Low-pressure system

175 psi (1 225 kPa) or less

Intermediate-pressure system

175 to 500 psi (1 225 kPa to 3 500 kPa)

High-pressure systems

500 psi (3 500 kPa) or greater

Compressed-air, nitrogen, or high-pressure water pumps create higher pressures

System is composed of small-diameter, pressure-rated copper, or stainless-steel tubing

Small-diameter spray nozzles are spaced evenly on the tubing

Spray nozzles may be of the open or closed sprinkler variety

A product-of-combustion detection system activates the system

Should also have a means of manual operation

All of the spray nozzles in a particular room or zone are open

When the detection devices activate, the water discharges from the spray nozzles

• Lists requirements for inspecting, maintaining, and service testing water-mist systems

NFPA® 25

• Must be hydrostatically tested on a regular basis
• Empty cylinders must be tested before recharging if it has been more than five years
• Those that have not been discharged should be emptied and tested every twelve years

Cylinders

• Verify that the required number of components are present

Replacement components

• Try to verify that the owner/occupant is servicing the system on a regular basis

Servicing

Lubricating control valve stems

Adjusting packing glands on valves and pumps

Bleeding moisture and condensation from air compressors and air lines

Cleaning strainers

Replacing corroded or painted nozzles

Replacing damaged or missing pipe hangers

Replacing damaged valve seats or gaskets

Commonly employed to protect Class B fire hazards but may also be used for Class A hazards

May also be used to suppress vapors

Designed to a deliver a foam-water solution at the required design concentration over the discharge density and design area of the system

These systems can be wet-pipe, dry-pipe, preaction, or deluge systems

NFPA® 16 details the design and construction requirements of foam-water automatic sprinkler systems

Design professional establishes the required duration for foam application; must be for at least fifteen minutes

Inspector verifies the minimum required volume of foam concentrate and the correct type of foam is being used

The proportioner may be an in-line valve or pump designed to inject and mix the foam with the water to create the foam-water solution at the correct concentration

NFPA® 25 requires an annual test of the proportioner

In certain designs, the ceiling sprinklers are used as the detection feature when the foam-water sprinklers are pre-primed with foam solution

In other cases, a fire alarm and detection system is required to activate the foam-water system

Designed to provide a means for rapidly deploying fire hose and operating fire streams on all levels of multistory structures and at remote points in large-area structures

Intended to be used by firefighters, trained occupants, or both

A permanent water supply that is augmented through an FDC may supply the system

It may be a stand-alone system that requires the fire department to charge the system with water through the FDC

May also be part of or separate from an automatic sprinkler, water-spray, water-mist, or foam-water system

Some building codes require operational standpipes during construction

As construction progresses, the standpipe is extended to subsequent floors

The system may or may not have an attached water supply

Must have appropriate FDCs, hose discharge connections, other necessary appliances

Verify the connection threads on all hose connections and the fire department connections

Systems need to be flow and hydrostatic tested every five years

At a minimum, the Inspector I should request documentation of the last test to verify system readiness

Hose stations (defines classification of system)

Water supplies

Waterflow control valves (similar to those used in automatic sprinkler systems)

Risers (piping systems used to transfer water from the supply to the discharge)

Pressure-regulating devices

Fire department connections (FDCs)

• Primarily for use by firefighters trained in handling large handlines
• Must be capable of supplying effective fire streams during the more advanced stages of fire within a structure
• Have 2½-inch (65 mm) hose connections or hose stations attached to the standpipe riser

Class I: firefighters

• Primarily designed for trained building occupants or fire department personnel
• These systems are equipped with a 1½-inch (38 mm) hose, nozzle, and hose rack
• There is some disagreement over the value of Class II standpipe and hose systems
• Fire department personnel cannot depend on Class II standpipe hose for fire control operations
• The installation of Class II standpipes is declining in favor of Class I or Class III installations

Class II: trained building occupants

• Combine the features of Class I and Class II systems
• Have hose connections for both fire department personnel and the trained building occupants
• The design of the system must allow both Class I and Class II services to be used simultaneously

Class III: combination

• Contains water in the system at all times
• Attached to a water supply capable of supplying the system demand at all times
• When the hose valve is opened, water is immediately available

Automatic-wet

• Contains air or nitrogen under pressure and is permanently attached to a water supply
• Water enters the system when a hose valve is opened

Automatic-dry

• Standpipe with empty pipe that is connected to a permanent water supply
• Uses a device to admit water into the system piping upon activation

Semiautomatic-dry

• Contains unpressurized air in pipes
• No permanent water supply
• Relies on the FDC to supply system demand

Manual-dry

• Contains water in the system from a domestic supply; relies on the fire department to provide water through the FDC to meet system demand

Manual-wet

Water is constantly available at the hose station

Cannot be used in cold environments; dry system, which have higher costs and maintenance, may be necessary

Are standpipes accessible?

Do valves work?

Are the caps in place?

Are doors closed and latched?

Amount of water required depends on the occupancy, height of the building, and the total number of standpipes

Requirements may be reduced by installed automatic sprinkler systems

Some occupancies require secondary water supplies; usually from automatic fire pumps

Be aware of multiple water supplies and verify their operational readiness

The current NFPA® 14 minimum requirement for residual pressure is 100 psi (700 kPa) at the fire hose outlet

Consult the code used in the local jurisdiction for minimum requirements

Ask for inspection and maintenance records

Confirm that the water supply has not been changed and that all valves are accessible

• Most commonly located within rated stair enclosures

Location

• Can be located no more than 6 feet (1.8 m) from floor level
• Must be plainly visible and not obstructed
• Any caps must be easy to remove

Hose connections

• May be required to have a 2½-inch (65 mm) outlet on the roof

Buildings equipped with Class I or III systems

Where the discharge pressure at a hose outlet exceeds 175 psi (1 225 kPa), NFPA® 14 requires a pressure-regulating device to limit the pressure to 100 psi (700 kPa)

Use prevents pressures that make fire hose difficult or dangerous to handle

Enhances system reliability because it extends individual zones to greater heights

May improve system economy because its use may eliminate some pumps

Pressure-regulating devices make the system design more complex

• Consist of a simple restricting orifice inserted into the waterway
• The amount of residual pressure drop through the orifice plate depends on the orifice diameter; available flow and pressure within the system
• Each standpipe discharge connection is fitted with a restricting orifice
• This device is not a preferred type

Pressure-restricting devices

• Preferred for managing excessive pressure
• Considered to be the most reliable method of pressure control
• Use a pitot tube and gauge to read the pressure
• Some of the devices are field adjustable, and others are preset at the factory

Pressure-control devices

• Preferred for managing excessive pressure
• Uses a spring mechanism that compensates for variations in pressure
• Mechanisms balance the available pressure within the system with the pressure required for hoseline use
• Inspectors need to know that the second pipe is for testing of the PRVs

Pressure-reducing devices

Verify that the required testing has been completed

Verify required pressure-reducing valves are installed and tested as specified

Standpipe systems that are equipped with pressure-regulating devices are designed so that they can be routinely tested

Systems must have dedicated drainage pipes with connections on each floor; means for determining water flow

Must be specified and/or adjusted to meet the pressure and flow requirements of the individual installation

A pressure-regulating device that is not properly installed or adjusted may result in seriously reduced available flow and impaired suppression capabilities

Each standpipe system requires one or more FDCs through which a fire department engine can supply water

Large buildings having two or more zones require an FDC for each zone

Standard requirements specify that there shall be no shutoff valve between the FDC and the standpipe riser

Hose connections to the FDC must adhere to the standards of the locally adopted code; have standard cap plugs or approved breakaway covers

Some jurisdictions require large-diameter hose (LDH) connections to supply standpipes

Hose coupling threads should conform to those used by the local fire department

The FDC may also be protected with a locking intake cap that must be removed with a special key

Local authority may regulate the use of these locking caps

A raised-letter sign on a plate or fitting reading STANDPIPE designates the FDC

If the FDC does not service the entire building, the sign must indicate which floors it does service

Found in many commercial, institutional, and industrial facilities

Main function is to increase the pressure of the water that flows through it

Usually needed to supply a sprinkler or standpipe system

High-rise buildings or areas with low static pressure on the public or private water supply may require the installation of fire pumps

Horizontal split-case

Vertical �split-case

Vertical inline

Vertical turbine

End suction

Referred to as a horizontal shaft pump

Drive shaft is on a horizontal plane

Pump on one end of the shaft and the driver on the other

Used to boost the pressure from an incoming, pressurized water source

Not a self-priming pump

Cannot be used to supply water from a static supply source

Not rated at a particular pressure

Impeller shaft runs vertically

Almost always driven by an electric motor that sits on top of the pump

Main advantage of this pump is its compactness

Single-stage pump designed to fit into the intake/discharge line with the driver located above the inline impeller

Advantages include easy installation as a replacement pump; compact; easy maintenance

Has a capacity up to 1,500 gpm (6 000 L/min) and operating pressures up to 165 psi (1 150 kPa)

Commonly used as well pumps in nonfire-protection applications

Impellers are actually located within the water supply source

Water is drawn into the impeller and then discharged up through the impeller casing

Most of these pumps are multistage pumps

As the water exits one impeller, it enters the next

Volume capabilities are consistent with horizontal and vertical split-case pumps

Pumps have center line suction and discharge

Advantages include ease of installation, simplified piping arrangement, and reduced pipe strain

The pumps are self-venting; eliminates the need for an automatic air-release valve

Known as pressure-maintenance pumps, jockey pumps, or make-up pumps

Located in parallel with the primary fire pump

Designed to maintain system pressure and prevent the larger main pump from starting repeatedly for a short period of time

Design may be any one of the pump types mentioned previously

• Electric motor
• Diesel engine
• Steam turbine

Fire pumps are commonly powered by one of three types of drivers

Other types of engine drivers such as gasoline, natural gas, and liquefied petroleum have been used in the past but are not currently recognized in NFPA® codes

Simple, reliable, and easily maintained

Not designed specifically for fire pumps

Motors must meet National Electrical Manufacturers Association (NEMA) requirements

Must have adequate horsepower (hp)

Electric motors powerful enough to power fire pumps may require a larger electrical service to the building

More complex and requires batteries to start

Also requires an on-site fuel supply

Generally more expensive and requires more maintenance than an electric motor

Required to be tested weekly by running it for at least thirty minutes

Use for fire pumps is tested and listed by testing laboratories

Testing agencies have several requirements

Must have a closed-circuit-type cooling system; and a fuel supply to provide at least 1 gallon (4 L) per hp

Must also have an adequate flow of air through the room where it is located

Not as common as the electric or diesel drivers

When an uninterruptible supply of steam is available in sufficient quantities and at sufficient pressure, they are feasible options; if not, it is more economical to use electric- or diesel-driven equipment

Controllers make stationary fire pumps start automatically and stops them automatically

Additional requirements for testing and maintenance are a consideration when pumps are connected to an alternate power supply such as an engine-driven generator

Pressure-sensing switch inside the electric motor detects the drop resulting from the flow of water

The switch then energizes a circuit that starts the fire pump motor

When the water stops flowing in the system, the pressure switch detects the resulting increase in pressure and turns off the pump

Pressure switches are adjustable

Must be properly adjusted for the individual fire suppression system

Controllers also contain a provision for starting and stopping the pump manually

Contains other operating features including a circuit breaker, a power-available indicating lamp, and a running period timer

The function of the running timer is to keep the fire pump motor running for a minimum period of time once the motor has started

Closes the circuit for the starting motor on the diesel engine

• Low engine oil pressure
• High engine coolant temperature
• Failure to start
• Engine overspeed shutdown
• Battery failure

Monitors and contains alarms for several conditions