#92 - Standpipe Systems (Part 3): More Standpipe System Components and How to Maintain Them

The design and upkeep needs of standpipe systems are outlined in NFPA 14: Standard for the Installation of Standpipe and Hose Systems and NFPA 25: Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, as well as the International Fire Code (IFC) and the International Building Code (IBC).

In the previous two installments of our series, we first introduced standpipe and then the major system components including pipes, fire pumps, water flow alarms, drains, gauges, and fire department connections. This article will look at additional, vital portions of a standpipe: the hoses, hose connections and stations, and various system valves. This guide explains the purpose of these items and serves as a quick reference for the maintenance and inspection expected of life safety contractors and building owners.

If you're looking to buy components for your standpipe system, QRFS offers a range of gauges, hose valves and accessories, pin rack items, fire hose reels, butterfly valves, check valves, and large cabinets. If you're searching for a test pump to conduct a hydrostatic test, or a flow or flush test on a manual system, feel free to contact us to discuss your test pump needs.

As the name makes obvious, hose connections and valves are the various points within a standpipe system where hoses are connected to the piping in order to fight fires. It is essential that there are enough connections, appropriately spaced, to ensure firefighters have complete coverage of a building when they bring in standard hose lengths. To achieve this, NFPA 14 specifies how many connections are required based on their distance from one another, as well as how they should be placed based on access height requirements and potential obstructions.

From the 2016 Edition of NFPA 14:

Otherwise, the number and size of hose connections depend on the class of system they serve:

Inspections and maintenance required for hose connections:

There are two sets of inspections for hose connections and hose valves listed in NFPA 25, to be conducted annually and quarterly, respectively:

From the 2017 Edition of NFPA 25:

An important note on hose connections: There is a standardized thread that is intended to make it easy for manufacturers to create hose connections that work with most fire department equipment, while also making it simple for building owners to purchase the right components. But not all fire departments use these standard threads – over 100 fire departments use non-standard threads as of 2016. Thus, you must make sure that the couplings on your hose connections are specifically suited for your local fire department’s equipment. (NFPA 14: 11.3.1)

Pin Rack Unit in Wall (Image Source)

Obviously, all Class II and some Class III standpipe systems have pre-attached hoses on site. In a Class II system, this 1.5” hose must be lined, and it can either be a collapsible hose that is stored on a rack or a non-collapsible hose placed on a reel. Hose stations can be stored within cabinets that must be large enough so that there is at least 2” of space between any part of the cabinet and the hose valve. These cabinets must be clearly marked with signage, use tempered glass, and, if a break-glass cover is used, the device used to break the glass must be tethered to the cabinet with a tether that isn’t long enough to break any other nearby glass.

Inspections and maintenance required for hoses and hose stations:

Hoses, hose nozzles, hose storage devices, and cabinets all require annual inspections which take on added importance in a Class II system, which needs hose stations to work as the primary method of fighting a fire. Because on-site hose stations are often infrequently inspected and poorly maintained, these systems (Class II) or components of systems (any on-site, 1.5” hose stations in Class III) are considered less reliable than equipment in other systems. This unreliability, coupled with the fact that authorities have become concerned about non-trained personnel trying to fight a fire, have resulted in Class II systems falling out of favor for new standpipe installations. In addition, fewer Class III systems now have onsite hose stations that any occupant can access and use. If your building has hose stations – especially if it is a Class II system that relies on them – make sure to stay on top of these four annual inspections to make sure they work:

From the 2017 Edition of NFPA 25:

In addition to hose valves, various standpipe systems commonly have control valves, preaction and deluge valves (in semiautomatic dry standpipe systems), pressure-reducing valves (automatic and semiautomatic systems), and check valves.

Control valves control the flow of water to different portions of a standpipe system. They are required in three areas: at the connections to water supplies, at areas where portions of the standpipe need to be isolated, and at the connections to sprinkler systems. In each case, the control valve serves the purpose of cutting off the water to the system (or a portion of the system), so that repairs can be made. Their different locations allow certain portions of a system to be taken out of service while other areas remain operational in the event of an emergency. There are two types of control valve:

Inspection requirements for control valves can be weekly, monthly, and quarterly based on whether they are locked, continuously supervised by personnel, or have electrical supervisory devices in place. These three measures reduce the risk of a control valve being accidentally closed or tampered with, which could render the system or a portion of the system inoperable during a fire. Most AHJs require control valves to be secured or electrically monitored.

From the 2017 Edition of NFPA 25:

Pressure-restricting valves are used to reduce the pressure coming out of hose connections on the lower floors of a tall building. Because greater pressure must be applied to fight gravity to meet demand on high floors, the greater pressure on lower floors may need to be limited to make water flow manageable. These valves come in two varieties:

Inspection requirements for pressure-restricting valves:

Pressure reducing valves on hose stations have annual inspection requirements, whereas inspections of pressure-restricting valves used at hose connections are quarterly.

From the 2017 Edition of NFPA 25:

Preaction and deluge valves are exclusively used in semiautomatic dry standpipe systems. These valves are “tripped” in the event of an emergency, allowing water to flood the usually dry pipes in the rest of the system. The valves are activated by an electrical signal sent from a pull station or button, and they must also have a separate mechanical or hydraulic means of flooding the system as a back-up.

Inspection requirements for preaction and deluge valves:

From the 2017 Edition of NFPA 25:

In addition, “internal inspection of valves that can be reset without removal of a faceplate” should be conducted every 5 years, as well as inspection of “strainers, filters, restricting orifices, and diaphragm chambers unless tests indicate a greater frequency is necessary.” (13.4.4.1.4.1, 13.4.4.1.5)

There are also two types of fire pump relief valves that regulate pressure – circulation relief valves and main pressure relief valves – which are only installed on automatic and semiautomatic standpipe systems. These valves are designed to stop engine overspeed (preventing engine damage) as well as to prevent overpressure in these standpipe systems. These valves must be inspected during any fire pump flow test (see Table 8.1.1.2 in our previous installment of this series).

A check valve is any valve that makes sure that water flows in only one direction. In standpipe systems, check valves are required at the fire department connection (FDC) to avoid spillage when a hose is disconnected, as well as at the connections to any water supply. In a sprinklered building, the latter variety prevents the highly-pressurized water in the standpipes from entering the lower-pressure sprinkler system. In addition, a specific check valve called a backflow preventer is needed to keep any stagnant water in a sprinkler or standpipe system from flooding back into (and contaminating) the city water supply.

Inspection and maintenance requirements for check valves:

From the 2017 Edition of NFPA 25:

Dry pipe valves are only present in automatic dry standpipe systems. They serve as the junction between the water supply and the highly-pressurized air in the pipes of these system, which holds the dry pipe valve closed until the air pressure drops. A loss of air pressure trips the valve and floods the system with water.

Inspection requirements for dry pipe valves:

From the 2017 Edition of NFPA 25:

Similarly, only automatic dry systems require a specific relief valve to be installed at “the air fill connection to prevent the system from putting too much air in the standpipe system.” (Isman, p. 120)

To be continued: The Complete Guide to Standpipe Systems

This concludes part three of our review of standpipe systems, rounding out the major system components and their upkeep requirements. In the next installment of this series, we discuss the regular NFPA testing requirements that ensure that a standpipe system works during a fire.

If you're looking to buy components for your standpipe system, QRFS offers a range of gauges, hose valves and accessories, pin rack items, fire hose reels, butterfly valves, check valves, and large cabinets. If you're searching for a test pump to conduct a hydrostatic test, or a flow or flush test on a manual system, feel free to contact us to discuss your test pump needs.

If you have any questions about standpipes or need help finding an item, add a comment below, give us a call at 888.361.6662, or fill out our contact form and we’d be happy to assist.