Armstrong FLO-RITE-TEMP 415 Guide

FLO-RITE-TEMP
INSTANTANEOUS WATER HEATER
INSTALLATION AND ADJUSTMENT INSTRUCTIONS
FOR SINGLE AND DOUBLE WALL UNITS
Bulletin No. AY-780-L
This bulletin should be used by experienced personnel as a guide to the installation of the
FLO-RITE-TEMP Instantaneous Water heater. Selection or installation of equipment should always
be accompanied by competent technical assistance. You are encouraged to contact Armstrong
International, Inc. or its local sales representative for additional information.

2
NOTICE
No water heater will work satisfactorily if improperly installed and operated. These instructions contain important
informationfortheinstallationandadjustmentoftheFLO-RITE-TEMPWaterHeaters.Readtheseinstructionscarefully
beforeinstallingthisunit. FAILURETOADHERETOTHESEINSTRUCTIONSCOULDRESULTINSERIOUS
BODILYINJURYORPROPERTYDAMAGE.
STEAM PIPING INSTALLATION OF A SINGLE UNIT
FLO-RITE-TEMP
INSTANTANEOUS WATER HEATER
INSTALLATION AND ADJUSTMENT INSTRUCTIONS
NOTE:unitsmaybepipedinparallelfor largercapacityrequirements. SeeFig.15-1foranexampleofparallelunit
installation.
The unit includes the mixing valve mounted to the heat exchanger, channel iron and U-bolts mounted, thermostatic
air vent installed on the heat exchanger, a water pressure pop off valve integral to the unit control valve and a separate
Armstrong Inverted Bucket Steam Trap.
STEAM SIDE INSTALLATION
(RefertoFig.2-1)
1. Install theFLO-RITE-TEMP withadequateroom toallow for tubebundle removal whencleaning is required.See
Table12-1forspecificdimensions.
2. If 2-15 psig of steam is available a pressure reducing valve is NOT required. If a pressure reducing valve is required,
an Armstrong Inverted Bucket Steam Trap is recommended to drain condensate at the inlet of the pressure reducing
valve.
3. An Armstrong Y-strainer should be installed before the pressure reducing valve to reduce the chance of dirt
fouling.
Fig. 2-1
NOTE: FLO-RITE TEMP is provided with (1) one Armstrong Steam Trap and Thermostatic Air Vent
(shaded). All other items shown not included.
Single and Double Wall
Steam In
2-15 psig Steam
in the Shell
Gate
Valve
Pressure
Gauge
Armstrong
TVS Trap
Armstrong
I.B. Trap
Vacuum
Breaker
Armstrong Thermostatic
Air Vent
Armstrong Pressure
Reducing Valve (if req'd)
GP-2000
Safety Relief
Valve

3
WATER PIPING INSTALLATION
(Follow same plumbing for DW units)
4. If an externally piloted pressure reducing valve is
used, the control pipe should be pitched away from
the PRV and installed at the pressure gauge on the
shell of the heat exchanger.
5. A steam safety relief valve should be used prior to
the heat exchanger if either or both of the following
conditionsexist.(1)Ifthemaximumsteampressure
could exceed the minimum water pressure in the
tubes,or (2)The maximumsteam pressure could
exceed150psig(themaximumsteampressurerating
of the shell).
IMPORTANT-Steamsupplypipesizecomingtothe
heatexchangershouldNOTbesmallerthanthesteam
connectionsuppliedontheheater,otherwisesteamflow
couldberestricted. Ifapressurereducingvalveisused,
installationshouldbeascloseaspossibletotheFlo-Rite-
Temp. DownstreampipingfromthePressureReducing
ValveshouldbeexpandedimmediatelyafterthePRVto
accomodatetheexpandedvolumeofsteam.
6. To vent start-up air, an Armstrong Thermostatic Air
Vent is included and installed on the top connection,
opposite the trap drain connection of the heat
exchanger. This discharge can be piped to drain or
thefloorifpreferred.
7. Install a vacuum breaker in the piping between the
heat exchanger drain connection and the steam trap.
This will prevent improper draining of the heat
exchanger caused by a possible vacuum forming
when the steam is shut off.
8. Install a suitable steam pressure gauge in the 1/4"
coupler located in the top mid section of the heat
exchanger shell. This gauge will help diagnose
pressure problems should they occur. This port may
alsobe usedfor a PRVexternal control pipeif aPRV
isrequired.
1. An 18 inch minimum thermal loop should be piped into the water inlet and outlet of the FLO-RITE-TEMP and
should be located as close to the mixing valve as possible (See Fig. 3-1A). These loops will act as a thermal check
valve or heat trap to prevent the conduction of heat through the water from the unit during inactive times.
2. Isolation valves and hose connections added to both the inlet and outlet water supplies will allow for
Clean-In-Placeequipmenttobeutilized.
3. Use pipe unions on both the water inlet and outlet to allow ease of water heater mixing valve removal for
maintenance and removal of the tube bundle for cleaning (See Fig. 3-1A).
4. For adjusting the unit, an isolation valve and hot water by-pass to drain should be installed close to the unit down
stream from the thermal loops and prior to the recirculation loop (if one is used) (See Fig.
3-1B). This allows for quick and easy setting of the FLO-RITE-TEMP by one person. By isolating the unit from the
hot water system, flow can be controlled to drain through the globe valve while monitoring outlet water temperature
during low and high flow adjustments on the water heaters mixing valve.
Fig. 3-1
D
C
E
B
A
F
A
C
B

4
7. For a recirculated system, a small constant running
pump should be piped in on the return side of the
loop (See Fig.3-1D). This pump should be sized to
moveapproximately10%ofthemaximumratedgpm
ofthe FLO-RITE-TEMPinthe systemwith enough
head to overcome the head encountered in the loop.
NOTE:Athermometershouldbeinstalledinthe
outgoinglooptomonitorsystemtemperature
(Fig.3-1E). Athermometermayalsobeinstalledonthe
loopreturntomonitortemperaturedropthroughtheloop
ortohelptroubleshootthedivertingvalve(Fig.3-1D).The
thermometerreferredtoinpoint#4andFig.3-1Bshould
onlybeusedtosettheFLO-RITE-TEMPandneverusedto
monitorsystemtemperature.
NOTE:Expansiontanksshouldbeusedinon/off
demandapplicationswherethereisashortdurationof
timefromhighflowtonoflowofwater,i.e.,ashutofftime
of 10 seconds or less. (See Fig. 3-1F)
Minimumlinesizestodrainshouldbeasfollows:
model415=3/4",model535=1",model665=
1-1/4",model8120 =2".Line sizessmaller than
thesewillnotallowsufficient flow for makinghigh
flow settings on the mixing valve.
5. A water temperature gauge should be installed
directly after the by-pass drain valve. This
thermometer is only used for inital temperature
adjustments of the Flo-Rite-Temp or troubleshooting
theunit. (SeeFig.3-1B)
6. If a recirculation system is used with a FLO-RITE-
TEMP, a small diverting valve must be piped into the
loop return downstream of the recirculating pump
(See Fig. 3-1C). This device is used to divert
recirculated water back to the heater for reheating if
the temperature of the water drops too low due to no
hot water demand from the system plus piping
radiation losses (See page 9 for operation
explanation). Be sure to pipe in unions and isolation
valves to facilitate diverting valve removal required
when element replacement is needed. A throttling
type valve should be installed in a full return line size
bypass around the diverting valve in order to
balance the flow to the diverting valve. This is
especially needed when recirculating pumps are large
oroversized.
Pop-Off Valve
Installation Instructions
1. Thread relief valve into the 1/4" NPT port located
on the lower diaphragm half near the spring
chamber. See drawing 4-1.
2. Tighten with a 3/4" wrench. Warning: Do Not
Over Tighten. Distortion can result causing the
relief valve not to seat.
Note: The discharge of the relief valve is 1/4" FPT and
can be piped over to a drain to prevent the relief
valve discharge from going onto the floor
underneath the Flo-Rite-Temp.
Note: The function of this pressure relief valve is to
relieve any excess pressure on the water side of
the Flo-Rite-Temp resulting from system water
hammer or water expansion pressure due to
water heating. If the problem is severe, water
hammer arrestors should be placed on all
equipment with fast closing water valves.
Expansion tanks should be used for all
expansion pressure problems. The relief set
point of this valve is 165 psig.
Note: The Armstrong Flo-Rite-Temp comes supplied
with a 1/4" NPT water pressure relief valve.
The standard valve has a cracking pressure of
165 psig. Installation instructions (AY-700) are
supplied with each heater. The valve is a self
relieving and self seating valve which will open
due to thermal expansion or hydrolic shock.
Continuous or intermittent discharge of this
valve while heater is in service could indicate a
system pressure problem. See note for
(Figure 3-1F) expansion tanks on previous page
possible solutions.
Note: For hard water applications, pipe pop-off
valve into a dirt leg.
Drawing 4-1.

5
See Fig. 3-1E for location of each option within the
system. All options would be installed downstream of the
water heater in the outgoing recirculation loop, if one is
present, or downstream of the hot water thermal loop if
recirculation is not used but always before the first hot
water take off from the system.
Option #1 A temperature relief valve set at roughly
15-30degreesabovethatoftheFLO-RITE-TEMPwillhelp
prevent any chance of overheated water reaching the
faucets.(NOTE:Normallyunitwillfailclosedandeitherno
wateroronlycoldwaterwillflowfromtheunit.)
OPTIONAL SAFETY EQUIPMENT
Option #2 A 3-way blending valve with a set point 10-
30degreesabovethatoftheFLO-RITE-TEMPwillhelp
prevent the chance of overheated water reaching the faucets
in the event of unit failure. Under normal operating
conditions the hot water flows straight through the blending
valve from Port B to Port A. But in the event of an
overheated situation, the blending valve will open Port C to
add sufficient cold water to maintain a constant temperature
. (NOTE: The blending valve should be sized to handle the
maximumflowofthesystem).
Note: The Armstrong Flo-Rite-Temp comes supplied with a 1/4" NPT water pressure relief valve. The standard valve has a
cracking pressure of 165 psig. Installation instructions (See AY-700) are supplied with each heater. The valve is a self
relieving and slef seating valve which will open due to thermal expansion or hydrolic shock continous or intermiten
discharge of this valve while heater is in service could indicate a system pressure problem. See note for (fig. 31F) on
previous page for possible solution.
Option#3 A temperatureswitchinstalled welldownstream
of the Flo-Rite-Temp outlet on a non-recirculated system or
just into the outgoing recirculated system loop on a
recirculated system, with a set point 15-30 degrees above
thatof the FLO-RITE-TEMPwillhelp prevent thechanceof
overheated water reaching the faucets in the event of
system problems. This switch can be used to turn off the
steam supply to the heater in the event of overheating. The
most economical way to accomplish this is with a solenoid
on the PRV. A full ported motorized valve on the steam
supply line may also be used. Option 3B. Along these
same lines, a pressure switch installed in the inlet water line
would shut down the supply steam on the heat exchanger
in the event of water pressure loss, preventing thermal
shock and water hammer to the unit.
Option #1
Loop or System
Thermometer
Temperature
Relief Valve
Hot Water from
Flo-Rite-Temp
Option #2
Loop or System
Thermometer
3-Way
Thermostatic
Valve
Cold Water Supply
To Flo-Rite-Temp
Hot Water from
Flo-Rite-Temp
Option #3
Cold Water Supply to
Flo-Rite-Temp
Temperature
Switch
Loop or System
Thermometer
Option 3A
Option 3B
Pressure Switch
Hot Water Supply From
Flo-Rite-Temp
To Steam
Shut-Off Valve
!
To steam
shut-off valve

6
Option #4 (Available only when a pressure reducing
station is installed on the Flo-Rite-Temp). Using the
Model GP-2000W1P system, when piped as shown in the
Option 4 drawing, will provide a safe dependable shut
down of the main steam valve when the water pressure
failsor drops rapidlyonthe Flo-Rite-Temp. Unlikea
solenoid application, which shuts the steam down when
the water pressure drops below a pre-set point, the GP-
2000W1P offers another benefit that it allows the system
to keep producing hot water even when the water pressure
isbelow theset pressure. TheGP-2000W1P Combination
valve essentially lets the steam pressure modulate below
the water pressure by 2 or 3 pounds, allowing a water
heater to supply hot water even when water pressure is
low.
Incoming cold water is piped into the hot water heater with
asample line pipedtothe W-1 PilotofGP-2000W1P. At
the same time the cold water is supplying the water heater,
its pressure it is also supplying the W-1 Pilot. When the
pressure of the incoming cold water decreases, the W-1
Pilot modulates down the supply of steam to the pressure
pilot controlling the main steam valve, acting as a non-
electric self-controlled shutdown device. Ultimately, this
valve eliminates the use of any electricity and gives the
customer safe control of their hot water supply when water
pressure loss or fluctuating water pressure conditions
exist.
Option #4
IMPORTANT UNIT START-UP AND
SHUTDOWN PROCEDURES
Itsimportanttorememberthatwaterpressuremust
ALWAYSbegreaterthansteampressureontheunitto
avoidboilingthewaterinthetubesoftheheatexchanger.
Whenstartingupa FLO-RITE-TEMPitisvery
importantthatthewatersupplyisturnedontotheunit
beforeanysteamisturnedon.Oncetheunitisupand
running,theinletwatervalveshouldneverbeclosed
unlessthesteamisturnedofffirst.Whenshuttingdowna
unityoushouldalwaysfirstshutoffthesteamandthen
allowwatertorunthroughtheunituntilithascooledand
completelycondensedallremainingsteamintheheat
exchangerbeforeclosingoffthesupplywatertotheunit.
ADJUSTING PROCEDURES
AllmodelsofFLO-RITE-TEMP’shavetwosettings
which need to be made on initial start-up. One setting must
be made at low flow while the other is made at high flows.
IMPORTANT:Oncethelowandhighflowadjustments
havebeenmade,theunitgenerallyneednotbeadjusted
againunlessyouroperatingconditionschangeora
differentsetpointisdesired.Asignificantdropin
temperatureoutputorcapacityisanindicationofabad
diaphragmorthatthetubebundleneedstobecleaned. Do
notreadjustthevalveunlessisolationoftheunitfromthe
systemandrunningwatertodrainproducespoor
temperaturecontrol. Ifcapacityisminimal,checkthe
diaphragmorcleanthebundlebutdonotreadjustthe
controlvalve.
START-UP AND ADJUSTING
PROCEDURE FOR MODEL 415
1. Before turning onthesteamtotheFLO-RITE-TEMP,
begin by opening the water supply valve to the unit
and checking for water leaks at the unit or any of the
associated piping.
2. If the unit is connected to a system which has a
recirculation loop and pump, be sure the pump is
turned off and the isolation valve on the leg of piping
going from the diverting valve back to the inlet of
theFLO-RITE-TEMP is closed(thisis the isolation
valve downstream of port “B” of the thermostatic
divertingvalve). (SeeFig.3-1)
3. Close the isolation valve on the hot water outlet of
the unit and open full and close several times the
throttling bypass valve to drain to purge all the air
fromtheFLO-RITE-TEMP.(SeeFig.3-1B). This
process also primes the units lower diaphragm area
withwater.Failuretodothispriortoinitial
adjustmentcanresultininaccuratesettingsand
poorresults.
Steam
Hot Water
Outlet
Cold Water
Inlet
Condensate

7
10. Tomake thehighflowadjustment,SLOWLYincrease
the flow of water through the unit to drain while
monitoring the outlet thermometer. When the outlet
temperature has dropped by approximately 10 °F
below set point for a Model 415E, make your high
flowadjustmentwhilemaintainingthatflow.
11. Place a small screw driver or center punch through
the hole in the high flow adjustment stem (see Fig.
7-1)and turn itina clockwisedirection. Thiswill
start to close the valve restricting the cooling water
and cause the outlet water temperature of the unit to
rise. Continue until the outlet temperature is back up
to your required set point.
(IMPORTANT-Whenmakingthehighflow
adjustmentthelowflowadjustmentSHOULDNOT
rotatewiththehighflowadjustment.Ifitdoes,you
willhavetoholditstationarywhilemakingyour
highflowadjustment).
12. The unit is now adjusted.
(IMPORTANT-Ifforanyreasonyoumustreadjust
theunit,youwillfirsthavetoreturnthehighflow
adjustmentbacktoitsfulluppositionasstatedin
point#7).
START-UP AND ADJUSTING
PROCEDURE FOR MODEL 535EP,
665SEP and 8120
Follow all the steps 1-6 as stated in the adjustment
procedures of the model 415.
7. Locate the low flow temperature adjustment (LFT)
and the high flow temperature adjustment (HFT) on
top of the mixing valve hidden under the hex
bonnet (See Fig. 7-1). Before beginning
adjustments, check to make sure the LFT is fully
closed. To do this, turn the LFT clockwise until it
stops. Also make sure the HFT is fully open. To do
this start by pressing down on the HFT when water
pressure is present on the unit and there is no water
flow through the unit. The HFT should only depress
about 1/8". If it pushes in further, turn the HFT stem
counter clockwise to open. Check every turn until
there is only 1/8" travel to the HFT when pushed
Figure 7-1
High Flow Adjustment (HFT)
Low Flow Adjustment (LFT)
Top Of Mixing Valve
!
!
4. Throttle the bypass valve to drain so that a constant
3 gpm of flow may pass to drain.
5. Slowly open steam valve or adjust the pressure
reducing valve to allow 2 - 15 psig of steam pressure
on the unit
(CAUTION:alwaysmakesurethereiswater
pressureontheunitbeforeaddingsteam.Failureto
dothiswillcauseseverehammeringoftheunitand
possibledamage).
6. Make sure that the steam trap draining the unit is
functioning properly and allow the entire unit to
come up to temperature for at least three to five
minutes while passing the 3 gpm of water flow to
drain before beginning the adjustment of the unit.
7. Locate the low and high flow adjustments on top of
the mixing valve hidden under the hex bonnet (see
Fig. 7-1). Before beginning adjustments, check to
make sure the high flow adjustment is fully open. To
do this start by pressing down on the high flow
adjustment when water pressure is present on the
unit and there is no water flow through the unit. This
should only depress about 1/8". If it pushes in
further, turn the adjustment stem counter clockwise
to open. Check every turn until there is only 1/8"
travel to the high flow stem when pushed down
(Note: with water pressure on the unit the stem
should pop back up after depressing it). If the high
flow adjustment stem will not depress at all the valve
is opened too far and you must turn the adjustment
clockwise until there is 1/8" travel downward to the
stem.
8. With the unit now isolated from the hot water system
and all flow of water being directed to drain at 3
gpm,letthe temperature stabilize.
9. Monitor the outlet temperature on the gauge located
in the bypass to drain (see Fig. 3-1B). Place an
adjustable wrench on the flats of the low flow
adjustment(seeFig.7-1).
Turning clockwise raises the discharge temperature
and counter-clockwise lowers the discharge
temperature. Make the appropriate adjustment to
achieve the desired set point. For example if a set
point of 140 °F is desired and the temperature reading
is 155 °F, you must turn the low flow adjustment
counter-clockwise to lower the set point temperature
from155°Fdownto140°F.
(IMPORTANT-Whenmakingthelowflow
adjustmentthehighflowadjustmentshaftSHOULD
rotatewiththelowflowadjustment.Ifitdoesnotdo
so,youwillhavetoturnitbyhandwhilemakingthe
lowflowadjustment). Allowtheunittostabilizeto
be sure that the unit will remain at the desired set
point. The low flow is now adjusted and should not
be readjusted.

8
(IMPORTANT: If, for any reason, you must
readjust the unit, you will first have to return the
LFT adjustment to the fully closed position as
stated in step 8).
CAUTION
Whenputtingaheavyloadontheheatexchanger,
watchthesteampressuregauge.Thispressureshouldnot
bepermittedtofallbelow2psig.Ifitdoesandseverewater
hammerdevelops,reducetheloadbyclosingsomeofthe
faucetsorshutthesystemdown.Whensteampressure
dropsunderheavyloadandhammeringoccurs,not
enoughsteamisgettingtotheunit. Thiscan bearesult
ofanundersizedreducingvalve,lackofboilercapacityor
restrictivesteamlines. Hammeringcanalsobecausedby
alossofwaterpressurewherethewaterpressureinthe
unitfallsbelowthepressureofsteam.Thisconditionis
usuallycausedbyimpropershutdownoftheunitor
someoneclosingtheinletwatervalvewiththesteam
pressurestill on theunit.
down (Note: with water pressure on the unit the stem
should pop back up after depressing it). If the HFT
stem will not depress at all the valve is opened too
far and you must turn the adjustment clockwise until
there is 1/8" travel downward to the stem.
8. With the unit now isolated from the hot water system
and all flow of water being directed to drain, slowly
increase the water demand to approximately 3/4 of
the maximum capacity according to the capacity
chart on page 13. When starting a cold system, you
should take at least 2 to 3 minutes to slowly increase
to this demand. This will allow time for the steam
piping feeding the unit to come up to temperature,
pressure and purge itself of excess condensate.
9. Place a small screwdriver or center punch through
the hole in the HFT adjustment and slowly turn the
HFT to change the temperature to the desired set
point. Close (clockwise) the HFT to raise the outlet
water temperature. Allow adequate time for the
water temperature to stabilize. This could take
several minutes if the piping is cold and the
measurement point is far from the unit.
(IMPORTANT: When making the HFT
adjustment, the LFT adjustment SHOULD NOT
rotate with the HFT adjustment. If it does, you
will have to hold it stationary while making your
HFT adjustment).
10. Lower the water flow rate to 3 gpm. The LFT
adjustment is currently fully closed (see step 8).
Slowly open (counterclockwise) the LFT to lower
the outlet water temperature to the desired set point.
Allow adequate time for the temperature to
stabilize.This will take longer since the flow rate is
so small.
(IMPORTANT: When making the LFT
adjustment, the HFT adjustment shaft SHOULD
rotate with the LFT adjustment. If it does not do
so, you will have to turn it by hand while making
the LFT adjustment).
11. Recheck the outlet water temperature at 3/4 of the
maximum demand it will see. Adjust if necessary.
Opening the HFT (counterclockwise) will lower the
temperature and closing the HFT (clockwise) will
raise the temperature. Note: You may want to fine
tune the HFT adjustments during normal operation
of the unit at heavy demand. If outlet temperature is
slightly low, turn HFT clockwise to raise it. This
should only be done during the initial service of the
unit or when the unit has been cleaned. Never
attempt to re-adjust the unit with a dirty tube bundle
- always clean tube bundle first. The unit is now
adjusted.

9
Three-way Thermostatic Capsule - This
device has a set point roughly 20 degrees below the
set point of the FLO-RITE-TEMP and will maintain
the temperature in the loop between the set point of
the capsule and the set point of the FLO-RITE-
TEMP. The capsule senses the temperature of the
recirculated water and compares it with its pre-set
temperature. If the temperature in the loop drops
below the capsule's set point because of radiation loss
from the piping and no hot water demand from the
loop, then the capsule begins to divert some of the
loop's flow to the inlet of the FLO-RITE-TEMP
(ports A to B) for reheating. This diversion will bring
the temperature of the loop back up to its required
temperature. Once the temperature in the loop is
over the capsule’s set point all flow from the recircu-
lation pump now goes straight through the capsule
(ports A to C) and the return water is fed back to the
hot water supply line. To regulate flow to the cap-
sule, a balancing/bypass line with globe valve is
required.
Thisdivertingrecirculatingsystemeliminates
the need for aquastats and any electrical wiring. It is
a self contained, self regulating system that controls
the temperature of the water in the loop during low or
no hot water demand situations. When there is a
demand for hot water the temperature of the water
introducedintothesystem is instantly controlledby
the FLO-RITE-TEMP feed forward mode of operation.
Fig. 9-1
Recirculation
Pump
Capsule Balance
Line
Globe Valve
Loop or System
Thermometer
Bypass to drain
Unit Setting Thermometer
3-Way Thermostatic Capsule
A
C
B
FLO-RITE-TEMP
Recirculation System Piping and Operation
Because of its relatively small size and compact-
ness, the FLO-RITE-TEMP can easily be installed
close to the point of water use eliminating the need for
a recirculation system.
In applications where water heaters are located
in basements or utility rooms and feed an entire
building or wing a recirculation system or loop must
be utilized to assure instantaneous hot water to all
usage points.
The recirculation system is made up of several
differentcomponents designedtowork togetherto
maintain the temperature of the water in the loop at
times of low or no flow.
Recirculation pump - This is a constant GPM
pump that runs continuously regardless of the hot
water demand from the loop. Its function is to
continually recirculate the water in the loop in order
to maintain the temperature during low or no flow
conditions. As a rule of thumb, the capacity of the
pump should be approximately 10 to 15 percent of the
maximum capacity of the FLO-RITE-TEMP and be
able to overcome any head found in the loop. The
recirculation pump however, may be larger than 15
percent. But when a larger pump is used, a full line
size bypass with a globe valve must be piped to divert
most of the flow around the thermostatic capsule.

10
In operation, hot water is drawn off the top of the
tank at the same time as cold water enters from the
bottom and hot water from the FLO-RITE-TEMP
enters the tank from the side. When the peak load
stops and the aquastat senses the cooler water in
the tank, the pump starts and the heating process
begins another cycle.
A bypass line from the heater to the hot water
demand is shown and is normally kept closed. When
the accumulator tank requires maintenance this
bypass allows the tank to be isolated, with hot water
beingsupplied by the FLO-RITE-TEMP only.
Advantages of the accumulation system are:
!Accumulation tank temperatures are restored over
a period of time avoiding large intermittent steam
demands.
!Providing the FLO-RITE-TEMP's safety features
to the entire system.
!Providing accurate hot water temperature control.
!Providing a back up alternative during tank
maintenance.
!To allow accumulator tanks to be relatively small
in size because hot water demand is supplemented
by the FLO-RITE-TEMP.
FLO-RITE-TEMP-Accumulation System
For peak load conditions or to avoid large intermittent steam demands
The FLO-RITE-TEMP water heater accumula-
tion system is designed to provide a specified volume
of accumulated hot water for short duration peak
loads or when steam is in short supply and a recovery
time can be tolerated. During periods of low or no
demand, the water in the accumulator tank is heated
to the set point temperature by the FLO-RITE-TEMP
water heater.
An accumulator or large storage tank is installed
in series with the FLO-RITE-TEMP water heater.
Cold water is piped to the inlet of the water heater
and into the bottom of the accumulator tank. Hot
water flows from the FLO-RITE-TEMP directly to
the accumulator tank through a pump that is con-
trolled by an aquastat. When the pump is off the flow
goes to the accumulator via a bypass around the
pump. This would occur when there is hot water
demand and the temperature in the tank is at set
point.
When the system is started the water in the
accumulator tank is cold which causes the aquastat to
turn the pump on. Water flows out of the bottom of
the tank to the inlet of the FLO-RITE-TEMP. The
water continues this cycle until the aquastat in the
tank senses theappropriate temperature. At that time
the pump shuts off and the water is ready for use.
The globe valve on the bottom of the accumulator
tank should be adjusted at full system demand so that
a pressure differential of approximately 8 psi is read
across the FLO-RITE-TEMP.
Fig. 10-1

11
Flo-Rite-Temp Tempered Water Systems
For Safety Shower/Eye Wash Stations
The problem which faces many companies
today is how to safely warm water to be used
effectively in a drench shower or safety shower
situation.
Storage tank units can run out of warm water
causing people to go into possible shock due to cold
water exposure or to end the shower before proper
flushing has taken place. Also, because the water in
the tank is only heated to a temperature range of 65
to 95 degrees F. there is the potential and risk of
legionella bacteria forming inside of the tank. Lastly,
tank systems are feedback systems which can cause
severe overheating of the water when thermostatic
elementsfail causingpersonalinjury.
The solution is to use the Armstrong Flo-Rite-
Temp tankless instantaneous feedforward water
heater in series with a self-contained fail safe thermo-
staticmixingvalve.
How The System Works
The system, when piped as shown in the
drawing, will provide a safe, continuous and depend-
able source of accurately controlled warm water.
Incoming cold water is heated between 120 to
130 degrees F by the Flo-Rite-Temp. (The unit is set
to provide a constant supply of hot water at an
adjusted set point within this temperature range,
usually the lowest set point of 120Odegrees is used).
The 120°F water can be piped to the Rada Z358
thermostaticmixingvalve which willblendcold water
with the 120°F water to make the tepid water for the
safety shower/eye wash station. The Rada Z358
valve is equipped to allow cold water to the
showerhead in the event of hot water failure.
The Rada Z358 Mixing Valve (see Bulletin
ALIB-Z358-20) properly proportions the hot and cold
incoming water to obtain a preset delivery tempera-
ture to the drench shower head. Demand induced
changes are sensed and automatically compensated
for by the valve so that shower output temperature
remains constant. A recirculation system may also
be incorporated in this system and is especially
recommended in applications where shower lines are
exposed to the cold air or shower heads are a dis-
tance from the heater.
Feedforward control in the water heater elimi-
nates the danger of thermostatic element failure and
overheating typical in storage tank feedback systems.
Because there is no storage tank, there is no danger
of legionella forming in the stored warm water. All
water is heated instantaneously on the spot, there is
no shortage of heated water or shower time limits.
Option 1: Water recirculation when heater is servicing a long run to the shower head, more than one shower
head, or piping is exposed to cold ambient temperatures
Fig. 11-1

12
Fig. 12-1
Table 12-3. Specifications
Table 12-1. Dimensions & Weights
Note: ** There is an open vent to atmosphere between the tube sheets to detect tube failure.
Model 415 and 535 Profile Shown (665 and 8120 valve shows that connections for water inlet and outlet are on
opposite sides of the valve body).
Table 12-2 Materials
Single Wall and Double Wall Profile
ABC D EFGHJKLM 1 2 3
415 in
mm
54
1372
4-1/2
114
7-1/2
190
7
178
4-1/2
114
3-1/2
89
3-1/2
89
7
178
5
127
6-1/4
159
50
1270
7-1/2
190
1" NPT
25
3/4" NPT
20
2" NPT
50
lb
k
g
133
60
535 in
mm
67-1/2
1715
5-1/4
133
8-5/8
219
9
229
5-9/16
141
4
102
4-1/2
114
7-7/8
200
6
152
7-1/2
191
62
1575
9
229
1-1/2" NPT
40
1" NPT
25
2-1/2" NPT
65
lb
k
g
235
107
665 in
mm
82
2083
5-3/4
146
10-3/8
264
10-3/8
264
6-5/8
168
4-3/4
121
5-1/2
140
9-1/4
235
7-1/2
190
8-3/4
222
74
1880
11
280
2" NPT
50
1-1/4" NPT
32
3" NPT
80
lb
k
g
358
162
8120 in
mm
85
2159
5-3/4
146
11-3/4
299
12
305
8-5/8
219
6-1/8
156
8-7/8
225
9-1/2
241
8
203
9-1/2
241
74
1880
12-3/8
314
3" NPT
80
2" NPT
50
4" 150# ANSI
100
lb
k
g
585
265
415DW in
mm
76-1/8
1934
4-1/2
114
7-1/2
190
7
178
4-1/2
114
3-3/8
86
3-3/4
95
10-1/2
267
5
127
6-7/8
175
75
1905
7-1/2
190
1" NPT
25
3/4" NPT
20
2" NPT
50
lb
k
g
199
90
535DW in
mm
77-3/8
1965
5-1/4
133
8-5/8
219
9
229
5-9/16
141
4
102
4-1/4
108
11-1/2
292
6
152
8-1/8
206
75
1905
9
229
1-1/2" NPT
40
1" NPT
25
2-1/2" NPT
65
lb
k
g
270
122
665DW in
mm
90-5/8
2302
5-3/4
146
10-3/8
264
10-3/8
264
6-5/8
168
4-3/4
121
5
127
11-3/4
298
7-1/2
191
9-3/4
248
87
2210
11
280
2" NPT
50
1-1/4" NPT
32
3" NPT
80
lb
k
g
444
201
8120DW in
mm
79-7/8
2029
5-3/4
146
11-3/4
298
12
305
8-5/8
219
6
152
8-3/4
222
12-5/8
321
8
203
11-5/8
295
75
1905
12-3/8
314
3" NPT
80
2" NPT
50
4" 150# ANSI
100
lb
k
g
665
302
Table 12-1. Dimensions and Weights
Dimensions Connections Wt.Model
Body Valve Valve Seats Diaphragm
Heat
Exchanger
Shell
Heat Exchanger
Tubes
Tube
Sheets**
Tube
Bundle
End Ca
p
(415) 303 Stainless Steel
with Teflon Inserts
(415/535) 303
Stainless Steel
(535/665/8120) Brass (665/8120) Brass
(415DW) 303 SS with
Teflon Inserts
(415DW/535DW)
303 SS
535DW/665DW/8120DW
Brass
(665DW/8120DW)
Brass
Brass
N/A
Steam Side
Steel/Water
Side Brass
Carbon Steel
ASME "U"
Stamped
5/8" 16 BWG
Admirality Brass
5/8" Copper Inner
Tube 3/4" I.D.
Grooved Copper
Outer Tube
Brass
Bronze
Single WallDouble Wall
Viton
®
GF
Reinforced with
Nomex
®
Fiber
Application Steam Supply Pressure Water Supply Pressure Maximum Water Pressure Drop
Steam to Water 2 - 15
p
si
g
(
0.14 - 1.0 bar
)
20 - 125
p
si
g
(
1.4 - 8.5 bar
)
10
p
si
g
(
0.7 bar
)

13
CAPACITIES AND STEAM LOADS
FLO-RITE-TEMP
Table 13-1
*Units may be piped in parallel when desired capacities exceed that of a single unit.
Notes: Minimum water temperature increase is 60°F (33°C). Consult factory if less than 60°F (33°C) increase in required or a set
temperature of below 120°F (49°C) is required. See Armstrongs All Products Catalog 326 for proper pressure reducing valve
selection.
psig psig psig psig psig psig psig psig bar bar bar bar bar bar bar bar
2 5 10 15 2 5 10 15 0.14 0.35 0.7 1 0.14 0.35 0.7 1
lb/hr lb/hr lb/hr lb/hr lb/hr lb/hr lb/hr lb/hr m3/h m3/h m3/h m3/h kg/hr kg/hr kg/hr kg/hr
17 18 20 20 714 767 839 901 3.8 4.1 4.5 4.5 323 347 379 407 415
37 40 43 45 1543 1657 1814 1946 8.4 9.1 9.8 10.2 697 749 820 880 535
69 74 80 80 2855 3067 3356 3601 15.7 16.8 18.2 18.2 1290 1386 1517 1628 665
142 145 145 145 5680 6160 6760 7160 32.2 32.9 32.9 32.9 2576 2794 3066 3248 8120
15 16 17 18 681 734 807 868 3.4 3.6 3.8 4.1 308 332 365 392 415
32 34 37 39 1472 1587 1743 1876 7.3 7.7 8.4 8.8 665 717 788 848 535
58 63 68 73 2723 2936 3226 3472 13.2 14.3 15.4 16.6 1230 1327 1458 1569 665
112 122 136 145 5040 5490 6120 6705 25.4 27.7 30.9 32.9 2286 2490 2776 3041 8120
12 13 15 16 646 700 773 835 2.7 3.0 3.4 3.6 292 316 349 377 415
27 29 32 34 1397 1513 1671 1804 6.1 6.6 7.3 7.7 631 684 755 815 535
50 54 59 63 2585 2799 3091 3338 11.3 12.2 13.3 14.3 1168 1265 1397 1509 665
88 97 109 120 4400 4850 5450 6000 20.0 22.0 24.7 27.2 1996 2200 2472 2722 8120
9 10 11 12 572 627 702 765 2.0 2.3 2.5 2.7 259 283 317 346 415
20 22 24 26 1235 1355 1517 1652 4.5 5.0 5.5 5.9 558 612 686 747 535
37 40 45 48 2286 2508 2806 3057 8.4 9.1 10.2 10.9 1033 1134 1268 1382 665
69 83 89 95 4140 4980 5340 5700 15.6 18.8 20.0 21.6 1878 2259 2422 2585 8120
5 5 6 7 344 386 441 487 1.1 1.1 1.4 1.6 156 175 200 221 415
12 13 15 16 861 966 1104 1219 2.7 3.0 3.4 3.6 390 438 501 553 535
23 26 29 32 1663 1866 2134 2355 5.2 5.9 6.6 7.3 754 846 968 1068 665
43 47 52 59 3010 3290 3640 4130 9.7 10.7 11.8 13.4 1365 1492 1651 1873 8120
19 20 20 20 692 745 816 877 4.3 4.5 4.5 4.5 313 337 369 396 415
41 44 45 45 1495 1609 1764 1896 9.3 10.0 10.2 10.2 676 727 797 857 535
76 80 80 80 2767 2977 3264 3508 17.3 18.2 18.2 18.2 1251 1346 1475 1586 665
145 145 145 145 5740 6090 6580 7035 32.2 32.2 32.2 32.2 2603 2762 2985 3191 8120
16 17 19 20 660 712 785 846 3.6 3.8 4.3 4.5 298 322 355 382 415
34 37 40 43 1425 1539 1695 1827 7.7 8.4 9.1 9.8 644 696 766 826 535
64 68 75 80 2637 2848 3137 3381 14.5 15.4 17.0 18.2 1192 1287 1418 1528 665
127 138 145 145 5080 5520 6120 6760 28.8 31.3 32.2 32.2 2304 2504 2776 3066 8120
13 14 16 17 626 679 752 813 2.9 3.2 3.6 3.8 283 307 340 367 415
29 31 34 37 1352 1467 1624 1756 6.6 7.0 7.7 8.4 611 663 734 794 535
54 58 64 68 2502 2715 3005 3250 12.2 13.2 14.5 15.4 1131 1227 1358 1474 665
99 108 121 134 4455 4860 5445 6030 22.5 24.5 27.5 30.4 2021 2204 2470 2735 8120
10 11 12 13 553 608 682 744 2.3 2.5 2.7 3.0 250 275 308 336 415
21 23 25 28 1194 1313 1473 1607 4.7 5.2 5.7 6.4 540 593 665 726 535
39 42 47 51 2210 2429 2725 2974 8.9 9.5 10.7 11.6 999 1098 1232 1344 665
76 90 95 102 4180 4950 5225 5610 17.2 20.4 21.6 23.1 1896 2245 2370 2545 8120
7 6 6 7 332 373 428 473 1.1 1.4 1.4 1.6 151 169 194 214 415
12 14 16 17 831 934 1071 1185 2.7 3.2 3.6 3.9 377 424 486 537 535
24 27 30 33 1605 1805 2069 2289 5.4 6.1 6.8 7.5 728 819 938 1037 665
49 55 63 72 3185 3575 4095 4680 11.1 12.5 14.3 16.3 1445 1622 1857 2123 8120
18 19 20 20 638 690 762 822 4.1 4.3 4.5 4.5 288 312 344 372 415
38 41 45 45 1378 1491 1646 1777 8.7 9.3 10.2 10.2 623 674 744 803 535
70 76 80 80 2550 2760 3046 3288 15.9 17.3 18.2 18.2 1152 1247 1377 1486 665
145 145 145 145 5110 5565 6090 6510 32.2 32.2 32.2 32.2 2318 2524 2762 2953 8120
15 16 17 19 605 658 729 790 3.4 3.6 3.8 4.3 273 297 330 357 415
32 34 38 40 1307 1421 1576 1708 7.3 7.7 8.6 9.1 591 642 712 772 535
58 63 69 75 2418 2629 2917 3160 13.2 14.3 15.7 17.0 1093 1188 1318 1428 665
111 123 137 145 4440 4920 5480 6080 25.2 27.9 31.1 32.2 2014 2232 2486 2758 8120
10 11 13 14 533 588 661 723 2.3 2.5 2.9 3.2 241 266 299 327 415
22 24 27 30 1152 1270 1428 1561 5.0 5.5 6.1 6.8 521 574 645 703 535
41 45 50 55 2132 2349 2642 2889 9.3 10.2 11.3 12.5 964 1062 1194 1306 665
85 99 104 115 4250 4950 5200 5750 19.3 22.5 23.6 26.1 1928 2245 2359 2608 8120
5 6 7 7 320 360 414 459 1.1 1.4 1.6 1.6 145 163 188 208 415
13 14 16 18 800 902 1037 1150 3.0 3.2 3.6 4.1 363 409 470 522 535
25 28 32 35 1546 1743 2004 2221 5.7 6.4 7.3 7.9 701 791 909 1007 665
59 67 80 90 3540 4020 4800 5400 13.4 15.2 18.1 20.4 1606 1823 2177 2449 8120
Model
16
54
60
71
82
10
49
54
60
71
82
4
49
54
60
71
82
Inlet
Temp.
°C
Set
Temp.
°C
Standard
Hot Water Capacities* Steam Capacities
Steam Pressure Steam Pressure
140
160
40
50
60
140
160
180
130
Inlet
Temp.
°F
Set
Temp.
°F
180
120
130
140
160
180
120
130
Hot Water Capacities*
Steam Pressure
Standard
Steam Capacities
Steam Pressure

14
TROUBLESHOOTING GUIDE
Table 14-1
DISASSEMBLY
Control Valve - All maintenance on the valve should be done by a factory trained product specialist
with the exception of replacing the pressure sensing diaphragm. To replace the diaphragm remove all nuts and
bolts from the bottom cover. After removing the bottom cover, remove the lock nuts from the bottom of the
valve shaft. You will need to hold the platter to prevent the assembly from spinning, or hold the stem with
large a slotted screw driver in the slot at the bottom of the stem. After removing the nuts, slide the platter off,
then the old diaphragm, being careful not to lose the brass washer above the diaphragm. To reassemble follow
the reverse order. Make sure when tightening the cover bolts that you use a criss-cross pattern.
Problem Causes Solutions
The steam is not turned on to the unit. Open steam valve to the unit.
The water tubes in the heat exchanger are
plugged.
See Clean-In-Place operating instructions or remove
tube bundle and clean.
The differential pressure sensing diaphragm
is ruptured. Replace the diaphragm.
The mixing valve is not properly adjusted. Adjust the unit according to the instructions.
The steam pressure is too low. Increase steam pressure (2 - 15 psig).
Air has accumulated in the shell of the heat
exchanger. Install a thermostatic air vent on the shell.
The flow is above the rated capacity of the
unit. Make sure unit is sized properly.
The tubes in the heat exchanger are scaled. See Clean-In-Place operating instructions or remove
tube bundle and clean.
The mixing valve is not properly adjusted. Adjust the unit according to the instructions.
The steam pressure is too high. Decrease steam pressure (2 - 15 psig).
Recirculated water is continually diverting
through the Flo-Rite-Temp.
Check diverting valve for a stuck or failed thermal
capsule.
The steam is superheated. Pipe to saturated steam.
The mixing valve is not properly adjusted. Adjust the unit according to the instructions.
The inlet valve on the water supply is closed. Open valve.
There is no demand for hot water. Wait till demand is present then re-check.
The shell of the heat exchanger is not
properly drained.
Make sure steam trap is working and properly installed.
Make sure shell is level to floor. Do not elevate
condensate if pressure is low.
The steam pressure has dropped or a
vacuum has formed.
Increase pressure and install vacuum breaker at shell
drain (Figure 1-1).
The water pressure had dropped below that
of the steam pressure and steam is forming
inside of the water tubes.
Install a pressure switch on water inlet to shut off steam
on a drop in water pressure.
The unit
hammers and
bangs during
operation.
Only cold water
comes out of
the unit.
Only warm
water comes
out of the unit.
Extreme hot
water comes
out of the unit.
No water
comes out of
the unit.

15
Single Wall Heat Exchanger - To remove the tube bundle for cleaning. Simply unbolt the mixing valve
from the shell and move it out of the way. The tube bundle can be pulled out from the valve end (see Table
12-1 for clearance dimensions). Once the tube bundle is out of the shell, unbolt the end cap on the floating
head end and remove to provide straight through cleaning. Reassemble in the reverse order (On the Model
665 dual stem unit when reassembling the tube bundle, make sure that the "TOP" indicator stamped on the
cover and both ends of the tube bundle line up and bundle is reinstalled in the shell with both "TOP" indicators
facing up). New gaskets will be required for this procedure. (Order heat exchanger gasket kit for model
number)
Fig. 15-1
NOTE: Depending on capacity requirements a parallel water heater installation may also require (2) two PRVs in
parallel. Single wall installation shown - Double wall would be similar. See your Armstrong Representative for
proper reducing valve application.
Steam In
Armstrong
Pressure Reducing
Valve (if req'd) Safety Relief
Valve
Steam Pressure
Gauge
Steam
Pressure
Gauge
Armstrong TVS Trap
I.B.
I.B.
I.B.
2-15 psig steam
in the shell
2-15 psig steam
in the shell
Armstrong
Tr a p
Armstrong
Tr a p
Armstrong
Tr a p
Vacuum
Breaker
Thermostatic
Air Vent
System Isolation
Valve
Bypass to
Drain for
Setting
Bypass to
Drain for
Setting
Setting
Thermometer
Setting
Thermometer
Thermal
Loops
Thermal
Loops
Heated
Water
Supply
Water
System
Isolation
Valve

16
When there is a noticeable drop in the Flo-Rite-
Temp’s — hot water capacity, temperature, or an increased
water pressure drop across the unit — tube bundle scale
removal should be considered using the commercially
available product called RITE-Qwik*.
Tube bundle scale removal can be accomplished as
follows:
Step 1 - Shut off steam supply valve #1 to the Flo-Rite-
Temp.
Step 2 - While the water pressure is still ON and the steam is
OFF, run the Flo-Rite-Temp for (10) ten minutes or until the
outside of the unit is cool to the touch.
Step 3 - Shut the water inlet valve #4 OFF and water outlet
valve #5 OFF; open cleaning connection outlet #7. Connect
air hose with regulator to valve #9. Turn air on slowly to
approximately 5 psi. Increase to maximum of 25 psi. Leave
air pressure on until water stops coming out of connection
#7. Turn air (valve #9) off. Open cleaning connection inlet #8
and remove the pop-off valve or inlet pipe plug #6 from the
lower diaphragm cover of the control valve . Let the
remaining water drain by gravity from the Flo-Rite-Temp.
Step 4 - After all the water has been drained, reinstall the
pop-off valve or pipe plug #6 into the lower diaphragm cover
of the control valve.
Step 5 - With hose valve closed connect return hose A of the
Clean-in-Place to the outlet cleaning connection #7 of the
Flo-Rite-Temp.
Step 6 - With hose valve closed connect discharge hose B of
the Clean-in-Place to the inlet cleaning connection #8 of the
Flo-Rite-Temp.
Step 7 - Start pump. Open ball valve of discharge hose B of
the Clean-in-Place.
Step 8 - Slowly open the ball valve on return hose A and
watch for foaming in the tank.
Step 9 - Clean-in-Place is now circulating cleaning solution
through the Flo-Rite-Temp. Periodically check the solution
to see if it has changed color or quit fizzing. If the cleaning
Clean-In-Place Operating Instructions
Flo-Rite-Temp Clean-In-Place
* RITE-QWIK is a non hazardous chemical cleaner which has been proven effective for removing deposits without
harming the FLO-RITE-TEMP internally.
35"
(889 mm)
Air Vent
Return
Hose 47"
(1194 mm)
Discharge
Hose
Drain
solution has stopped fizzing and has not changed color, the Flo-
Rite-Temp is clean. You may save the remaining unspent solution
for your next job. If the solution quits fizzing and the color has
changed, add new cleaning solution. Continue circulating in the
same manner as above. Do not exceed a maximum
circulation time of (3) three hours.
Step 10 - Shut-off pump. Close discharge hose valve B on
Clean-in-Place. Open air (valve #9). Turn air on slowly to
approximately 5 psi. Increase as Clean-in-Place fluid returns to
tank. (Maximum air pressure 25 psi.)
Step 11 - Leave air blow for approximately 3-5 minutes. This
should return most of the fluid to the tank. Close both hose
valves.
Step 12 - Disconnect return hose A from the Flo-Rite-Temp outlet
cleaning connection #7 and discharge hose B from the inlet
cleaning connection #8. Also remove the pop-off valve or pipe
plug #6 from the lower diaphragm cover of the control valve. Let
the cleaning solution drain by gravity from the Flo-Rite-Temp.
Step 13 - Close valve #2 going into the system and open valve
#3 going to the drain.
Step 14 - Open the water outlet valve #5 then open SLOWLY
inlet water valve #4. Let the water run for (1) one minute before
installing the pop-off valve or pipe plug #6 into the lower
diaphragm cover of the control valve.
Step 15 - After the pop-off valve or pipe plug #6 is installed, run
water into the drain for (5) five minutes to flush out all of the
cleaning solution. Throttle the outlet valve #3 open and closed to
purge the air from under the diaphragm.
Step 16 - After flushing the unit, close valve #3 and open the
steam supply valve #1 SLOWLY and let the Flo-Rite-Temp heat
up.
Step 17 - Set the Flo-Rite-Temp as needed. (This step may not
be necessary).
Step 18 - Open valve #2 to the system and monitor the system
until the temperature is back to normal.
Step 19 - After use, flush the pump with water to remove the
chemical to prevent seal deterioration.
2
5
36
9
8
7
4
1
Air

17
8120 Control Valve
16
17
18
19 20
21
22
23
24
25
26
27
28
29
30
31
1
2
3
5
6
7
810
33
9
11
12
13
32 14
15
665 Control Valve
16
17
18
19
20 21
22
15
14
32
13
12
11
24
25
26
28
29
30
31
1
2
3
4
5
6
8
9
23
Number Description
1 Spring Adjustment
2 Spring Housing
3Spring
4 Lower Diaphragm Cover
5 Diaphragm Bolt (12)
6 Diaphragm Nut (12)
7 Upper Diaphragm Cover
8 O-Ring 2-155
9 Lower Valve
10 O-Ring 2-147
11 Set Screw X2
12 Body
13 Stem
14 HFT Adjuster
15 Top Cap
16 Bonnet
17 O-Ring 2-121
18 O-Ring 2-111
19 Left Adjuster
20 Socket Cap Screw X13
21 O-Ring 2-157
22 Restrictor Assembly
23 O-Ring 2-144
24 Upper Valve Low Temperature
24 Upper Valve High Temperature
25 O-Ring 2-214
26 Stem Guide
27 O-Ring 2-162
28 Diaphragm
29 Diaphragm Supply Disc
30 Diaphragm Disc
31 Jam Nut (2)
32 Socket Cap Screw X1
33 Lower Valve Spacer
Listing of Parts
Number Description
1 Spring Adjustment
2 Spring Housing
3Spring
4 Lower Diaphragm Cover
5 Diaphragm Bolt (12)
6 Diaphragm Nut (12)
7 Upper Diaphragm Cover
8 O-Ring 2-155 X2
9 Lower Valve
11 Set Screw X2
12 Body
13 Stem
14 HFT Adjuster
15 Top Cap
16 Bonnet
17 O-Ring 2-121
18 O-Ring 2-111
19 Left Adjuster
20 Socket Cap Screw X11
21 O-Ring 2-147 X2
22 Restrictor Assembly
23 O-Ring 2-134
24 Upper Valve Low Temperature
24 Upper Valve High Temperature
25 O-Ring 2-214
26 Stem Guide
28 Diaphragm
29 Diaphragm Supply Disc
30 Diaphragm Disc
31 Jam Nut (2)
32 Socket Cap Screw X1
Listing of Parts

18
Number Description
1 Spring Adjustment
2 Spring Housing
3Spring
4 Lower Diaphragm Cover
5 Diaphragm Bolt (12)
6 Diaphragm Nut (12)
7 Upper Diaphragm Cover
8 O-Ring 2-153
9 Lower Valve
10 Lower Valve Disc
11 Retainer Nut
12 Body
13 Stem
14 HFT Adjuster
15 Top Cap
16 Bonnet
17 O-Ring 2-018
18 O-Ring 2-012
19 Left Adjuster
20 Socket Cap Screw X7
21 O-Ring 2-138
22 Restrictor Assembly
23 O-Ring 2-025
24 Upper Valve Assembly
25 O-Ring 2-210
26 Retainer
27 O-Ring 2-131
28 Diaphragm
29 Diaphragm Supply Disc
30 Diaphragm Disc
31 Jam Nut (2)
32 O-Ring 2-135
33 Socket Cap Screw X1
Listing of Parts
535 Control Valve 415 Control Valve
31
30
29
28
1
2
3
4
5
789
25
24
23
22
11
12
13
14 32
15
16
17
18 19
20
21
26
27
16
17
18
19 20
21
22
23
24
25
26
27
28
29
30
31
32
1
2
3
4
5
6
15
33
14
13
12
11
10
9
8
7
Number Description
1 Spring Adjustment
2 Spring Housing
3Spring
4 Lower Diaphragm Cover
5 Diaphragm Bolt (12)
6 Diaphragm Nut (12)
7 Upper Diaphragm Cover
8 O-Ring 2-155
9 Lower Valve Low Temperature
9 Lower Valve High Temperature
11 Set Screw X2
12 Body
13 Stem
14 HFT Adjuster
15 Top Cap
16 Bonnet
17 O-Ring 2-119
18 O-Ring 2-111
19 Left Adjuster
20 Socket Cap Screw X11
21 O-Ring 2-147
22 Restrictor Assembly
23 O-Ring 2-128
24 Upper Valve Low Temperature
24 Upper Valve High Temperature
25 O-Ring 2-214
26 Retainer
27 O-Ring 2-135 X2
28 Diaphragm
29 Diaphragm Supply Disc
30 Diaphragm Disc
31 Jam Nut (2)
32 Socket Cap Screw X1
Listing of Parts

19
Notes

Armstrong Hot Water Group
221 Armstrong Blvd., P.O. Box 408, Three Rivers, Michigan 49093 - USA Ph: [phone] Fax: [phone]
www.armstrong-intl.com
Bulletin No. AY-780-L 7/03 Printed in U.S.A.
Limited Warranty and Remedy
Armstrong-Yoshitake, Inc. (“Armstrong”) warrants to the original user of those products supplied by it and used
in the service and in the manner for which they are intended, that such products shall be free from defects in
material and workmanship for a period of one (1) year from the date of installation, but not longer than 15 months
from the date of shipment from the factory [unless a Special Warranty Period applies, as listed below]. This
warranty does not extend to any product that has been subject to misuse, neglect, or alteration after shipment
from the Armstrong factory. Except as may be expressly provided in a written agreement between Armstrong
and the user, which is signed by both parties, Armstrong DOES NOT MAKE ANY OTHER REPRESENTATIONS
OR WARRANTIES, EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, ANY IMPLIED WARRANTY
OF MERCHANTABILITY OR ANY IMPLIED WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE. The
sole and exclusive remedy with respect to the above limited warranty or with respect to any other claim relating
to the products or to defects or any condition or use of the products supplied by Armstrong, however caused,
and whether such claim is based upon warranty, contract, negligence, strict liability, or any other basis or
theory, is limited to Armstrong’s repair or replacement of the part or product, excluding any labor or any other
cost to remove or install said part or product, or, at Armstrong’s option, to repayment of the purchase price. As
a condition of enforcing any rights or remedies relating to Armstrong products, notice of any warranty or other
claim relating to the products must be given in writing to Armstrong: (i) within 30 days of last day of the
applicable warranty period, or (ii) within 30 days of the date of the manifestation of the condition or occurrence
giving rise to the claim, whichever is earlier. IN NO EVENT SHALL ARMSTRONG BE LIABLE FOR SPECIAL,
DIRECT, INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES, INCLUDING, BUT NOT LIMITED TO,
LOSS OF USE OR PROFITS OR INTERRUPTION OF BUSINESS. The Limited Warranty and Remedy terms
herein apply notwithstanding any contrary terms in any purchase order or form submitted or issued by any user,
purchaser, or third party and all such contrary terms shall be deemed rejected by Armstrong.
Special Warranty Periods are as follows:
Flo-Rite-Temp Instantaneous Water Heater—The tube bundle shall have a 10-year guarantee against failure
caused by materials or workmanship provided by Armstrong but not against gasket failure or damage caused
by corrosion, water hammer or lack of proper cleaning.
Flo-Rite-Temp Packaged Instantaneous Water Heater—
Two (2) years from the date of installation, but not longer than 27 months from the date of shipment.
Flo-Direct Gas Fired Water Heater—The stainless steel structure and stainless steel internals shall have a
5-year guarantee against failure caused by materials or workmanship provided by Armstrong. Provided only
clean potable water is heated.
Installation Date:
Installing Contractor:
Service Dates: