What is a horizontal standpipe?

Author: Ray Hermiston  |  Last update: Saturday, June 21, 2025

A standpipe is a system of pipe that delivers a water supply for hose connections and automatic sprinklers in combined systems. Courtesy of MeyerFire. Standpipe systems are typically installed vertically from floor to floor but are considered horizontal when two or more hose connections are installed on a single level.

What are the three types of standpipes?

Standpipes have three major classifications:
  • Class I standpipes serve a 2.5-inch fire hose connection for fire department use. ...
  • Class II standpipes serve a 1.5-inch fire hose connection and are typically found in cabinets. ...
  • Class III standpipes have both connections of Class I and II.

What is the purpose of a standpipe?

The standpipe extends into the building to supply fire fighting water to the interior of the structure via hose outlets, often located between each pair of floors in stairwells in high rise buildings. Dry standpipes are not filled with water until needed in fire fighting.

Does a standpipe need to be vertical?

A standpipe is a rigid type of piping, which serves as a connection to the water supply. It is usually installed in a vertical position and it essentially works as a fire hydrant.

What is the difference between a sprinkler system and a standpipe?

Sprinklers and standpipes are two crucial fire protection systems that safeguard lives and property. A fire sprinkler system discharges water from sprinkler heads to prevent the growth and spread of fire. A standpipe system provides water through hose connections for use by the fire department or trained personnel.

Horizontal Standpipe under 200’

Is it necessary to have a standpipe?

A Class I system is typically required in buildings that have more than three stories above or below grade because of the time and difficulty involved in laying hose from fire apparatus directly to remote floors. For these reasons, Class I standpipes are the required system in high-rise buildings.

Can you drink water from a standpipe?

Public standpipes provide a safe treated water supply for households who need water for drinking and other internal use – such as cleaning and washing. To get large volumes of water from standpipes, see Water carters.

Does a standpipe need a vent?

Unvented pipes are at a high risk of overflowing and releasing harmful gases. For laundry standpipes, the vent should be at least 1 ½” in diameter and located within 5 feet of the trap.

Is a standpipe a riser?

This requires just the standpipe (aka vertical risers) and the horizontal feeds to hose connections (as indicated by the capitalized phrase “supplied by”) to be protected. It's interesting to note that this section did not use the new term branch line.

Is a fire department connection a standpipe?

FDC stands for Fire Department Connection. It is part of a fire sprinkler system or standpipe system. Though easily overlooked by most, the FDC's role in ensuring the effectiveness and success of a fire sprinkler system to suppress a fire is pivotal.

Can a standpipe get clogged?

Common Causes of Standpipe Overflow for Washing Machines

Over time, your washing machine's drain hose can accumulate lint, hair, and other debris, leading to a clogged pipe. When the water cannot flow freely through the hose, it can back up into the standpipe, causing an overflow.

What is the pressure required for a standpipe?

100 psi minimum hose outlet pressure with a maximum of 175 psi for buildings post 1993 edition of NFPA 14 Standard for the Installation of Standpipe and Hose Systems. 65 psi minimum hose outlet pressure with a maximum of 100 psi for buildings prior to 1993 edition of NFPA 14.

How long should a standpipe be?

Standpipes shall extend not less than 18 inches (457 mm) and not greater than 42 inches (1067 mm) above the trap weir. ❖ A standpipe is typically used for capturing the waste flow from a pumped discharge plumbing appliance such as a dishwasher or a clothes washer.

What is the minimum size for a standpipe?

Standpipes shall be at least 4 in. (100 mm) in size. Standpipes that are part of a combined system in a building that is partially sprinklered shall be at least 6 in. (150 mm) in size.

Which is the most reliable fire suppression system?

The most reliable form of fire suppression system for commercial, industrial, institutional, or residential occupancies is the automatic sprinkler system. These systems are highly effective in controlling and extinguishing fires by automatically releasing water in response to heat.

How does a standpipe work?

A standpipe is an open-ended, metal pipe that can be screwed into a basement floor drain to permit the flow of water back up as high as necessary, thereby delaying or preventing a basement flood.

What is a vertical standpipe?

: a high vertical pipe or reservoir that is used to secure a uniform pressure in a water-supply system.

What is the depth of standpipe installation?

1) The standard sized pipe for a standpipe assembly is 25mm, with the service pipe being buried at a depth of between 750mm (minimum) and 1350mm (maximum) and laid to the property boundary. 2) The pipe material needs to be either MDPE in normal ground conditions or barrier pipe in contaminated ground conditions.

What is the difference between a pipe and a riser?

In the world of plumbing and gas engineering, the term 'riser' is of significant importance. A riser, in the simplest of terms, is a vertical pipe that carries water or gas from one level of a building to another.

Does a standpipe need a trap?

The standpipe for the clothes washer must be trapped. The standpipe height should be at least 18 inches (457 mm) and no more than 42 inches above the trap weir.

Does a plumbing vent have to go straight up?

A plumbing vent does not necessarily have to go straight up. While it is common for vents to run vertically and extend through the roof, there are alternative venting methods available, including: Horizontal vents: These vents run parallel to the building's floor and connect to a vertical vent or vent stack.

What is the pipe called that the washer drains into?

A standpipe can be used to connect the washer's drain hose to the home's waste stack. The waste stack (also called a drain-waste-vent [DWV] system) is the pipe that runs throughout the home collecting wastewater from toilets, sinks, and appliances like the washing machine.

Is fire hydrant water OK to drink?

Fire hydrants are connected to the drinking water distribution system which means that the water that comes out of the hydrants to be used to fight fires is the same high quality treated water that comes out of your faucet at home. This system needs to be cleaned and tested peri- odically.

What pressure do you supply a standpipe?

The minimum pressure while flowing the required standpipe flow (500 GPM from the hydraulically most remote standpipe and 250 GPM from each additional standpipe, up to a maximum of 1000 GPM for a fully sprinklered building) shall be 100 psi at any valve outlet while flowing 250 GPM through each valve.

Is a standpipe a fire hydrant?

A standpipe is a type of rigid water piping which is built into multi-story buildings in a vertical position to which fire hoses can be connected, allowing manual application of water to the fire. Within the context of a building or bridge, a standpipe serves the same purpose as a fire hydrant.

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