What Is a Standpipe System?

A standpipe system is an extension of the fire hydrant system that involves a series of pipes that connect a water supply to hose connections. At its core, it is a way of delivering water from one part of a structure to another.

Standpipes are strategically placed pre-piped water delivery systems that can be activated by building occupants or the fire department to help combat fire in an area. Many new buildings include both fire sprinkler systems and standpipe systems, but it is not uncommon for some older buildings to only have standpipe systems.

Types of Standpipe Systems

Standpipe systems can be either simple or intricate, and installed either horizontally or, most commonly, vertically. There are four different types of standpipe systems used in fire protection – wet system standpipes, automatic dry standpipes, semi-automatic dry standpipes, and manual dry standpipes. Here is how each differs:

  • Wet System Standpipe: In a wet system, the standpipe is connected directly to a water source, so water is always in the pipes with the pressure in the system constantly maintained. When the valve is opened, the pressure forces the water out of the hose.
  • Automatic Dry Standpipe: In an automatic dry standpipe system pressurized air is stored inside the standpipe. When the hose valve is opened, water enters the pipes and pushes the air out, thus allowing the water to douse the fire.
  • Semi-Automatic Dry Standpipe: In this type of standpipe system, air is stored inside the pipes but it can be either pressurized or not. Water only enters the system after an actuation device, like a manual pull station or an electrical switch, is activated.
  • Manual Dry Standpipe: A manual dry standpipe consists of empty pipes, there is no air or water in them. Water only enters the pipes after a fire apparatus is connected to supply the system with water.

Depending on a structure’s fire protection needs, a combination of the above standpipe types may also be installed.

Classes of Standpipe Systems

There are three classes of standpipe systems – Class I, Class II, and Class III.

  • Class I: A Class I standpipe system is designed to be used by firefighting personnel only and is most commonly found in a stairwell, in a cabinet in the hallway, or standing alone by an I-beam in an open area. It features a 2½-inch hose connection with no hose attached. The fire department carries their hose packs to the floor level and then connect their hoses to the standpipe system. The connections featured on Class I standpipes must match the hose thread utilized by the fire department.
  • Class II: A Class II standpipe system can be used either by trained personnel, building occupants, or by the fire department. This type of standpipe features a 1½-inch hose connection, and it typically has 100-feet of hose attached and stored in a cabinet. Class II standpipes are not designed to be used to fight the fire, but rather to help occupants safely escape the area using the hose to protect the means of escape and provide a safe passage out.
  • Class III: A Class III standpipe system features both a 1½-inch hose station for trained personnel to use and a 2½-inch hose connection that can be used by the fire department to supply a larger volume of water.

Understanding NFPA 25 Compliance

All standpipe systems are required to follow NFPA 25 compliance guidelines. This standard requires the standpipe’s control valves to be inspected weekly or monthly depending on certain variables. It also requires a quarterly inspection of the pressure regulating devices, piping, and hose connections.

Once a year, the system’s cabinet, hose, and hose storage device are required to be inspected and the alarm device, hose nozzle, and hose storage device tested.
The hose needs to be tested every 3 to 5 years and the pressure control valves and pressure reducing valves tested every 5 years. The standpipe system also needs to undergo a hydrostatic test, a flow test, and a main drain test every 5 years.

Stay Compliant – Schedule Your Standpipe System Inspection Today

Metro Fire Inspections is a licensed and insured full-service fire sprinkler systems company serving New York City, and Westchester, Nassau, and Suffolk counties. We provide consultation and system design services, installations, inspections, as well as service and maintenance that meets or exceeds all National Fire Protection Association (NFPA) codes and standards.

If you need to schedule an inspection of your standpipe system, don’t hesitate to contact us. Call us today at 631-994-0081 or send us a message and one of our team will respond to your inquiry as soon as possible.