Ch13 Set 07: Fire Nozzle Types and Operations

What terms does the outline use for straight-tip and spray nozzles?

Smooth-bore nozzles and fog nozzles, respectively.

Where can smooth-bore or fog nozzles be used?

Handlines and master-stream devices, including apparatus-mounted, portable, and elevated monitors.

What are the three principal functions of a nozzle or broken-stream device?

Control water flow, create reach, and shape the stream.

Why are broken-stream delivery devices used?

To apply water to confined spaces that normal attack lines cannot reach.

How is a smooth-bore nozzle shaped internally?

It gradually narrows to a short cylindrical section, approximately 1 to 1½ times its inside diameter, that forms a round stream.

What are the advantages and limitations of smooth-bore nozzles?

Low pressure, less clogging, and suitability for compressed-air foam; limited pattern choice and greater potential for hose kinking at lower pressure.

What determines smooth-bore stream velocity and flow?

Nozzle pressure determines velocity; pressure and discharge-opening size determine flow.

What smooth-bore operating pressures does the outline give?

Usually 50 psi for handlines and 80 psi for master-stream appliances.

How do single and stacked smooth-bore tips differ?

A single-size tip provides one opening; stacked tips permit different openings and flows.

What patterns can a fog nozzle produce?

Straight stream, narrow-angle fog, and wide-angle fog.

What useful capabilities do fog nozzles offer?

Adjustable patterns, wide-fog crew protection, varied applications and designs, and application of certain foams.

What are the four common fog-nozzle types in the outline?

Basic, constant-gallonage, constant-pressure or automatic, and constant/select-gallonage.

How does a basic fog nozzle discharge water?

At a rate determined by its designated nozzle pressure and setting, with an adjustable pattern.

How does a constant-gallonage fog nozzle operate?

At its designated nozzle pressure, flow remains constant as the pattern changes from straight stream to wide fog.

How does a constant-pressure automatic fog nozzle operate?

It adjusts to maintain reasonably constant nozzle pressure through a specified flow range; minimum pressure is needed for a good pattern.

How does a constant/select-gallonage fog nozzle operate?

It allows manual selection of a predetermined flow by adjusting the orifice, including while flowing.

How is flow selected on a manually adjustable fog nozzle?

Rotate the selector ring, usually behind the tip, to a marked gpm setting; flow remains at that setting with adequate pressure.

When may a manual fog-nozzle flow setting be changed?

Before opening the nozzle or while water is flowing.

What manual fog-nozzle adjustment ranges does the outline list?

Depending on size, 10-250 gpm for handlines and 350-2,500 gpm for master streams.

What does a fog nozzle's flush setting do?

Rinses debris out of the nozzle.

Why should fog-nozzle flow be changed in small increments?

Large abrupt changes can alter nozzle reaction and throw firefighters off balance.

How can an operator change flow through an automatic nozzle?

Open or close its shutoff valve within the nozzle's operating range while the automatic mechanism maintains pressure.

What low-, mid-, and high-flow automatic handline ranges does the outline list?

Low: 10-125 gpm; mid: 70-200 gpm; high: 70-350 gpm.

What range and supply arrangements are typical for automatic master-stream fog nozzles in the outline?

350-1,250 gpm, supplied by LDH, multiple lines, or direct pump piping.

Who must coordinate nozzle flow changes?

The nozzle operator, company officer, and pump operator.

What fog-nozzle operating pressures does the outline list?

Most operate at 100 psi; models designed for 75, 50, or 45 psi are also available.

How do lower-pressure fog nozzles differ from 100-psi designs?

Less reaction, larger droplets, lower fog-pattern density, and lower stream velocity.

Where are broken-stream nozzles useful?

Basements, chimneys, attics, and other concealed or confined spaces.

What are examples of broken-stream devices?

Piercing nozzles, Bresnan distributors, and Rockwood cellar pipes.

What materials can a piercing nozzle penetrate?

Stucco, block, wood, and lightweight steel to reach concealed fire.

What are the parts of a piercing nozzle?

A piercing tip, shaft, hose connection, and striking plate; a control valve can be fitted between the hose and connection.

What tools can drive a piercing nozzle into position?

A mallet, sledgehammer, or flathead axe.

How does a cellar nozzle distribute water?

Its rotating head discharges in a circular pattern after being lowered through an overhead opening into a cellar, attic, cockloft, or other confined space.

What cellar-nozzle examples does the outline identify?

Bresnan distributor and Rockwood cellar pipe.

When should nozzles be inspected?

After every use and at least annually.

Who should perform nozzle maintenance?

Routine care follows manufacturer instructions; technical maintenance is performed by qualified technicians.

What gasket and body checks belong in a nozzle inspection?

Check swivel-gasket wear or damage, replace worn or missing gaskets, and inspect the body, coupling, and tip for damage.

What internal and operating checks belong in a nozzle inspection?

Check for internal damage or debris, free movement, a secure pistol grip, and all parts present and in good condition.

How should nozzles be cleaned and stored?

Clean after use with soap, water, and a soft brush; lubricate as directed; store with the bale closed and never drop or drag them.

What if flushing does not clear nozzle debris?

Shut off the supply, remove the nozzle, and physically remove the obstruction.

What do nozzle control valves allow the operator to do?

Start, stop, increase, or reduce flow while controlling the nozzle; slow operation helps manage reaction and prevent water hammer.

What are the three main nozzle control-valve types?

Ball, slide, and rotary control.

How does a nozzle ball valve operate?

A waterway passes through a sealed, supported ball that rotates up to 90 degrees; pull the bale back to open and push forward to close.

What are the open and closed waterway positions of a nozzle ball valve?

Aligned with the nozzle axis when open; perpendicular when closed.

Why is a ball-valve nozzle normally fully opened for best performance?

It provides maximum flow; partial opening can create turbulence and degrade a smooth-bore solid stream.

How does a nozzle slide valve work?

A movable cylinder seats against a shaped cone to stop flow; pulling the handle back slides it open.

What advantage does a slide valve offer?

Flow and reaction control without the turbulence caused by a partly open ball valve.

Where are rotary nozzle valves found, and how do they work?

On rotary-control fog nozzles, often occupant-use standpipe hoses; a screw-guided outer barrel moves around an inner barrel to control discharge pattern.