STANDPIPE SYSTEMS DESIGNS, operations, and flows vary widely. Unlike sprinkler systems, standpipe systems are not automatic fire suppression systems and cannot extinguish a fire without human intervention. A properly operating and maintained building standpipe system is a valuable tool when mounting an interior, offensive fire attack. In fact, in high-rise structures it may be impossible to conduct a safe and effective interior operation on upper floors if the standpipe system is inoperable.
The most common type of standpipe is the automatic wet standpipe system. A properly maintained and operating wet standpipe with an adequate water supply should immediately flow water when the discharge valve is opened at the point of service. In areas subject to freezing, dry standpipes may be used. They are usually filled with pressurized air or nitrogen that is purged before water flows into the system when the discharge valve is opened.
Automatic standpipe systems are more dependable than manual systems for several reasons. Manual systems rely on the fire department to supply water by way of a fire department connection, meaning the fire attack could be delayed. In addition, dry manual systems are more likely to have unknown damage, open valves, and open discharge caps.
High-rise buildings cannot have manual standpipe systems, which are allowed only in low-rise buildings. However, other buildings may have standpipe systems of varying types. For instance, newer big-box mercantile properties will often have a sprinkler system with a hose connection. These “hose drops” typically do not meet the same requirements as standpipe systems. When hose drops are attached to a sprinkler system, they must be accounted for in the hydraulic calculations, up to at least two inside hose connections. This requirement is intended to ensure that a fire line attached to the hose drop does not rob water from the sprinkler system.
When conducting pre-incident planning, it is important to include a study of the building’s standpipe system that indicates whether the standpipe is equipped with any pressure-regulating devices and how those devices operate.
A common type of regulating device, the pressure reducing valve (PRV), controls the pressure at the outlet under flowing, as well as static, conditions. However, PRVs can be problematic during fire department operations, as evidenced by the One Meridian Plaza fire, a blaze in a high-rise office tower in Philadelphia in 1991 that killed three firefighters. At that fire, the PRVs were improperly set to reduce the pressure to a level that was ineffective for a fire attack.
Settings for these valves must take into account the hose diameter and nozzle types carried in firefighters’ standpipe kits. Properly calculating pump pressure and elevation loss is also part of the procedure to deliver the right quantity of water at the right pressure throughout the system. For instance, buildings that are not equipped with PRVs generally have higher pressures on lower floors and lower pressures on higher floors.
Standpipe standard operating procedures address tasks to be performed and equipment to be carried into the building, and these procedures must be constantly reviewed. Successful standpipe operations dictate that training and standard operating procedures accurately reflect the information obtained through pre-fire planning.
Ben Klaene is the former safety/training chief for the Cincinnati Fire Department. Russ Sanders is executive secretary of the Metro Fire Chiefs Association and the former chief of the Louisville Fire Department.