Fire officer handbook of tactics 6.

• Automatic sprinkler systems act as silent sentinels, activating immediately to suppress fires.
• Working sprinkler systems are crucial as they almost eliminate loss of life for civilians and firefighters.
• Sprinkler systems have a high success rate, controlling or extinguishing fires over 96% of the time with often only one or two heads activated.
• Multiple-death fires (more than three fatalities) have never occurred in buildings with fully operational wet-sprinkler systems.
• Human error, especially closed valves, is the main cause of sprinkler system failure to control fires.
• Fire departments sometimes shut off sprinkler systems, leading to catastrophic fires due to the belief that manual firefighting is sufficient.
• It's generally better to let sprinkler systems operate until the fire is extinguished, as removing them can lead to loss of control.
• Connecting to hydrants on the same main as the sprinkler system can drop pressure to sprinkler heads.
• Supplying the siamese connection early with multiple large hose lines discharges water at higher pressure directly onto the fire.
• Aim for each sprinkler head to cover 100 sq ft with a 20 gpm flow when planning to supply FDCs.
• Operate the supply pumper in volume at 150 psi, because most pumpers can discharge their maximum rated capacity at this pressure.
• High-pressure pumping can damage sprinkler systems due to rust, corrosion, impact, freezing, expansion and contraction

Smoke Conditions

• Fires in sprinklered buildings can be smokier because early detection and water application thwart combustion, increasing carbon monoxide levels.
• Water spray cools fire gases, causing them to sink, and creates a draft that pushes smoke down, eliminating the fresh air layer along the floor.
• SCBA use is essential due to increased carbon monoxide, sinking fire gases, and smoke being pushed down.
• Mechanical ventilation is often required to remove cold smoke, especially in below-grade areas.

Problems with Sprinklers

• Sprinklers activating after firefighters arrive can cause burns and reduce visibility due to steam and hot water.
• Partial sprinkler systems might not extinguish fires in rooms without sprinkler heads, requiring immediate location of the shutoff valve.
• Sprinkler heads located inside skylights prevent effective ventilation by driving smoke and heat downwards.
• Ventilation difficulties arise due to cooling and downward pushing of smoke by sprinklers, requiring techniques like fog lines, fans, PPV, or HVAC systems.

Suggested Strategy

• Know the location of sprinkler system shutoffs and siamese connections beforehand, with doors to valve rooms clearly marked.
• Commit supply lines to sprinkler siamese connections early, providing proper volume and pressure.
• Have handlines in place, staffed by SCBA-equipped members.
• Ventilate the area, anticipating difficulties and using proper techniques.
• Only shut down the sprinkler system after the fire is definitely under control, then drain and restore it to service.

Types of Systems

• Automatic Wet System: Most common, with water in piping at all times.
• Automatic Dry System: Used in unheated areas, filled with air under pressure, and more complex than wet systems.

Automatic Wet System

• The system has an alarm valve that prevents water from flowing back out of the sprinkler piping, but opens to allow water to flow to the heads
• The clapper on the check valve covers a small pipe when the check valve is closed
• When the clapper opens to let water flow to a sprinkler head, it also transmits an alarm by allowing water to flow through this small pipe, tripping electric switches or turning the paddle wheel of a water motor alarm bell
• False alarms can occur due to large fluctuations in water supply pressure
• Can be adjusted so that water will flow for a longer period before it sets off the alarm
• Alarms can also be triggered by start-ups and shutdowns of industrial pumps at nearby factories

Automatic Dry Systems

• Pipes are filled with air under pressure and water is held back in a heated area by a dry-pipe valve
• Air must be continuously available to this system from a compressor or bottles and regulators
• The dry-pipe valve works to hold air in the system
• This valve has a larger top than bottom surface
• Most valves have about 30-40 psi on top which will hold back up to 100 psi
• Dry-valve clapper has a lock-open feature to prevent the system from filling with water
• Water columning can occur when water above the clapper is so high that its weight will hold the clapper closed, even after the air has bled out

Deluge systems

• These consist of a piping system connected to a water source that is controlled by an automatic valve
• Open sprinkler heads are attached to the piping throughout the area
• These heads are merely nozzles instead of heat-sensing elements
• The area is protected by a fire detection system connected to the deluge valve
• When the detectors sense fire, they open the deluge valve and water flows into the system and out of all the heads in the area
• Used to protect areas such as aircraft hangars and flammable-liquid loading docks, where an extremely rapid spread of fire is expected
• When the dire has been extinguished, us great care in shutting down any control valves, since the large flow can easily create a dangerous water hammer if the system is closed too quickly

Preaction systems

• It consists of an automatic detection system coupled to an automatic dry-pipe system
• They are often installed over very expensive electronic equipment that could be damaged by a water leak
• The piping is usually filled with compressed air and connected to an automatically operated valve that exhausts the compressed air only if the detection system (heat- or smoke-activated) sense fire
• Systems saves time in getting water on the fire, since it doesn't require that all of the air bleed out through a sprinkler before the dry valve trips
• Differs from a deluge system in that it uses closed sprinklers , so water discharges only over the fire area
• Heat detectors are used not only to activate the system but also to shut it off when the area has cooled

Nonautomatic systems

• Fire codes called for sprinkler systems to be installed in commercial cellars and subcellars of large urban areas
• The comprise was to install a system with no water supply connection other than the fire department siamese, so firefighters wouldn't have to descend into those hellish areas
• The first attempts to provide some type of sprinkler system in these areas involved so-called perforated-pipe systems, which consisted of rows of pipes with small holes (⅛ in to ¼ in) drilled every few inches along the top and sides.
• They functioned much like a modern deluge system, in that water came out of every pore when the system was supplied by a fire hose
• Telephone-switching centers used a custom-designed nonautomatic system using 365° temperature sprinkler heads connected to piping designed to withstand 1,500°F for 15 minutes
• The system remains nonautomatic to protect the delicate electronic switching gear from accidental water leakage

Combination sprinkler and standpipe systems

• These extend sprinkler protection into existing unsprinklered high-rise buildings in the early 1970s
• Sprinkler contractors would tap into the existing standpipe riser, instead of running a whole new riser to supply the sprinklers
• The problem is that new buildings are being built this way, with hydraulically calculated piping that removes all the reserve out of the system

Size-up at Sprinklered Buildings

• Determine whether an auxiliary system is present, indicated by method of alarm receipt or exterior signs like a siamese connection.
• Prefire inspection and preplanning are the best ways to determine the position,location and type of controls of the sprinkler system.
• Determine whether the building's sprinkler system is operating upon arrival, and immediately call for assistance if there is a serious fire.
• Sprinkler alarms often receive minimal response, as commercial buildings require a full response team to attend.
• Building codes often permit trade-offs in materials with higher risks (flame spread/smoke) in sprinklered buildings, posing danger if sprinklers are OOS.
• Alert interior team members before supplying a FDC. A steam/hot water cloud will descend on members.

Fire in Buildings with Sprinklers Not Operating

• Stretch handlines and conduct a manual attack, making efforts to get the sprinklers into action.
• Begin supplying the FDC and monitor the effect.
• If OS&Y valve is closed, pumping water into the FDC will not feed water.
• As soon as possible, send a reconnaissance team to the sprinkler control valve location equipped with a portable radio, looking for closed valves.
• A recon crew should verify the position of control valves, in case closed control valve is a sign of arson.
• Remind the recon crew that part of their job is to verify the actual position of the control valves, since a closed control valve may be an indication of arson.
• If valves are located and opened, this crew should stand by at the valves awaiting orders to close them if they suddenly cause severe operating problems or if large breaks in piping are discovered that render the system inoperable.
• If the building isn’t occupied, look for obvious signs of water flow and proceed based on whether there are signs of a problem or not; if not pressure surge is most likely.
• If there is any sign of smoke/waterflow, force entry.
• Make a lot of noise before entering a building
• Advise the owner (in writing) of any damage incurred while forcing entry
• Check for a malfunctioning gong or alarm and examine the premises to assess for fire/water damage.
• Address issues of limited water supply dependent on fire department support, such as from gravity or pressure tanks.
• At arson fires, water flow can be shut off after heads are activated. Investigate, in case of arson.

Controlling Fire Pumps

• Reset a sprinkler system if tripped to stop a 1,500-gpm automatic fire pump for running without water, thus preventing pump damage.
• Locate the system control and station a two-person team to be able to identify the chief components of the control valves and know how to operate them
• Know that control valves are generally located near the outside signs of the sprinkler system but that isnt always the case
• Valve locations may be at ceiling height as well, and that in recent years the hydraulic design of sprinkler systems has changed
• Modern sprinkler systems are often designed as loops of equal-diameter supply mains surrounding the building, cross-connected to form a grid

Sprinkler System Controls

• OS&Y (outside stem and yoke) valves are common, indicating open/closed position by stem visibility.
• PIV (post indicator valve) and WIV (wall indicator valve) show open/shut status via a sign within the stem.
• Firefighters should recognize and operate the 2-in. main drain valve to speed drainage and reduce water damage.

Restoration of Protection

• Replace fused heads with spare heads, matching temperature & style, marking the location with tape.
• Should be a temporary measure until a contractor arrives and corrects choice
• Direct the owner to have the system examined and heads inspected by a qualified sprinkler contractor.
• Sprinkler heads are marked for temperature and color-coded, unless chrome-plated.
• Sprinkler heads are marked for their intended placement as follows: upright, pendant, or sidewall

Standpipe Systems

• Standpipe systems are passive, requiring fire department pumpers to supply water.
• NFPA 14 outlines five standpipe system types: automatic wet, automatic dry, semiautomatic dry, manual wet, and manual dry.

Manual Standpipe Systems

• Dry: Vertical pipe with valved outlets, filled by the fire department, but vulnerable to corrosion and open valves.
• Fire departments should discourage dry systems
• Wet: Small water supply reduces corrosion and open valve issues, but it is too small to supply more than one adequate firefighting stream.

Automatic Standpipe Systems

• Wet: Preferred type, water under pressure for rapid application, but may be impractical in freezing conditions.
• Semiautomatic Dry: Alternative for freezing areas, with deluge-type valve connected to manual pull boxes.
• Automatic Dry: Similar to dry sprinkler systems, not common due to maintenance and air bleeding issues.

Water Supply

• Water source knowledge (volume and pressure) is crucial; limited tank supplies require prompt pumper support.
• Pressure in gravity tank-fed systems relates to hoseline height below water level.
• In many locales, all that is required is a single FDC with two 2½-in. inlets, regardless of the size of the structure
• High priority must be placed on augmenting the domestic supply to the standpipe
• Have supply lines stretched to pump into the first-floor hose outlets of each riser, in addition to the siamese, whenever a serious fire demands the use of a standpipe system

Standpipe Classes

• Class I: For fire department use, with 2½-in. outlets. Building occupant operation is possible, but not normally expected.
• Class II: For building occupants, with 1½-in. hose with open tip or fog nozzle, 100 gpm flow is not sufficient for department use.
• Class III: Allows heavy streams, includes 2½- and 1½-in. outlets, with possible reducer compromises for occupant use.

Fire Department should avoid using occupant hoses

• Class II hose lacks inspection, is often missing, damaged, or has a closed sprinkler valve, needing 400–500 gpm.
• A 2½−in by 1½-in reducer is placed on the 2½-in outlet valve
• Hose for occupant use [Should] be located outside the stairwell on the fire floor
• Automatic pressure protection for untrained operators prevents excessive outlet pressure.
• This can be an orifice plate or vane-type PRV restrictor.
• Monitor outlet pressure and communicate with officers/pump operators to maintain proper pressure.
• Remove reducer before fire department hose is connected. Use a tool to check for obstructions.

Pressure-Reducing Devices (PRD)

• Combination outlet control and pressure-reducing valves must be bypassed by removing a pin, or metal tap behind valvestem.
• Bypass-required devices existed during One Meridian Plaza; a fire where the ineffective system contributed to firefighter deaths.
• Valve maintenance and flow testing is crucial to prevent failure. Use should be discouraged wherever possible.

Operations

• Size and ventilation difficulties lead to large fires in standpipe-equipped buildings.
• Determining which buildings have standpipes is crucial in prefire planning to equip accordingly
• First actions in a plan is to determine the location of fires and whether standpipes will be needed
• Fires on ground floor hoses should be stretched off, as routine handline is faster, although standpipes are favoured on high floors due to ease.

Attack Crew responsibilities

• Attack crew should advance with the needed equipment to the staircase nearest the fire
• Members of the ladder company or the officer in charge of the hoseline should perform a quick survey
• Select the riser closest to the seat of the fire, with limited required reach,
• The pre-1993 version of the NFPA called for each point on a floor to be within 30 ft of a 100 ft hoseline, whereas present NFPA 14 requires that each point be within 150ft + staircase height (five lengths).
• A provision allows maximum distance limitations to be met by placing the standpipe outlets outside the protection offered by the enclosed stairways in a public hall
• Key Part of standpipe operations is the proper equipment/sufficient personnel must all arrive at the fire zone
• The standpipe kit bag should contain a hose of sufficient length
• You must visit each structure in your area to observe a standpipe system to know how to use it properly to contain a situation
• Before you can connect to any standpipe system, you need to look inside to see its not a drop off point for drug users
• As the plan begins, all must remember that, fires at standpipe-equipped buildings tend to become major events for a number of reasons, the first of which is the sheer size of such a structure. If they aren’t sprinklered, the potential fire area is quite large.