Throughout the US, including in Chicago, home of the historic Chicago water tower, standpipes, or as they are otherwise known as, are rigid water piping units that allow fire hoses to be connected for water based fire suppression. Their original use was for cylindrical water towers such as the historic Chicago tower to maintain water pressure for distribution systems. More recently the term describes dedicated piping systems within buildings used for fire suppression with the same purpose as fire hydrants. First set in Code in 1914 by the Committee on Standpipe and Hose Systems, standpipes were first designed to meet the needs for fire suppression on upper floors of buildings. There are three different classes of automatic, wet or dry standpipes. These and their variants are described in more detail later here.Standpipe classes
- Class I standpipes connect to a 2.5-inch fire hose connection and are for fire department use.
- Class II standpipes connect to a 1.5-inch fire hose connection and are usually housed in cabinets.
- Class III standpipes have Class I and II connections
As water is drawn from a standpipe valve, the valve acts as a ‘hoseline pump’ and the controller a ‘pump operator’ who adjusts pressure for proper water flow.
The regulatory backdrop to standpipes in Chicago.
There can be points of contention between the various parties involved in fire protection system design, specification and installation. It's worth describing some of the applicable code requirements here to give an overview of the areas of concern. Note this article is for informational purposes only. Current editions of code should always be consulted prior to design, specification or installation.
National Fire Protection Association (NFPA) 14, the "Standard for the Installation of Standpipe and Hose Systems", outlines the requirements for the installation of standpipes and hose systems throughout the US. It serves to ensure that systems function as intended to provide adequate and reliable water supplies in a fire emergency. On the other hand NFPA 25 is the "Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems." Compliance with this code assists in maximising system integrity to avoid failure and provide fast, effective response in a fire emergency.
NFPA 14 informs the regulations in the International Fire Code (IFC) and the related International Building Code (IBC). IBC influences most adopted building codes for US states and cities for 'required installations.' The commonest and most comprehensive qualification used to determine if a standpipe system is necessary is a building’s height.
From the IBC, Class III standpipe systems should be installed where the floor level of the highest story is over 30ft above the lowest level of fire department vehicle access in a building, or where the lowest story floor level is over 3 ft below the highest level of fire department vehicle access.
The municipal code of Chicago also sets out specific location requirements for standpipes in the city according to building height:
Buildings over 80ft high: Standard internal standpipe systems should be provided in all buildings over 80ft high although there are some exceptions, including the following:
- Institutional Units. In institutional units, standpipes shall be provided in all buildings more than 4 stories or 55ft in height.
- Stage Blocks. In stage blocks, standpipes shall be provided on each side of the stage, on each tier of dressing rooms, and within 55ft of all property rooms, store rooms or work rooms.
- Storage Structures: standpipes are not required in grain elevators or similar storage structures. In these situations they are ineffective owing to the type of structure and inaccessibility of hose connections.
- Exhibition Areas: standpipes should be provided regardless of building height. Each standpipe location should provide complete coverage of a fire area with 100ft hose lengths and 30ft hose streams.
In the interest of life safety, it should be recognised that the most onerous height standard should apply.
Benefits of all standpipes
The general benefits of using standpipes are as follows:
Time saving: time is saved by having fixed standpipe hose outlets.
Fixed equipment: heavy wet hoses may slide downward if inclined whereas standpipes are fixed.
Safety: standpipe installation keeps areas clear and safe for exiting occupants.
Improved water pressure/friction loss: vertical standpipe installation reduces hose length and improves water pressure and fiction loss.
Redundancy: should the main water distribution system within a building fail or be compromised by a fire or explosion, redundancy, or back up, is provided.
Flood prevention: standpipes can provide flood protection to below ground areas.
Disadvantages of all standpipes
Not fail safe: standpipes are not fail safe systems. There have been many instances where fire operations have been compromised by non-working standpipe systems.
Pipe distance: when obtaining water from a standpipe riser and valve, water often has to flow a long way which can effect its pressure. Pipe can be supplied from a local water utility. This may or may not have a fire pump to augment pressure and require specific valves and a fire department that enables manual pressure augmentation.
Valve flushing: firefighters should take care to flush the standpipe before use to clear corrosive deposits and ensure water is available (or flush air if dry standpipes).
Valve position: lightweight elbows may be required to prevent hoseline kinking at the valve.
Valve control wheel opening: firefighters may have to force open a valve the first time it is used or when making adjustments.
Description: There are two types of automatic standpipe system:
- Automatic systems - set out to provide the needed pressure and water supply when the valve is opened.
- Semi-automatic systems - set out to provide the needed pressure and water supply, after the activation of a control device or fire pump.
Description: There are two types of dry standpipe system:
- Automatic dry systems - designed to have water in the system piping when in use.
- Manual dry system - exclusively for fire department use and require a pumper to supply pressure and water through a connection.
Use: These can only be used only by firefighters not occupants. Fire fighters often bring hoses in with them and attach them to standpipe outlets located along the pipe throughout the structure.
- Automatic wet system - connected to a permanent water supply capable of meeting flow and pressure requirements and permanently filled with water.
- Manual wet system - not connected to a permanent water supply. A fire department connects to a hydrant, supplies the system and a standpipe is then filled with “priming water” to reduce the time taken to channel water to hose station outlets.
Use: Wet standpipes are generally equipped with hoses for building occupants as well as firefighters to use.
Given the variety of standpipe types available and complexity of location aspects for standpipe application, it's important to obtain professional advice. Recourse can be made to a standpipe fire protection expert familiar with fire suppression in Chicago and other code requirements to provide the correct system design, specification and advice on standpipe installation and maintenance.