R

321

ND

The pump will not workuntil truck is in driveand road gear switchedto pump gear

TransmissionPump Shifter

The Engine or some powersource provides power through a

transmission to the drive axle

DRIVE

PUMP

DRIVE

PUMP

DRIVE

PUMP

When shifted into pump gear, andtransmission shifted to drive, power

is diverted to power the pump

Every pump needs power to function. “Apparatus” typically use an engine/transmission (Mid-Ship) while “Portable pumps” may have a direct drive from

engine to pump.

REARAXLE= Air Pressure

Road Gear

R

321

ND

TRANSMISSION - NuetralR

321

ND

REARAXLE

Middle

= Air Pressure

TRANSMISSION - Nuetral

VPS

REARAXLE= Air Pressure

PumpR

321

ND

TRANSMISSION - NuetralR

321

ND

REARAXLE= Air Pressure

Impeller Turning

Pump

TRANSMISSION - Drive

What happens when you use the pump shifter and the transmission shifter?

Air pressure moves the VPS Shifter and shift fork forward, aligning the main gear with gears which will turn the impeller gears. The rear drive axle is “disconnected.”

Once the transmission is shifted into drive, power from the Engine/Transmission are now directed to the pump

The rear drive axle is ready to gain power from the Engine/Transmission

Pump shifter is in its middle pause position(Moving the pump shifter from “road” to “pump” should take NO LESS THAN 3-5 seconds)

Note the orange circle in the drawings. This is the switch that once the VPS shift rod moves away, a signal is sent to activate the “OK to pump” green light on the dash or pump panel.

You must provide a source of water to enter the pump. On most initial attack operations, your supply will be the booster tank on the apparatus.

Note – If the valve is not opened or an external source of water does not enter, the spinning impeller will create heat and will eventually cause damage to the pump

#1 2½” #2 2½”

Deck GunR Rear 1¾”L Rear 1¾”BoosterL Rear 1¾”Booster

Li ght

Manual Over ri de

Tank Fill

Pr imer

Dr ains

Valve connected to a handle on the pump panel

Each apparatus will have a “Tank To Pump” valve handle located in a different area. Become familiar with each location.

Tank to pump valve handle

You must know what hoselines have been pulled to eventually open the proper valve in step 4. In some cases you may be the firefighter pulling a hoseline.

Walk all the way around. Make sure the hose is ALL THE WAY out of its bed. If a kink or part of the hose remains in the bed it may become lodged and unusable once the line is pressurized

200' 1¾” CAFS Capable attack line

200' 1¾” CAFS Capable attack line

800' 2½” Supply line Forward Lay

400' 2½” Reverse lay with gated wye attachedOverfill placed nearer to the right sideof truck body toward the front?

Deck gunGEN

Each discharge is labeled. You will have to match

the color or wording with the same valve handle

label at the pump panel

Pull the valve handle which supplies water to the hoselinewhich has been pulled off the truck

Each discharge is labeled. You will have to match

the color or wording with the same valve handle

label at the pump panel

Only applies to a “2-Stage Pump” (Engine 61)The Transfer Valve sets the pump in “Pressure/Series” or “Volume/Parallel”

The purpose of a transfer valve is efficiency of RPMs

Pressure/Series

If impeller 1 gives 75psi

Focus is on wanting pressure

Impeller 2 adds 75psi = 150psi

Volume/Parallel

75psi

75psi

Twice the GPM/Same RPM

Focus is on wanting more waterTransfer Valve Discharge Manifold

Suction SuctionCheck Valve

ImpellersCheck Valve

(Open) (Open)

Volume Operation(Parrallel)

Transfer Valve Discharge Manifold

Suction SuctionCheck Valve

ImpellersCheck Valve

(Closed) (Closed)

Pressure Operation(Series)

How do I know to use Pressure or Volume?

The rule is based on “Half the rated capacity of the pump”

If over ½ the rated capactity of the pump

Transfer valve set in VOLUME

If under ½ the rated capactity of the pump

Transfer valve set in PRESSURE

1250

0

625

Example - E61 is a 1250gpm rated pump - 625gpm is half

Throttle below 50psi if you must switch during operations

You must know the correct pressure for the line/s in use. Increasing the throttle increases the engine speed causing the impeller to turn faster.

The smaller gauges go to individual lines

Suction Discharge“Master Gauges”

Using the Electronic Pressure Governor by pressing the “preset” then adjusting if needed

or pressing the increase button

Using the manual throttle cable on the pump panel

OR

Throttle up till your HIGHEST PSI LINE’S needed PSI is met on your “Master Discharge” gauge. Other lower PSI lines must be “gated down.”

The Relief Valve System is designed to re-route excess pressure and avoid causing damage to hoselines or pump parts.

How it worksThe Pilot Valve (What you see at the pump panel)

And the Relief Valve itself, located inside the pump

Purpose: Adjusts tension on a spring seatedagainst a diaphragm. The more compressedthe spring is, more water pressure is requiredto move the diaphragm back to let water flowto the relief valve.

Purpose: When water pressure is not coming fromthe Pilot Valve, the relief valve remains stationary. When water pressure does come from the PilotValve, it pushes the Relief valve and allows waterpressure from the discharge side of the pump toflow to the intake side of the pump relieving theexcess pressure

Pump Intake

Discharge

Pump Intake

Discharge

Pump Intake

Discharge

Pump Intake

Discharge

Flowing water at 160psi Nozzle closed too quickly, PSI increasesHigher PSI than the setting pushes back Pilot

Valve Spring and travels to Relief Valve

PSI higher than the pilot valve setting “pushes” the relief valve which moves, allowing higher PSI to flow by into the intake side of the pump or to the atmosphere (outside).

The PSI reading will drop as this occurs.

If the higher PSI was caused from closing a nozzle too quickly, the PSI will recover after the relief valve does its job

If the higher PSI was caused from too many RPMs or “over throttling,” you will have to adjust the throttle setting or

change the Pilot valve setting.