at what psi per floor?

• A. 5 psi per floor
• B. 2 psi per floor
• C. 10 psi per floor
• D. 0 psi per floor

Answer: (A)

As a standpipe water has to be pushed up through the vertical riser, pressure is lost due to friction in the pipes as it rises. A practical rule of thumb used in many fire service calculations is about 5 psi of friction loss per floor for the vertical standpipe. This amount accounts for the friction in the riser and fittings and helps estimate the extra pressure needed at the pump so the nozzle on the upper floor still has usable pressure. The other options either understate, overstate, or ignore vertical friction, which would lead to incorrect pump pressures. So, 5 psi per floor is the standard figure used to account for standpipe friction losses as you rise floor by floor.

As a standpipe water has to be pushed up through the vertical riser, pressure is lost due to friction in the pipes as it rises. A practical rule of thumb used in many fire service calculations is about 5 psi of friction loss per floor for the vertical standpipe. This amount accounts for the friction in the riser and fittings and helps estimate the extra pressure needed at the pump so the nozzle on the upper floor still has usable pressure. The other options either understate, overstate, or ignore vertical friction, which would lead to incorrect pump pressures. So, 5 psi per floor is the standard figure used to account for standpipe friction losses as you rise floor by floor.