Armstrong FLO-RITE-TEMP 8120, FLO-RITE-TEMP 415, FLO-RITE-TEMP 415DW, FLO-RITE-TEMP 535DW, FLO-RITE-TEMP 665DW Installation And Adjustment Instructions

Bulletin No. AY-780-K

FLO-RITE-TEMP

INSTANTANEOUS WATER HEATER

INSTALLATION AND ADJUSTMENT INSTRUCTIONS

FOR SINGLE AND DOUBLE WALL UNITS

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.

FLO-RITE-TEMP

INSTANTANEOUS WATER HEATER

INSTALLATION AND ADJUSTMENT INSTRUCTIONS

NOTICE

No water heater will work satisfactorily if improperly installed and operated. These instructions contain
important information for the installation and adjustment of the FLO-RITE-TEMP Water Heaters. Read
these instructions carefully before installing this unit. FAILURE TO ADHERE TO THESE
INSTRUCTIONS COULD RESULT IN SERIOUS BODILY INJURY OR PROPERTY DAMAGE.

STEAM PIPING INSTALLATION OF A SINGLE UNIT

Single and Double Wall

Steam

In

Armstrong Pressure

Reducing Valve (If Req'd)

Armstrong

I.B. Trap

Armstrong Thermostatic

GP-2000

Air Vent

2-15 psig Steam

in the Shell

Vacuum Breaker

Pressure

Gauge

Gate

Valve

Safety Relief

Valve

Armstrong

I.B. Trap

NOTE: FLO-RITE TEMP is provided with (1) one Armstrong Steam Trap and Thermostatic
Air Vent (shaded). All other items shown not included.

Fig. 2-1

NOTE: units may be piped in parallel for larger capacity requirements. See Fig. 15-1 for an example of
parallel unit 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

(Refer to Fig. 2-1)

1. Install the FLO-RITE-TEMP with adequate room to allow for tube bundle removal when cleaning is

required. See Table 12-1 for specific dimensions.

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.

October 31, 2002 @ 3:15 pm

2

3. An Armstrong Y-strainer should be installed
before the pressure reducing valve to reduce the
chance of dirt fouling.

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 conditions exist. (1) If the maximum
steam pressure could exceed the minimum water
pressure in the tubes, or (2) The maximum steam
pressure could exceed 150 psig (the maximum
steam pressure rating of the shell).

IMPORTANT -Steam supply pipe size
coming to the heat exchanger should NOT be
smaller than the steam connection supplied on
the heater, otherwise steam flow could be
restricted. If a pressure reducing valve is used,

installation should be as close as possible to the
Flo-Rite-Temp. Downstream piping from the
Pressure Reducing Valve should be expanded
immediately after the PRV to accomodate the
expanded volume of steam.

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 the floor if preferred.

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 also be used for a PRV external control pipe
if a PRV is required.

WATER PIPING INSTALLATION

(Follow same plumbing for DW units)

D

A

C

E

B

C

B

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.

F

A

Fig. 3-1

2. Isolation valves and hose connections added to both the inlet and outlet water supplies will allow for
Clean-In-Place equipment to be utilized.

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

October 31, 2002 @ 3:15 pm

3

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.

Minimum line sizes to drain should be as
follows: model 415 = 3/4", model 535 = 1",
model 665 = 1-1/4", model 8120 = 2". Line

sizes smaller than these will not allow sufficient
flow for making high 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 the unit. (See Fig. 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 or oversized.

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
move approximately 10% of the maximum rated
gpm of the FLO-RITE-TEMP in the system with
enough head to overcome the head encountered in
the loop.

NOTE: A thermometer should be installed in

the outgoing loop to monitor system temperature

(Fig. 3-1E). A thermometer may also be

installed on the loop return to monitor
temperature drop through the loop or to help
troubleshoot the diverting valve (Fig. 3-1D). The
thermometer referred to in point #4 and Fig. 3-1B
should only be used to set the FLO-RITE-TEMP
and never used to monitor system temperature.

NOTE: Expansion tanks should be used in on/
off demand applications where there is a short
duration of time from high flow to no flow of
water, i.e., a shut off time of 10 seconds or less.
(See Fig. 3-1F)

OPTIONAL SAFETY EQUIPMENT

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 15-30 degrees above that of the FLO-RITE-TEMP
will help prevent any chance of overheated water reaching the faucets. (NOTE: Normally unit will fail closed
and either no water or only cold water will flow from the unit.)

Option #2 A 3-way blending valve with a set
point 10-30 degrees above that of the FLO-RITE­TEMP will help 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
maximum flow of the system).

October 31, 2002 @ 3:15 pm

Temperature

Relief Valve

Option #1

4

Loop or System

Thermometer

Hot Water from

Flo-Rite-Temp

3-Way

Thermostatic

Valve

Loop or System

Thermometer

To Flo-Rite-Temp

Cold Water Supply

Option 3A

Temperature

Switch

Hot Water from

Flo-Rite-Temp

Option 3B

Pressure Switch

Loop or System

Thermometer

To steam

shut-off valve

Option #3Option #2

Hot Water Supply From

Flo-Rite-Temp

To Steam

Shut-Off Valve

!

Cold Water Supply to

Flo-Rite-Temp

Option #3 A temperature switch installed well downstream 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 that of the FLO-RITE-TEMP will help prevent the chance of 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 #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 fails or drops rapidly on the Flo-Rite-Temp.

Unlike a 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 is below the set pressure. The GP-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 a sample line piped to the W-1 Pilot of

GP-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.

October 31, 2002 @ 3:15 pm

Option #4

5

IMPORTANT UNIT START-UP AND

SHUTDOWN PROCEDURES

Its important to remember that water
pressure must ALWAYS be greater than steam
pressure on the unit to avoid boiling the water
in the tubes of the heat exchanger. When
starting up a FLO-RITE-TEMP it is very
important that the water supply is turned on to
the unit before any steam is turned on. Once the
unit is up and running, the inlet water valve
should never be closed unless the steam is
turned off first. When shutting down a unit you
should always first shut off the steam and then
allow water to run through the unit until it has
cooled and completely condensed all remaining
steam in the heat exchanger before closing off

the supply water to the unit.

ADJUSTING PROCEDURES

All models of FLO-RITE-TEMP’s have two
settings 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: Once the

low and high flow adjustments have been made,
the unit generally need not be adjusted again
unless your operating conditions change or a
different set point is desired. A significant drop
in temperature output or capacity is an
indication of a bad diaphragm or that the tube
bundle needs to be cleaned. Do not readjust the
valve unless isolation of the unit from the
system and running water to drain produces
poor temperature control. If capacity is
minimal, check the diaphragm or clean the
bundle but do not readjust the control valve.

START-UP AND ADJUSTING

PROCEDURE FOR MODEL 415

1. Before turning on the steam to the FLO-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 the FLO-RITE-TEMP is closed (this is
the isolation valve downstream of port “B” of the
thermostatic diverting valve). (See Fig. 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
from the FLO-RITE-TEMP. (See Fig. 3-1B).
This process also primes the units lower
diaphragm area with water. Failure to do this

prior to initial adjustment can result in
inaccurate settings and poor results.

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: always make sure there is water
pressure on the unit before adding steam.
Failure to do this will cause severe
hammering of the unit and possible damage).

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, let the 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 (see Fig. 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

October 31, 2002 @ 3:15 pm

6

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 from 155 °F down to
140 °F.

(IMPORTANT - When making the low flow
adjustment the high flow adjustment shaft
SHOULD rotate with the low flow adjustment.
If it does not do so, you will have to turn it by
hand while making the low flow adjustment).

Allow the unit to stabilize to be sure that the unit
will remain at the desired set point. The low flow
is now adjusted and should not be readjusted.

10. To make the high flow adjustment, SLOWLY
increase 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 flow adjustment
while maintaining that flow.

11. Place a small screw driver or center punch
through the hole in the high flow adjustment stem
(see Fig. 7-1) and turn it in a clockwise direction.
This will 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 - When making the high flow
adjustment the low flow adjustment SHOULD
NOT rotate with the high flow adjustment. If it
does, you will have to hold it stationary while
making your high flow adjustment).

12. The unit is now adjusted.

(IMPORTANT - If for any reason you must
readjust the unit, you will first have to return
the high flow adjustment back to its full up
position as stated in point # 7).

START-UP AND ADJUSTING PROCEDURE

FOR MODEL 535EP, 665SEP and 8120

High Flow Adjustment (HFT)

"

Low Flow Adjustment (LFT)

"

Top Of Mixing Valve

Fig. 7-1

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 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.

October 31, 2002 @ 3:15 pm

7

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.

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.

(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).

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.

CAUTION

When putting a heavy load on the heat
exchanger, watch the steam pressure gauge. This
pressure should not be permitted to fall below 2
psig. If it does and severe water hammer
develops, reduce the load by closing some of the
faucets or shut the system down. When steam
pressure drops under heavy load and hammering
occurs, not enough steam is getting to the unit.
This can be a result of an undersized reducing
valve, lack of boiler capacity or restrictive steam
lines. Hammering can also be caused by a loss of
water pressure where the water pressure in the
unit falls below the pressure of steam. This
condition is usually caused by improper shutdown
of the unit or someone closing the inlet water
valve with the steam pressure still on the unit.

(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

October 31, 2002 @ 3:15 pm

8

FLO-RITE-TEMP

Recirculation System Piping and Operation

Because of its relatively small size and compact­ness, 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
different components designed to work together to
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.

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-RITE­TEMP. 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 recirculation
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 capsule, a
balancing/bypass line with globe valve is required.

This diverting recirculating system eliminates
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
introduced into the system is instantly controlled by
the FLO-RITE-TEMP feed forward mode of operation.

Recirculation

Pump

Capsule Balance

Line

Globe Valve

Loop or System

Thermometer

Unit Setting Thermometer

October 31, 2002 @ 3:15 pm

A

B

C

Bypass to drain

3-Way Thermostatic Capsule

Fig. 9-1

9

FLO-RITE-TEMP-Accumulation System

For peak load conditions or to avoid large intermittent steam demands

The FLO-RITE-TEMP water heater accumula­tion 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 con­trolled 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 the appropriate 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.

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.

October 31, 2002 @ 3:15 pm

Fig. 10-1

10

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
elements fail causing personal injury.

The solution is to use the Armstrong Flo-Rite­Temp tankless instantaneous feedforward water
heater in series with a self-contained fail safe thermo­static mixing valve.

How The System Works

The system, when piped as shown in the
drawing, will provide a safe, continuous and depend­able 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,

O

usually the lowest set point of 120

degrees is used).
The 120°F water can be piped to the Rada Z358
thermostatic mixing valve which will blend cold 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 tempera­ture 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 dis­tance from the heater.

Feedforward control in the water heater elimi­nates 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

October 31, 2002 @ 3:15 pm

Fig. 11-1

11

Single Wall and Double Wall Profile

L

g

g

g

g

g

g

g

g

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).

Fig. 12-1

Table 12-1. Dimensions & Weights

Dimensions Connections

415

535

665

8120

415DW

535DW

665DW

8120DW

ABC D EFGHJ K

in mm54

in mm67- 1/2

in mm82

in mm85

in mm76- 1/8

in mm77- 3/8

in mm90- 5/8

in mm79- 7/8

1372

1715

2083

2159

1934

1965

2302

2029

4-1/2

114

5-1/4

133

5-3/4

146

5-3/4

146

4-1/2

114

5-1/4

133

5-3/4

146

5-3/4

146

7-1/2

190

8-5/8

219

10-3/8

264

11-3/4

299

7-1/2

190

8-5/8

219

10-3/8

264

11-3/4

298

7

178

9

229

10-3/8

264

12

305

7

178

9

229

10-3/8

264

12

305

4-1/2

3-1/2 893-1/2 897

114

5-9/16

4

141

102

6-5/8

4-3/4

168

121

8-5/8

6-1/8

219

156

4-1/2

3-3/8 863-3/4 9510-1/2

114

5-9/16

4

141

102

6-5/8

4-3/4

168

121

8-5/8

6

219

152

4-1/2

114

5-1/2

140

8-7/8

225

4-1/4

108

5

127

8-3/4

222

178

7-7/8

200

9-1/4

235

9-1/2

241

267

11-1/2

292

11-3/4

298

12-5/8

321

127

152

7-1/2

203

127

152

7-1/2

203

5

6

190

8

5

6

191

8

6-1/4

159

7-1/2

191

8-3/4

222

9-1/2

241

6-7/8

175

8-1/8

206

9-3/4

248

11-5/8

295

M1 2 3

50

7-1/2

1270

62

1575

74

1880

74

1880

75

1905

75

1905

87

2210

75

1905

12-3/8

12-3/8

1" NPT 253/4" N PT 202" NPT 50lb

190

9

1-1/2" NPT 401" NPT 252-1/2" NPT 65lb

229

11

2" NPT 501-1/4" NPT 323" NPT 80lb

280

3" NPT 802" NPT 504" 150# AN SI

314

7-1/2

1" NPT 253/4" N PT 202" NPT 50lb

190

9

1-1/2" NPT 401" NPT 252-1/2" NPT 65lb

229

11

2" NPT 501-1/4" NPT 323" NPT 80lb

280

3" NPT 802" NPT 504" 150# AN SI

314

100

100

k

k

k

lb

k

k

k

k

lb

k

Wt.Model

133

60
235
107
358
162
585
265
199

90
270
122
444
201
665
302

Table 12-2 Materials

Body Valve Valve Seats Diaphragm

(415) 303 Stainless Steel

Single WallDouble Wall

Bronze

with Teflon Inserts

(535/665/8120) Brass (665/8120) Brass

(415DW) 303 SS with

(415DW/535DW)

Teflon Inse rts

535DW/665DW/8120DW

(665DW/8120DW)

Brass

Note: ** There is an open vent to atmosphere between the tube sheets to detect tube failure.

Table 12-3. Specifications

Application Steam Supply Pr essure Water Supply Pressure Maximum Water Pr essure Dr op

Steam to Water 2 - 15 psig (0.14 - 1.0 bar) 20 - 125 psig ( 1.4 - 8.5 bar) 10 psig (0.7 bar )

October 31, 2002 @ 3:15 pm

(415/535) 303

Stainless Steel

303 SS

Brass

Viton® GF

Reinforced with

®

Nomex

Fiber

12

Heat Exchanger

Shell

Carbon Steel

ASME "U"

Stamped

Heat Exchanger

Tubes

5/8" 16 BWG

Admirality Brass

5/8" Copper Inner

Tube 3/4" I.D.

Grooved Copper

Outer Tube

Tube

Sheets**

Brass

Steam Side

Steel/Water

Side Brass

Tube Bundle

End Cap

Brass

N/A

Table 13-1

4

5

5

2

5

2

5

5

3

3

4

2

5

5

3

3

4

FLO-RITE-TEMP

CAPACITIES AND STEAM LOADS

Standard

Inlet

Temp.

°F

40

5060140

*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.

Hot Water Capacities*

Set

Temp.

120

130

140

160

180

120

130

160

180

130

140

160

180

Steam Pressure

psig psig psig psig psig psig psig psig bar bar bar bar bar bar bar bar

°F

2 5 10 15 2 5 10 15 0.1

lb/hr lb/hr lb/hr lb/hr lb/hr lb/hr lb/hr lb/hr m

17 18 20 20 714767 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 14

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 83
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 10111257

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

7789486545623688 1.61.61.82.0220246282311415
14 16 18 20 1050 1178 1347 1487 3.2 3.6 4.1 4. 5 475 532 609 672 535
27 30 34 37 1942 2179 2492 2751 6.1 6.8 7.7 8. 4 878 985 1126 1243 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 69
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 14

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 14

13 14 16 17 626 679 752 81
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 55
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 8 9 10 469 527 604 669 1.6 1.8 2.0 2.3 212 238 273 302 415
15 17 19 21 1013 1139 1306 1445 3.4 3.8 4.3 4. 7 458 515 590 653 535
28 31 35 39 1874 2108 2417 2673 6.4 7.0 7.9 8. 8 847 953 1092 1208 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 82
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 14

15 16 17 19 60
32 34 38 40 1307 1421 1576 1708 7.3 7.7 3.6 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 53
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 10

7 8 9 10 451 509 585 649 1.6 1.8 2.0 2.3 204 230 264 293 415
16 18 20 22 976 1100 1265 1402 3.6 4.1 4.5 5.0 441 497 572 634 535
29 33 37 41 1805 2036 2341 2594 6.6 7.5 8.4 9. 3 816 920 1058 1172 665
59 67 80 90 3540 4020 4800 5400 13.4 15.2 18.1 20.4 1606 1823 2177 2449 8120

St eam Capacities

Steam Pressure

145 5680 6160 6760 7160 32.2 32.9 32. 9 32.9 2576 2794 3066 3248 8120

627 702 76

745 816 877 4.3 4.5 4.5 4.5 313 337 369 396 415

145 5740 6090 6580 7035 32.2 32.2 32. 2 32.2 2603 2762 2985 3191 8120

145 5080 5520 6120 6760 28.8 31.3 32. 2 32.2 2304 2504 2776 3066 8120

608 682 74

145 5110 5565 6090 6510 32.2 32.2 32. 2 32.2 2318 2524 2762 2953 8120

658 729 790 3.4 3.6 3.8 4.3 273 297 330 357 415

588 661 72

115 4250 4950 5200 5750 19.3 22.5 23. 6 26.1 1928 2245 2359 2608 8120

Inlet

Temp.

°C

4

10

16

Set

Temp.

°C

49

54

60

71

82

49

54

60

71

82

54

60

71

82

Hot Water Capacities* Steam Capacities

Steam Pressure Steam Pressure

0. 35 0.7 1 0. 14 0.35 0. 7 1

3

/h m3/h m3/h m3/h kg/hr kg/hr kg/hr kg/hr

2.7 3.0 3.4 3.6 292 316 349 377 415

2.0 2.3 2.5 2.7 259 283 317 346 415

2.9 3.2 3.6 3.8 283 307 340 367 415

2.3 2.5 2.7 3.0 250 275 308 336 415

4.1 4.3 4.5 4.5 288 312 344 372 415

2.3 2.5 2.9 3.2 241 266 299 327 415

Standard

Model

October 31, 2002 @ 3:15 pm

13

Table 14-1

Problem Causes S olutions

The steam is not turned on to the unit. Open steam valve to the unit.

Only cold water
comes out of the
unit.

O nl y warm water
comes out of the
unit.

Extreme hot water
comes out of the
unit.

No water comes
out of the unit.

The unit hammers
an d bang s during
operation.

The water tubes in the heat exchanger are
plugged.
The differential pressure sensing diaphragm
is ruptured.
The mixing valve is not properly adjusted. Adjust the unit according to the instructions.
The steam pressure is too low. Increase s team pressure (2 - 15 psig).
Air has accumulated in the shell of the heat
exchanger.
The flow is above the rated capacity of the
unit.
The tubes in the heat exchanger are scaled. Remove the 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.
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.
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.

The steam pressure has dropped or a
vacuum has formed.
The water pressure had dropped below that
of the steam pressure and steam is forming
inside of the water tubes.

TROUBLESHOOTING GUIDE

See Clean-In-Place operating instructions or remove
tube bundle and clean.

Replace the diaphragm.

Install a thermostatic air vent on the s hell.

Make sure unit is sized properly.

Check diverting valve for a stuck or failed thermal
capsule.

Open valve.

Make sure steam trap is working and properly installed.
Make sure shell is sloped to drain. Do not elevate
condensate if pressure is low.
Increase pressure and install vacuum breaker at shell
drain (Figure 1-1).

In s t all a pres s u re s witc h on wat e r in le t to s hut off
steam on a drop in water pressure.

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 split nut 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.

October 31, 2002 @ 3:15 pm

DISASSEMBLY

14

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)

Armstrong

Pressure Reducing Valve

System Isolation

Valve

Steam In

I.B.

(If Req'd.)

GP-2000

Steam Pressure

Gauge

Safety Relief

Valve

Bypass to

Drain for

Setting

Setting

Thermometer

Heated

Water

Supply Water

NOTE: NOTE:

NOTE: Depending on capacity requirements a parallel water heater installation may also require (2) two PRVs in

NOTE: NOTE:
parallel.
proper reducing valve application.proper reducing valve application.

proper reducing valve application.

proper reducing valve application.proper reducing valve application.

Single wall installation shown - Double wall would be similar. See your Armstrong Representative forSingle wall installation shown - Double wall would be similar. See your Armstrong Representative for

Single wall installation shown - Double wall would be similar. See your Armstrong Representative for

Single wall installation shown - Double wall would be similar. See your Armstrong Representative forSingle wall installation shown - Double wall would be similar. See your Armstrong Representative for

System

Isolation

Valve

Bypass

to Drain

for Setting

Setting

Thermometer

Thermal

Loops

Thermal

Loops

Vacuum
Breaker

2-15 Psig Steam

in The Shell

Armstrong

Trap

I.B.

Thermostatic

Air Vent

2-15 Psig Steam

in The Shell

I.B.

Armstrong

Trap

Steam

Pressure

Gauge

I.B.

Armstrong

Trap

October 31, 2002 @ 3:15 pm

Fig. 15-1

15

Clean-In-Place Operating Instructions

)

D

Temp’s — hot water capacity, temperature, or an increased

When there is a noticeable drop in the Flo-Rite-

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-Rite­Temp.
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

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.

Flo-Rite-Temp Clean-In-Place

35"

(889 mm)

Air Vent

Return

Hose

Air

ischarge

Hose

Drain

* RITE-QWIK is a non hazardous chemical cleaner which has

been proven effective for removing deposits without
harming the FLO-RITE-TEMP internally.

Armstrong-Yoshitake, Inc.

221 Armstrong Blvd., P.O. Box 408, Three Rivers, Michigan 49093 - USA Ph: [phone] Fax: [phone]

Bulletin No. AY-780-K 8/01 Printed in U.S.A.

Steam Traps \ Humidifiers \ Steam Coils \ Valves \ Air Vents \ Pumping Traps \ Water Heaters

www.armstrong-intl.com

47"

(1194 mm