Pierce HUSKY 12 GPM Manual

© 2017 Pierce Manufacturing Inc. Part No. PM-F-OM131-0517
Operation & Maintenance Manual
HUSKY 12 GPM
FOAM SYSTEM

© 2017 Pierce Manufacturing Inc. All Rights Reserved. Husky 12 Foam System /i
TABLE OF CONTENTS
FOREWORD
1PURPOSE OF MANUAL ..................................................................................................................................... v
2SCOPE ............................................................................................................................................................ v
3CUSTOMER ASSISTANCE INFORMATION ............................................................................................................ v
SECTION 1. SAFETY
1-1 INTRODUCTION ............................................................................................................................................. 1-1
1-1.1 TO THE OWNER—OPERATION AND MAINTENANCE OF THIS APPARATUS ............................................ 1-1
1-1.2 DESCRIPTION OF “DANGER,” “WARNING,” AND “CAUTION” ......................................................... 1-1
1-2 LIST OF ABBREVIATIONS ............................................................................................................................... 1-2
SECTION 2. GENERAL
2-1 HUSKY 12 SPECIFICATIONS .......................................................................................................................... 2-1
2-1.1 FOAM PROPORTIONER .................................................................................................................... 2-1
2-1.2 SYSTEM CAPACITY ......................................................................................................................... 2-1
2-1.3 DISCHARGES .................................................................................................................................. 2-1
2-1.4 SYSTEM ELECTRICAL LOAD ............................................................................................................. 2-1
2-1.5 MAINTENANCE MESSAGE ................................................................................................................. 2-1
2-1.6 FLUSH SYSTEM ............................................................................................................................... 2-2
2-1.7 FOAM CONCENTRATE COMPATIBILITY .............................................................................................. 2-2
2-2 DESCRIPTION OF MAJOR COMPONENTS ........................................................................................................ 2-2
2-2.1 HYDRAULIC DRIVE SYSTEM ............................................................................................................. 2-2
2-2.1a HYDRAULIC GEAR PUMP ..................................................................................................... 2-3
2-2.1b HYDRAULIC OIL FILTER ....................................................................................................... 2-3
2-2.1c HYDRAULIC OIL RESERVOIR ................................................................................................ 2-4
2-2.1d HYDRAULIC OIL COOLER ..................................................................................................... 2-4
2-2.1e HYDRAULIC MANIFOLD BLOCK ............................................................................................. 2-5
2-2.2 FOAM SUPPLY SYSTEM .................................................................................................................. 2-5
2-2.2a FOAM CONCENTRATE TANK ................................................................................................ 2-5
2-2.2b FOAM SUPPLY VALVE ......................................................................................................... 2-6
2-2.2c FOAM CONCENTRATE PUMP ................................................................................................ 2-6
2-2.2d FOAM SELECTOR VALVE ..................................................................................................... 2-7
2-2.2e PANEL MOUNTED STRAINER / EXTERNAL PICK-UP CONNECTION .......................................... 2-8
2-2.2f PICK-UP HOSE ................................................................................................................... 2-9
2-2.2g FOAM CHECK VALVE ........................................................................................................... 2-9
2-2.3 WATER SUPPLY SYSTEM ................................................................................................................ 2-9
2-2.3a MANIFOLD AND MASTER DRAINS ....................................................................................... 2-10
2-2.3b IN-LINE WATER CHECK VALVE ........................................................................................... 2-10
2-2.3c WATER FLOWMETER ......................................................................................................... 2-11
2-2.4 CONTROL HEAD & DISPLAY ........................................................................................................... 2-12

TABLE OF CONTENTS
ii /Husky 12 Foam System © 2017 Pierce Manufacturing Inc. All Rights Reserved.
SECTION 3. OPERATION
3-1 FOAM SYSTEM OPERATION ........................................................................................................................... 3-1
3-1.1 CLASS A FOAM - USING ON-BOARD FOAM TANK .............................................................................. 3-1
3-1.2 CLASS A FOAM - DRAFTING ............................................................................................................. 3-2
3-1.3 CLASS B FOAM - USING ON-BOARD FOAM TANK .............................................................................. 3-2
3-1.4 CLASS B FOAM - DRAFTING ............................................................................................................. 3-3
3-1.5 CHOOSING A FOAM SOURCE ............................................................................................................ 3-4
3-2 FLUSHING SYSTEM ....................................................................................................................................... 3-5
3-2.1 GENERAL FLUSHING INFORMATION ................................................................................................... 3-5
3-2.2 MANUAL FLUSH MODE ..................................................................................................................... 3-6
3-3 PRIMING SYSTEM .......................................................................................................................................... 3-7
3-4 FILLING FOAM TANK ..................................................................................................................................... 3-8
3-4.1 FILL DOME METHOD ........................................................................................................................ 3-8
3-4.2 PICK-UP HOSE METHOD .................................................................................................................. 3-9
3-5 MANUAL MODE (MANUAL WATER FLOW).................................................................................................... 3-10
3-6 DRAINING THE FOAM TANK ......................................................................................................................... 3-11
SECTION 4. MAINTENANCE
4-1 MAINTENANCE INTRODUCTION ....................................................................................................................... 4-1
4-2 TESTING AFTER SYSTEM MAINTENANCE ........................................................................................................ 4-1
4-3 CHECK CURRENT SOFTWARE REVISION ........................................................................................................ 4-2
4-4 DIAGNOSTICS ............................................................................................................................................... 4-3
4-4.1 DIAGNOSTIC INPUTS ........................................................................................................................ 4-3
4-4.2 DIAGNOSTIC OUTPUTS ..................................................................................................................... 4-4
4-5 SET-UP, CALIBRATION, AND MAINTENANCE MODE ACTIVATION ...................................................................... 4-5
4-6 SET UP MODE .............................................................................................................................................. 4-6
4-6.1 PARAMETERS .................................................................................................................................. 4-6
4-6.1a SET AUTOMATIC FLUSH TIME .............................................................................................. 4-7
4-6.1b AUTO START ....................................................................................................................... 4-7
4-6.2 TANK DEFAULTS .............................................................................................................................. 4-8
4-6.2a TANK FILL ENABLE/DISABLE ................................................................................................ 4-9
4-6.2b SELECT SINGLE OR DUAL FOAM TANK SYSTEM .................................................................... 4-9
4-6.3 SET STARTUP OR DEFAULT FOAM SOURCE .................................................................................... 4-10
4-6.4 SET BACK LIGHT ........................................................................................................................... 4-11
4-6.5 SET CONCENTRATE DEFAULT PERCENTAGES ................................................................................. 4-12
4-7 CALIBRATION MODE ................................................................................................................................... 4-13
4-7.1 CALIBRATE FLOWMETER MODE ...................................................................................................... 4-13
4-7.2 CALIBRATE FOAM PUMP (LVDT) TRANSDUCER .............................................................................. 4-14
4-7.3 CALIBRATE CLASS A FOAM MODE ................................................................................................. 4-15
4-7.4 CALIBRATE CLASS B FOAM MODE ................................................................................................. 4-16
4-7.5 RESTORE DEFAULTS ..................................................................................................................... 4-17
4-7.6 PROGRAMMING ............................................................................................................................. 4-18

© 2017 Pierce Manufacturing Inc. All Rights Reserved. Husky 12 Foam System /iii
TABLE OF CONTENTS
4-8 MAINTENANCE MODE ................................................................................................................................. 4-19
4-8.1 RESET MAINTENANCE REMINDERS / TIMERS .................................................................................. 4-19
4-9 TROUBLESHOOTING ................................................................................................................................... 4-20
4-10 PERIODIC OPERATION ................................................................................................................................ 4-32
4-11 GENERAL MAINTENANCE PROCEDURES ...................................................................................................... 4-32
4-12 PREVENTIVE MAINTENANCE CHECKS AND SERVICE .................................................................................... 4-33
4-12.1 INTRODUCTION ............................................................................................................................. 4-33
4-12.2 EXPLANATION OF COLUMNS .......................................................................................................... 4-33
4-13 AFTER EVERY USE INSPECTION ................................................................................................................. 4-34
4-14 WEEKLY INSPECTION ................................................................................................................................. 4-34
4-15 QUARTERLY INSPECTION ............................................................................................................................ 4-35
4-16 ANNUAL INSPECTION ................................................................................................................................. 4-35
4-17 RECOMMENDED HYDRAULIC OIL FOR HUSKY 12 PROPORTIONING SYSTEM ................................................. 4-35
4-17.1 CHARACTERISTICS ........................................................................................................................ 4-35
4-17.2 RECOMMENDATIONS ..................................................................................................................... 4-35
4-17.3 OIL CHANGE INFORMATION ........................................................................................................... 4-36
4-18 SYSTEM DIAGRAMS ................................................................................................................................... 4-37
INDEX

TABLE OF CONTENTS
iv /Husky 12 Foam System © 2017 Pierce Manufacturing Inc. All Rights Reserved.

© 2017 Pierce Manufacturing Inc. All Rights Reserved. Husky 12 Foam System /v
FOREWORD
1. Purpose of Manual
The information in this manual is for the operation and maintenance of Pierce Husky 12 Proportioning System. It is
intended to serve as a guide to assist qualified operators and mechanics in the operation and maintenance of their
vehicle.
Keep this manual with the vehicle at all times.
NOTE: Some of the details of your vehicle’s design and construction may be unique to your department
alone. For this reason, information contained in this manual may be generic at times. Questions on
major inconsistencies between your vehicle’s configuration and the information contained in this
manual should be directed to your Pierce Dealer or Sales Representative.
2. Scope
This supplemental operator’s manual provides operating and maintenance instructions for Husky 12 Proportioning
Systems on vehicles manufactured by Pierce Manufacturing Inc.
This manual provides information under the following headings:
Safety. Contains important safety information, requirements before placing a vehicle in service, and information on
installing custom equipment and accessories.
General. Includes information and instructions on the operation of major systems, controls, and indicators.
Operation. Contains procedures on performing common operations.
Maintenance. Contains scheduled preventive maintenance checks and inspections.
Appendixes. Contains information obtained directly from vendors who supply major components found on this unit.
3. Customer Assistance Information
Your satisfaction with your Pierce apparatus is important to your dealer and Pierce Manufacturing Inc. Normally, any
question or concern you may have with your apparatus can be handled by your selling or servicing dealer. Your
dealer has the facility, trained technicians, special tools, and up-to-date information to promptly address any issue
that may arise. Pierce Manufacturing Inc. has empowered dealers to make decisions and repair vehicles, and they
are eager to resolve your issues to your complete satisfaction. Should you encounter an issue with your Pierce
apparatus that requires service, take the following steps:
Step 1.) Contact your authorized Pierce selling or servicing dealer. They will make the necessary arrangements to
order the necessary parts and make the required repairs.
Step 2.) If they are not able to repair the problem to your satisfaction, discuss your concern with a member of dealer
management. Normally, concerns can be quickly resolved at that level. If the matter has already been reviewed with
the Sales, Service, or Parts Manager, contact the owner of the dealership or the General Manager.
Step 3.) If, after contacting a member of the dealership management, it appears your question or concern cannot be
resolved by the dealership without further help, you may contact Pierce Manufacturing Inc. at 888-Y-PIERCE (888-
974-3723).

FOREWORD
vi /Husky 12 Foam System © 2017 Pierce Manufacturing Inc. All Rights Reserved.

© 2017 Pierce Manufacturing Inc. All Rights Reserved. Husky 12 Foam System /1-1
SECTION 1 SAFETY
1-1. Introduction
1-1.1 To the Owner—Operation and Maintenance of This Apparatus
The information in this manual is for the operation and maintenance of this apparatus. The intent is to instruct
operators in the proper operation of this equipment and to warn of improper procedures and potentially dangerous
situations.
Only personnel who are totally familiar with this manual and have training are qualified to operate this apparatus. It
is the responsibility of the department owning this equipment to permit only qualified personnel to operate this
apparatus.
Qualified drivers of other fire apparatus will require further training for the handling of this unit.
1-1.2 Description of “DANGER,” “WARNING,”and “CAUTION”
THIS SAFETY SYMBOL INDICATES IMPORTANT SAFETY MESSAGES IN THIS MANUAL.
WHEN YOU SEE THIS SYMBOL, CAREFULLY READ THE MESSAGE THAT FOLLOWS THIS
SYMBOL.
BE ALERT TO THE POSSIBILITY OF PERSONAL INJURY OR DEATH.
Warninglabelslocatedonthevehicleand warning statementscontainedin this manual allusethe same terminology
to warn of potential hazards. Each of these potentially harmful conditions is described below:
The “signal words” of DANGER, WARNING, and CAUTION have specific meanings to alert you to the relative level
or probability of the hazard.
Take the safety warnings seriously. If you do not understand them or have questions about them, contact Pierce
Manufacturing Inc.
A hazard that will result in death or serious personal injury.
A hazard which might result in death or serious personal injury.
A hazard which might result in personal injury or damage to property or equipment.

SAFETY
1-2 /Husky 12 Foam System © 2017 Pierce Manufacturing Inc. All Rights Reserved.
1-2. List of Abbreviations
TERM DEFINITION
AFFF Aqueous Film Forming Foam
AR-AFFF Alcohol Resistant Aqueous Film Forming Foam
FFFP Film Forming Fluoro-Protein
GPM Gallons per Minute
LCD Liquid Crystal Display
LPM Liters per Minute
NFPA National Fire Protection Association
PSI Pounds per Square Inch
RPM Revolutions per Minute

© 2017 Pierce Manufacturing Inc. All Rights Reserved. Husky 12 Foam System /2-1
SECTION 2 GENERAL
2-1. Husky 12 Specifications
2-1.1 Foam Proportioner
The foam proportioning system is an on demand, automatic proportioning, single point, direct injection system
suitable for all types of Class A & Class B foam concentrates, including the high viscosity (6000 cps), alcohol
resistant Class B foams. The operation of the system is based on direct measurement of water flow, and remains
consistent within the specified flows and pressures. The system automatically balances and proportions foam
solution at rates from 0.1% to 9.9% regardless of variations in water pressure and flow, up to the maximum rated
capacity of the foam concentrate pump.
The design of the system allows operation from draft, hydrant, or relay operation. This provides a versatile system
to meet the demands at a fire scene.
2-1.2 System Capacity
The system has the ability to deliver the following (minimum) foam solution flow rates at accuracies that meet or
exceed NFPA requirements at a pump rating of 250 PSI.
Table 2-1: Maximum Foam Solution Flow
The Class A foam setting is in .1% increments from .1% to 1%. Typical settings are .3% and .5%. *The maximum
capacity is limited to the plumbing and water pump capacities.
2-1.3 Discharges
The number of discharges capable of dispensing foam varies from truck to truck, depending on customer
specifications. Foam discharges can be identified by red/white tags; water only discharges can be identified by
silver/black tags.
2-1.4 System Electrical Load
The electrical load for the foam proportioning system is less than five (5) amps at 12VDC.
2-1.5 Maintenance Message
Amessage is displayed on thecontrolheadto notify the operator when systemmaintenanceneeds to be performed.
The message displays the interval for cleaning the foam strainer & water strainer, and changing the hydraulic oil.
These messages will appear after 20 hours of foam system operation if not reset during normal maintenance.
Concentration Percentage Capacity
6% 200 GPM
3% 400 GPM
1% 1,200 GPM
.5% 2,400 GPM*
.3% 4,000 GPM*

GENERAL
2-2 /Husky 12 Foam System © 2017 Pierce Manufacturing Inc. All Rights Reserved.
2-1.6 Flush System
A flush mode allows the system to flush all foam concentrate with clear water. The flush circuit control logic ensures
the foam tank supply valve is closed prior to opening the flush valve. The flush valve is electrically controlled and
is operated from the foam system control head.A manual flush drain valve is located under the driver’s side running
board.
2-1.7 Foam Concentrate Compatibility
The Husky 12 Foam Proportioning System is designed to be compatible with most known ClassA and Class B foam
concentrates at the date of printing of this manual.
The Husky 12 can proportion foam concentrates across a wide range of viscosity, from low viscosities such as Class
A or AFFF, through high viscosity AR-AFFF.
Table 2-2: Acceptable Foam Concentrate Viscosity Range
2-2. Description of Major Components
To understand the relationship of the various components and their functions, refer to “System Diagrams” on
page 4-37. The following information is intended to identify the various components and describe their function
within the system. For specific construction, maintenance, and parts information, please refer to applicable service
groups (chapters) in the service manual, drawings included in this manual, and the parts catalog for this unit.
2-2.1 Hydraulic Drive System
The hydraulic drive system that powers the foam pump is automatically activated when the water pump is engaged.
Ahydraulic oil cooler prevents overheating of the hydraulic oil, whichcan be detrimentalto systemcomponents. The
oil/water cooler is designed to allow continuous system operation without allowing hydraulic oil temperature to
exceed the oil specifications.
The system is delivered with ISO 68 hydraulic oil.
Emulsifier type agents may cause damage to seals in Husky foam systems.
In the event you are using an emulsifier type encapsulator agent, do not store foam system wet.
Perform a flush after every use and keep system dry when not in use.
Failure to comply may cause damage to equipment.
Acceptable Foam Concentrate Viscosity Range
Minimum 3 Centistokes
Maximum 6000 Centipoise*
* Brookfield #3 Spindle @ 30 RPM

© 2017 Pierce Manufacturing Inc. All Rights Reserved. Husky 12 Foam System /2-3
GENERAL
2-2.1a Hydraulic Gear Pump
Figure 2-1: Hydraulic Gear Pump
1001
The larger line is inlet from hydraulic tank; the smaller line is pressure line that drives the foam pump. The pump
may be driven directly off Hale pump transmission, the Waterous impeller shaft, or a transmission-driven PTO
(Chelsea) controlled by the pump engaged circuit #1659.
2-2.1b Hydraulic Oil Filter
Figure 2-2: Hydraulic Oil Filter
1002
The Hydraulic Filter is a pressure bypass element-type filter manufactured by Hydac. The filter element is
replaceable. The unit is installed inside the pumphouse and is used to filter the pressurized hydraulic loop. The
replacement part number for the filter element is Pierce P/N 1460998.

GENERAL
2-4 /Husky 12 Foam System © 2017 Pierce Manufacturing Inc. All Rights Reserved.
2-2.1c Hydraulic Oil Reservoir
Figure 2-3: Hydraulic Oil Cooler
1003
TheHydraulic Reservoir(approximatelyfour galloncapacity) provides areservoir for thehydraulic drive system.The
tank is sufficient size to minimize foaming of the hydraulic fluid and is located to facilitate checking level and adding
oil. Refer to “Recommended Hydraulic Oil for Husky 12 Proportioning System” on page 4-35, for recommended
hydraulic oil for the Husky 12 system.
2-2.1d Hydraulic Oil Cooler
Figure 2-4: Hydraulic Oil Cooler
1004
ToHydraulic
Pump
Shut-offValve(in-line
position is OPEN)
HydraulicOil
In/Out Cooling Water In/Out

© 2017 Pierce Manufacturing Inc. All Rights Reserved. Husky 12 Foam System /2-5
GENERAL
The Hydraulic Cooler is an oil-to-water type heat exchanger. It takes water directly from the water pump to cool the
closed loop hydraulic system. The cooling water is then returned to the water pump suction while the cooled
hydraulic oil is returned to the hydraulic tank. The hydraulic cooler allows for continual operation of the Husky 12
hydraulic system.
2-2.1e Hydraulic Manifold Block
Figure 2-5: Hydraulic Manifold Block
1005
The Hydraulic Manifold Block assembly is a manifold block that controls the direction of the hydraulic oil flow in the
system. The manifold block consists of the machined block, a hydraulic compensating valve, an internal hydraulic
shuttle valve, a hydraulic relief valve, hydraulic pressure test port and the hydraulic proportional valve.
2-2.2 Foam Supply System
The Foam Supply System stores, pumps and distributes the foam concentrate to the foam/water discharges by use
of a foam concentrate tank, foam tank shut-off valve, auxiliary foam inlet, in-line foam strainer, foam pump, check
valve and foam injection manifold.
2-2.2a Foam Concentrate Tank
The Foam Concentrate Tank is designed to provide on-board storage of foam concentrate. Design features shall
include: construction compatible with foam concentrates, foam tank drain valve, expansion dome with locking fill
hatch and pressure/vacuum vent. The expansion dome allows for changes in foam concentrate volume due to
variations in temperature. Foam concentrate level shall be maintained at the one-third full mark in the expansion
dome at a minimum to reduce the air to foam concentrate interface. The pressure vacuum vent automatically
balances internal foam tank pressure under both suction and filling operations. It is recommended that a cleanable
foam concentrate level unit be installed in the storage tank. The control head will display a warning message when
the foam tank being used is below one quarter tank.
Forward Plug
Hydraulic
Relief Valve
Reverse Plug
Not shown: P1 pressure
test port (on side of
hydraulic block)

GENERAL
2-6 /Husky 12 Foam System © 2017 Pierce Manufacturing Inc. All Rights Reserved.
2-2.2b Foam Supply Valve
Figure 2-6: Foam Supply Valve
1006/1007
Anelectric/air valve is usedforthe Foam Supply Valve.Thefoamsupply valve shall becontrolledat the foam system
control head for ease of operation. The supply valve is located to eliminate air pockets in the foam tank supply hose.
This foam supply valve opens automatically when the system is turned ON.
2-2.2c Foam Concentrate Pump
Figure 2-7: Foam Concentrate Pump
1008
The Foam Concentrate Pump assembly is a brass/steel constructed, double-acting cylinder pump. The hydraulic
end of the pump is painted steel and controls the speed and direction of both cylinders. The hydraulic piston is
connected to the foam piston by a single, straight shaft. The foam end of the pump is brass construction and
contains 4 cartridge type check valves to prevent foam from flowing the wrong direction in the pump.

© 2017 Pierce Manufacturing Inc. All Rights Reserved. Husky 12 Foam System /2-7
GENERAL
The foam pump also has a pressure relief valve that recirculates the foam from the discharge side to the inlet side
in the case of an obstruction or overpressure situation. The foam pump speed and operation are monitored by a
foam pump transducer located in the hydraulic end of the pump assembly.
The foam concentrate pump is self-priming and has the capability to draw foam concentrate from external supplies
such as drums or pails. The foam concentrate pump has a maximum capacity of 12 GPM with all types of foam
concentrates with a viscosity at or below 6000 cps including protein, fluoroprotein, AFFF, FFFP, or AR-AFFF.
2-2.2d Foam Selector Valve
Figure 2-8: Foam Selector Valve
1009
The Foam Selector Valve is a 2-way, quarter-turn ball valve that directs the foam for foam injection (normal
operation) or tank filling.A “CHECK SELECTOR VALVE” message is displayed by the control head in the event that
the valve is not in the correct position for the operation selected.
From Foam Pump
Tank Fill Hose*
Injection Hose
*A foam selector valve
withthe tank fill option is
shown. On units without
thetank fill option, the fill
hose will be routed
directly to tank.

GENERAL
2-8 /Husky 12 Foam System © 2017 Pierce Manufacturing Inc. All Rights Reserved.
2-2.2e Panel Mounted Strainer / External Pick-Up Connection
Figure 2-9: Panel Mounted Strainer / External Pick-Up Connection
1010
A bronze body strainer / connector unit is mounted on the pump panel. The external foam pick-up consists of one
(1) 1 in. male connection with chrome-plated cap, integrated to a 2 in. strainer clean-out cap. A check valve is
installed in the pick-up portion of the clean-out cap. A basket style stainless steel screen is installed in the body of
the strainer / connector unit.
The strainer is used to prevent any debris from entering the foam system and possibly interfering with the internal
foam pump check valves.
Removal of the 2 in. clean-out cap is all that is required to gain access to and remove the stainless steel basket
screen. The strainer / connector is located ahead of the foam concentrate pump inlet port, to insure that all agent
reaching the foam pump has been strained.
The external foam pick-up permits the use of a foam agent that is not stored on the vehicle. The external foam pick-
up also allows continued operation after the on-board foam tank is empty. The external foam pick-up can also be
used with training foam or colored water for training purposes.
This connection also functions as the Class A tank fill (when equipped with tank fill option) and as the foam tank
drain.

© 2017 Pierce Manufacturing Inc. All Rights Reserved. Husky 12 Foam System /2-9
GENERAL
2-2.2f Pick-Up Hose
Figure 2-10: Pick-up Hose
1012
A 1 in. flexible hose, with an end for insertion into foam containers, is provided. The hose has a 1 in. female swivel
NST thread swivel connector. (The hose is part of loose equipment.)
2-2.2g Foam Check Valve
Figure 2-11: Foam Check Valve
1013
The Foam Check Valve located in the foam supply line prevents water from flowing backwards through the foam
system and contaminating the foam supply.
2-2.3 Water Supply System
The water supply system supplies water to the foam injection manifold for foam to be added and distributed to the
foam/water discharges. This system consists of an in-line water check valve, water flowmeter and flowmeter
installation tee. The size of the check valve and the flowmeter installation tee are dependent on the number of foam/
water discharges in the system.

GENERAL
2-10 /Husky 12 Foam System © 2017 Pierce Manufacturing Inc. All Rights Reserved.
2-2.3a Manifold and Master Drains
Figure 2-12: Manifold & Master Drains
1066/1067
The manifold drains are used to bleed off pressure/water anytime the water pump has been pressurized (after the
water pump is shut off). If a dry water pump condition is desired, leave manifold drains open until the fire scene is
reached.
The master pump drain will empty both the discharge and inlet manifolds of water when opened. The water pump
drain should be pulled (opened) daily.
2-2.3b In-line Water Check Valve
Figure 2-13: In-line Water Check Valve
1014
The In-line Water Check Valve prevents foam from entering the water pump and the remainder of the water system.
It is installed in the water piping, before the foam injection manifold and the water flowmeter.