Turbonics SelectTemp H-6 Owner's manual

j elccl aullw e 44 9 2
MODULATING ZONE HEATING
\
C
4001 PEARL ROAD
CLEVELAND, OHIO 44109
[phone] FAX: [phone]

APPLICATION,
INSTALLATION AND SERVICE MANUAL
for the
g
elecTrov
MODULATING ZONE HEATING SYSTEM
This manual has been compiled for the purpose of supplying the necessary
information for the application, installation and service of the Selec-
Temp heating system under normal conditions. Inquiries for additional in-
formation on unusual applications or special conditions should be directed
to:
TURBONICS, INC.
4001 PEARL ROAD
CLEVELAND. OHIO 44109
[phone] 
FAX: [phone]
Printed in U.S.A.

Form No. 2594H

LIST OF CONTENTS
SECTION

PAGE
I APPLICATION

1.
Determine Heat Loss 
2.
Select Unit Size

3.
Select Unit Location 
4.
Determine Boiler Size 
5. Select and Locate Boiler

6.
Select Type of Piping System

7.
Size Supply Pipe and Tubing 
8.
Size Return Pipe and Tubing

9.
Select Auxiliary Equipment

II INSTALLATION

16
10. Unit Wall Openings
 16
11. Unit Mounting 
18
12. Boiler Piping

18
13. Pressure Reducing Valve 
19
14. Condensate Return Pump 
19
15.
Supply and Return Mains 
21
16. Trap and Drip Main Connections

22
17.
Supply and Return Tubes 
23
18.
Soldered Connections

24
19. Insulation 
25
20.
Unit Connection 
25
21.
Dual Wall Group 
26
22.
Free Standing Frames 
26
23.
Summary of Installation Procedure 
27
III MAINTENANCE AND SERVICE

29
24.
General 
29
25. Design and Operation 
29
26.
Putting System in Service

30
27. Calibration of Thermostat 
30
28.
Steam Boiler Cleaning Procedure

31
29.
Water Treatment for Steam Boilers 
31
30.
Addition of Make-Up Water to Residential Boilers

31
31.
Check List for Unit Performance

32
32. Check List for Pressure Valve Performance

33
33. Check List for Condensate Pump

33
34.
Replacement of Needle, Bulb and Bellows in Units

34
35.
Replacement of Outboard Bearing Assembly

36
36.
SelecTemp Bearing Cleaning and Lubrication

38
37.
General Water Treatment Procedures for Steam Boilers

39
TABLES
NUMBER 
DESCRIPTION  PAGE
I 
Unit BTUH Output ((g. 65 ° Inlet Air) 
3
II 
Capacity of Copper Supply Tubing

10
DI Capacity of Horizontal or Down Flow Steam Supply Mains 
10
IV Steam Pressure Drop 
11
V  Capacity of Vertical Supply Risers

12
VI Capacity of Horizontal or Vertical Return Mains 
12
VII Expansion Loop for Copper Pipe 
14
3
3
3
3
3
4
9
12
12
Page 2

g
egt- l — efflp
SECTION I
APPLICATION
1.
DETERMINE HEAT LOSS
The heat loss for each room or individual area to
be heated should be accurately determined using the
methods shown in the American Society of Heating
and Refrigerating and Air-Conditioning Engineers
Guide or manuals of The Institute of Boiler and
Radiator Manufacturers or National Warm Air
Heating and Air Conditioning Association.
2.
SELECT UNIT SIZE
The sizing of the units for each room is based
on the room heat loss and steam pressure available
at the unit. Table I gives the capacity of the three
sizes of units at different pressures. On most sys-
tems a design pressure of 6 to 7 psi at the unit
should be used, although pressures up to 10 psi may
be used on applications where higher discharge air
velocities are not objectionable.
Where the heat loss of the room exceeds the ca-
pacity of the H-18 unit, two or more units may be
used. Extremely long and narrow or other odd-
shaped rooms may require more than one unit for
the best heat distribution. Unit capacity in excess
of the heat loss is not objectionable because the unit
automatically modulates to maintain the temper-
ature selected.
On residential or other applications where con-
stant temperatures are maintained throughout the
heating season, no pickup factor need be added. On
installations where lower temperatures may be
carried when the rooms or building are not in use,
a pickup allowance of about 25% should be added to
the heat loss and the units sized accordingly.
3.
SELECT UN IT LOCATION
The unit should be located on an outside wall or
close to an outside wall and as near to the floor as
practical. It should not, however, be located so
close to the floor that carpeting will interfere with
the removal of the grille. When located in a corner,
the unit should be mounted so the thermostat side is
at least four inches from the adjacent wall.
4. DETERMINE BOILER SIZE
The required output of the boiler is based on the
total heat loss from the building and not on the total
capacity of the individual units. An allowance for
heat loss from piping is not necessary on the aver-
age domestic installation, but on commercial and
industrial applications a piping allowance of about
5% should be added.
On installations where temperatures are main-
tained continuously, a pickup allowance need not be
added to the load. On applications such as churches
or public buildings, where low temperatures are
carried when the building is not in use but where
quick pickup is desired, a combined piping and pick-
up allowance of 30% should be added to the design
heat loss in sizing the boiler.
In small dwellings with one bath using an instan-
taneous hot water coil, the hot water load is not
added to the heating load in sizing the boiler. In
larger buildings, however, the load from either
storage type or tankless water heaters should be
considered in sizing the boiler. Methods for sizing
such hot water loads are found in the A.S. H.R.A. E.
Guide.
TABLE I
UNIT BTUH OUTPUT (f1 65° INLET AIR)
MODEL
STEAM PRESSURE 
AT UNIT 
- 
LBS. 
PER 
SQ. 
IN.
2
3
4
5 6
7
8
9
10
H-6
2,100 2.900
3.700
4.200
4,900
5.300
5,600
5.900
6,150
H-12
4,000
5.850
7.500 8,750
9.700
10.550 11,300 11,850 12,300
H-18 6.600
9,100 11,200
13.050 14.600
15,850
17.000 17.850 18.600
Page 3

CAUTION
MAKE ADEQUATE PROVISIONS
FOR EXPANSION OF PIPING
CONDENSATE RETURN TUBE
UNIT SUPPLY TUBE
PRESSURE REDUCING VALVE

STEAM SUPPLY MAIN
CONDENSATE RETURN MAIN
CONDENSATE PUMP
FLOAT
TRAP
Section I
APPLICATION
Sualz.tx
5.
LOCATE AND SELECT BOILER
The boiler may be located as desired, since
properly sized mains will carry the steam long
distances and still assure positive heat distribution.
The smoke pipe from the boiler to the chimney
should be kept as short as possible. Sufficient
space should also be allowed around the boiler for
access and service.
It is imperative that the boiler selected is of a
design that reliably delivers dry steam under adverse
operating conditions. Contact the factory for boiler
recommendations.
6. SELECT TYPE OF PIPING SYSTEM
The following types of piping systems should be
carefully studied to determine which is best suited
for the building in which the equipment will be
installed. The considerations in regard, to supply
lines are:
The pressure drop in the supply mains and
tubing must be low enough to give the desired
pressure at the unit.
The piping must be sized and pitched to permit
the flow of condensate in the supply lines with-
out objectionable noise.
The maximum vertical height of tubing takeoffs
must be limited to that where the steam pres-
sure in the main will lift the condensate through
the tubing, (about 2 feet per psi in the main).
Where steam and condensate are flowing in the
same direction, in pipes either vertical or on a
downward horizontal pitch, the pressure drop is the
controlling factor. Where steam and condensate are
flowing in the opposite direction, either in a vertical
riser or in a horizontal line with an upward pitch,
selecting pipe large enough to obtain quiet operation
is necessary. In tubing supply take -offs both the
pressure drop and the maximum vertical lift must
be considered, but the pitch is not a factor.
Locating supply piping underneath concrete slabs
is not recommended. The difficulties in providing a
proper pitch, suitable expansion joints and anchors,
waterproof insulation, and connections that are both
tight initially and undamaged during construction
all make this type of piping impractical for most
installations. When the steam supply must be lo-
cated below concrete floors, a suitable access
trench with removable cover should be used.
Return piping under slabs is also subject to many
of the same limitations. Insulation is seldom re-
quired and the lines are not under pressure; so
serious leaks are less likely. Maintaining proper
pitch in the piping while the floor is being poured,
on the other hand, is even more critical than for
the steam supply lines. For these reasons, return
piping under slabs without provisions for access
should be avoided if possible.
Steam supply piping in longer lengths is usually
pitched downward in the direction of steam flow (not
less than one inch in 40 feet) with a float trap at any
low point to drain the condensate. Supply piping
may also be pitched upward in the direction of steam
flow but larger pipe sizes are then required to per-
mit the condensate to drain back against the flow of
steam, as explained in Article 7.
Steam supply mains may be run with either iron
or type L copper pipe.
 The copper pipe with
Figure 1 - Perimeter Main System - Up-Feed to Units With Tubing Take-Offs
Page
4

CONDENSATE
RETURN TUBE
UNIT SUPPLY
TUBE
CONDENSATE
RETURN
MAIN
FLOAT TRAP
CONDENSATE
PUMP
UP FEED
SUPPLY MAIN
STEAM SUPPLY MAIN
C
efetl — e v
Section I
APPLICATION
le
Figure 2 - Perimeter Main System - Up-Feed to Units
With Pipe
soldered joints will be found more economical in
sizes up to two inches. Iron pipe will generally be
lower in Cost on mains larger than two inches or
those in which few or no tubing take -offs are made.
Care must be taken when using iron pipe to keep the
system free from cutting oil, pipe dope or metal
chips. Flushing iron pipe mains with a hot caustic
solution before the units and traps are connected is
desirable.
The return mains in all systems should provide a
downward pitch towards the condensate pump of not
less than one inch in twenty feet. Return mains may
be run with either type L copper or steel pipe, but
where a number of tubing connections are made,
soldered joints and copper pipe are recommended.
The general piping arrangements commonly used
are described below. Combinations of the different
methods of piping may, of course, also be employed
on any installation to best fit the particular building
layout and available space.
a. PERIMETER MAIN, UP-FEED TO UNITS
(Figure 1 and 2.) This system employs a
return main generally parallel to the supply.
In a single or two-story building this permits
short supply and return tubing connections be-
tween the mains and the units. In multi-story
buildings the same system may be used with
vertical pipe risers. The main may also be
run in two directions from the boiler with sep-
arate traps on the end of each branch.
b.
CENTRAL MAIN, UP-FEED TO UNITS (Fig-
ure 3.) This system may be used where units
are located on the floor above the main with
tubing runs not over 10 to 15 feet in length; or
in multi-story buildings with pipe run-outs
from the main to vertical supply risers.
c.
PERIMETER MAIN, DOWN-FEED TO UNITS
(Figure 5 and 6.) This system may be used
in single story construction where a main
under the first floor is not practical or in
multi-story construction where the use of a
number of large vertical risers would result
in high material cost. With this system one
large riser would be piped from the boiler to
the level of the horizontal main with
smaller
down-feed supply lines, either pipe or tubing,
from the main to the units.
Page 5

STEAM SUPPLY MAIN
PRESSURE REDUCING VALVE
CONDENSATE RETURN MAIN
FLOAT TRAP
CONDENSATE PUMP
CONDENSATE RETURN TUBE
UNIT SUPPLY TUBE
CAUTION
MAKE ADEQUATE PROVISIONS
FOR EXPANSION OF PIPING
UNIT
SUPPLY
TUBE
STEAM SUPPLY MAIN
CONDENSATE
RETURN TUBE
CAUTION
MAKE ADEQUATE PROVISIONS
FOR EXPANSION OF PIPING.
CONDENSATE PUMP
IF CONCRETE FLOOR IS
USED, RETURN MAIN
SHOULD BE INSTALLED
IN TROUGH WITH COVER
PLATE, AS SHOWN.
Section
I
APPLICATION
gee.cl i
am
Figure 3 - Central Main System - Up-Feed to Units With Tubing Take-Offs
Figure 4 - Central Main System - Down-Feed to Units With Tubing Take-Offs
Page 6

Figure 5 - Perimeter Main System - Down-Feed to Units With Tubing Take-Offs
:1 1
CI)
ED
co.
0
NOLLV
OI
lddY
FLOAT-TRAP
STEAM SUPPLY MAIN
CAUTION
MAKE ADEQUATE PROVISIONS
FOR EXPANSION OF PIPING
CONDENSATE PUMP
IF CONCRETE FLOOR IS
USED, RETURN MAIN
SHOULD BE INSTALLED
IN TROUGH WITH COVER
PLATE, AS SHOWN.

RETURN MAIN CONDENSATE
DOWN-FEED
SUPPLY MAIN
STEAM SUPPLY MAIN
CONDENSATE
RETURN TUBE
VENT
UNIT
SUPPLY
TUBE
.se
FLOAT
TRAP
4
CONDENSATE
PUMP
Section I
APPLICATION
getc1 -14 11/
Figure 6 - Perimeter Main System - Down-Feed to Units With Pipe
d. CENTRAL MAIN, DOWN-FEED TO UNITS
(Figure 4.) This system can be used with
tubing supply lines to outside walls only when
the building is very narrow, since otherwise
the tubing lengths will be excessive. Pipe
runouts from the main and vertical down-feed
supply pipes may be used on larger buildings.
e.
PERIMETER MAIN, COMBINATION UP-FEED
AND DOWN-FEED TO UNITS (Figure 7.)
This system can be used advantageously in
larger buildings where horizontal mains can
be installed on intermediate floors.
When adapting SelecTemp to an existing steam
system in smaller buildings a complete new piping
installation is usually desirable, but in larger
buildings some or all of the present piping may be
Page 8
utilized. On two-pipe systems the existing piping
will frequently be satisfactory providing the supply
pipes are properly insulated and both supply and
return piping is correctly pitched. If the existing
piping on a one-pipe system is used as a supply, the
large pipes may be expensive to insulate or result
in high stand-by losses. This piping, however, can
be readily adapted for return lines if new supply
piping is added. Y-type strainers should be used
in any supply main between steel pipe and copper
pipe or tubing. Return lines from SelecTemp units
cannot be connected directly into a vacuum return,
but the condensate from one or more units may be
piped as shown in Figure 8. A separate return
system from the SelecTemp units may also be
drained to a condensate pump discharging into the
vacuum return or into the boiler.

UNIT
SUPPLY
TUBE
CONDENSATE 
I
RETURN TUBE—el
4111
= CONDENSATE RETURN
s ir 
MAIN
It
It
It
)1
STEAM
SUPPLY MA IN
VENT
FLOAT TRAP
STEAM
SUPPLY MA IN
)1
(I
‘4.
FLOAT TRAP
FLOAT TRAP
4 71
CONDENSATE
PUMP
CONDENSATE RETURN MA IN
HOFFMAN
75A FLOAT-
TYPE AIR
VENT
RETURN
FLOAT TRAP
VACUUM RETURN
Section I
APPLICATION
Figure 7 - Perimeter Main System - Up-Feed and Down-Feed to Units
Figure 8 - Piping Details for Connections
to Existing Vacuum Return System
7. SIZE SUPPLY PIPE AND TUBING
The total allowable pressure drop in the system
is determined by the difference between the pres-
sure available at the boiler and that required at the
units. The pressure available at the boiler varies
between the cut-in and cut-out settings of the burn-
er pressure regulator. These settings may differ
somewhat with the size and type of burner, but a
cut-in pressure not over 9 psi should be used as a
normal design basis. The pressure required at the
units, as discussed in Article 2, will generally
be 6 to 7 psi. Therefore, the difference available
for pressure drop in the piping system will be about
2 psi, which is divided between the steam supply
main and tubing.
Table II shows the pressure drop through 3/8"
and 1/2" 0. D. copper tubing for various lengths
and steam flow rates. The tubing size selected
should generally give a pressure drop of not over
one psi at the steam flow required for the desired
unit output (not at the nominal capacity of the unit,
if greater than required for the load).
The allowable pressure drop in the supply main
is the remainder obtained by subtracting the tubing
drop from the total allowed for the system. If a
section of main is to be designed for a one psi
pressure drop and is the same diameter through
its entire length, Table III can be used to find the
capacity of various pipe sizes and lengths. The
capacities shown are for the same flow through the
complete length of the pipe. Where the unit sup-
Page 9

Section
I
APPLICATION
TABLE II
CAPACITY OF COPPER SUPPLY TUBING, MBTUH
7 PSI AVERAGE STEAM PRESSURE
PRESSURE
DROP,  PSI
3/8  IN. 
O.D.
 TUBING
1/2 
IN. 
O.D.  TUBING
LENGTH.
 FEET LENGTH.  FEET
5
10 15 20
10 15 20
0.50 8.7
5.9
4.7
4.0
17.0
14.5 12.8
0.75
13.1
8.7 6.8 5.8
22.0
18.2
16.2
1.00
16.8 11.1
8.7 7.3
26.0
22.0
19.0
1.25 20.0
13.0
10.5
8.8
27.5
24.5 21.5
1.50 23.0 17.7
15.0
10.0 32.0
27.5
24.0
TABLEIII
CAPACITY OF HORIZONTAL OR DOWN
FLOW STEAM SUPPLY MAINS
MBTUH for I PSI Pressure Drop
(Based on 7 PSI Average Steam Pressure)
PIPE
SIZE
LENGTH OF  PIPE 
(FEET)
20 30 40
50 60 70
80 90 100 120
3/4" 81
69 57 52 46 43 40
38 36 ----
1"
141 120 100 91
81 76 71 67 63
58
1-1/4" 322 276 228
208 186 173 161 153 144 131
1-1/2" 501 428 354 323 289 269 251 238 224 204
2" 1040 869 719 655 587
545 510 481 454 415
ply tubes are taken off along the main, however,
the amount of steam flowing in the pipe is reduced
in the portions farther from the boiler, and the
pressure drop is less than that with the full quantity
of steam flowing through the entire length. Under
these circumstances, the pressure drop can be
approximated by using an arbitrary effective length
instead of the actual length. Where the supply tubes
are taken off at fairly regular intervals and all of
the steam is used in the length of piping to be sized,
the effective length is half the actual length. For
example, with a load of 80 M Btuh, a main length of
100 feet, and supply tubes taken off regularly from
a perimeter main, the effective length would be
100/2 or 50 feet. Referring to Table III, for a 50
foot length, 91 thousand Btuh is the capacity of a 1"
pipe, so this size would be selected and the pres-
sure drop would be somewhat less than one psi.
Mains of more than one pipe size may be designed
for larger systems by dividing the main into two or
more sections and sizing each section separately.
Table IV can be used for finding the pressure drop
in these cases. This table is based on 100 feet of
pipe, and for other lengths the pressure drop will
be increased or decreased in direct proportion to
the length. For example, if the section were 75 feet
long the pressure would be 75/100 or 3/4 of that
shown for 100 feet, or if the section were 150 feet
long the pressure would be 150/100 or 1-1/2 times
that shown in Table IV.
Page 10
Estimating the effective length for mains where
all of the steam is used in the section being sized
is explained above. In sections of main where only
a portion of the steam is used, the effective length
is estimated in -a different manner. The effective
length in any section of main where the steam is
used from take-off's spaced more or less regularly
can be calculated from the relation: EFFECTIVE
LENGTH = ACTUAL LENGTH x AVERAGE FLOW/
MAXIMUM FLOW. For example, in a section 80
feet in length with a flow of 250 M Btuh entering and
150 M Btuh leaving, the average flow is
250 + 150
2
200 M Btuh and the effective length would be 80
(actual length) x 200 (avg. flow) = 64 feet. This
(max. flow)
value of length would then be used to determine the
pressure drop from Table IV. Using the above ex-
ample with an effective length of 64 feet and a max-
imum flow of 250 M BTUH, from Table IV, 1-1/2"
pipe will have 1.2 psi pressure drop per 100 feet
and 1.2 x 64/100 or 0.768 psi for conditions given.
The above methods are used for either vertical
or horizontal supply piping where the flow of both
steam and condensate forming in the main are in
the same direction. Where steam and condensate
flow in opposite directions, as in a vertical pipe
supply riser, or a runout pitched up in the direction
of steam flow, Table V is used to obtain the pipe
sizes. The pressure drop with the flow rates shown

10,000
9,000
8.000
7,000
6,000
5,000
4,000
3.000
2,000
1,000
900
800
700
600
500
400
300
200
100
90
80
70
60
50
40
30
20
10
POU
N
DS
PE
R
HOU
R
STE
AM
FLOW
g
etc1
.1- ",}P
Section
I
APPLICATION
in
this Table will be about one ounce per square
inch for each 100 feet of pipe length and can be dis-
regarded in most instances.
Pressure drop calculations for supply mains
pitched down in the direction of steam flow should
be based on the steam flow required for the calcu-
lated heat loss (plus pick-up, if applicable) rather
than the total maximum capacity of connected units.
Selection of pipe sizes from Table V, vertical
risers or horizontal runouts, on the other hand,
should be based on the maximum unit capacity at
the operating pressure.
TABLE IV
STEAM PRESSURE DROP
STEEL PIPE - AVERAGE PRESSURE 7 PSI
.2  .3 
.4 
.5 
.6 .7.8.91.0

2

3 
4

5
PRESSURE DROP
-
PSI PER 100 FT. PIPE
Page
1

Section
I
APPLICATION
g
etecrev
TABLE V
CAPACITY OF VERTICAL SUPPLY RISERS AND HORIZONTAL
RUNOUTS PITCHED UP IN THE DIRECTION OF STEAM FLOW
PIPE
SIZE
INCHES
CAPACITY. 
MBTUH
VERTICAL
RISER
HORIZONTAL RUNOUTS
1”/10* 
PITCH
4 –
/10'  PITCH
3/4 8
9.3
11.9
1
14
15.8
22.0
1.1/4
31
33.3
43.2
1-1/2
48
45.3
56.0
2
97
74.9
92.4
2-1/2
159
--
—
3
282
--
—
3.1/2 387 --
—
4
511
--
—
5 1050
--
—
6
1800
-- —
8
3750 -- —
10 7000
--
--
• Data from: ASHRAE Guide.
8. SIZE RETURN PIPE AND TUBING
Sizes for return mains are shown in Table VI.
The capacity in pounds of condensate per hour
should include not only the condensate from the
units but also the condensate occurring in the sup-
ply main during the initial startup of a cold system.
All of the latter will be discharged into the return
main through a trap or traps. Therefore the return
main at the point where the trap is connected must
be sized for that proportion of the total boiler ca-
pacity which will be handled by the trap plus any
accumulated flow from the upstream side of this
connection. The return main at the point where a
single trap drains a supply main should be sized
for a condensate flow of about 3/4 of the boiler
capacity.
TABLE VI
CAPACITY OF HORIZONTAL OR VERTICAL RETURN MAINS
(Horizontal
Mains Pitched Not Less Than I In. per 20 Ft.)
PIPE

SIZE
(NOM.  I.D.) 1/2
3/4 1
1-1/4 1-1/2
CAPACITY
LBS.
 PER HR.
100 250
500
1000 1500
1/4" O.D. tubing may be used for single unit short
condensate return tubes, while 3/8" O.D. tubing is
mandatory for runs longer than 5 feet. Larger tubing
may also be required where special piping provisions
must be made, as explained in the installation section.
Vertical pipe returns should be vented at the highest
point with a float type air vent of sufficient capacity.
(Hoffman 75A or equivalent) Horizontal return mains
longer than 100 feet may also be vented at the point
farthest from the condensate return pump. Maintain-
ing the minimum pitch of not less than one inch in 20
feet is extremely important in both return mains and
tubing. Although it is possible to use 1/2" conden-
sate return mains for low flows, it is preferable to
use 3/4" condensate returns for 3 units or more.
9. SELECT AUXILIARY EQUIPMENT
The final step in the application of a SelecTemp
system is to select the auxiliary equipment. The
common items used, some required and some
optional, are discussed below.
Figure 9 - Condensate Return Pump
a. CONDENSATE PUMP - A condensate return
pump having a capacity about double the aver-
age peak hourly condensate flow rate should be
selected. The pump must be located at a level
below the lowest point in the return system.
The pump receiver must be vented to the at-
mosphere and an overflow to a drain should be
provided. The pump overflow opening should
preferably be at a level below the lowest unit
in the system, otherwise water may be forced
out of the unit bearings in case of pump failure.
Condensate return pump capacities are given
at a specified discharge pressure; which in
operation will be the sum of the boiler oper-
ating pressure, the pressure required to lift
the water from the pump level to the water
line, the friction loss in the piping from pump
to boiler, and the pressure required to open
the check valve. The lift pressure is 1 psi for
each 28" of lift. The friction loss in the piping
per hundred feet at a 3 GPM rate can be esti-
mated at 0. 5 psi for 1" pipe and 2 psi for 3/4"
pipe. The pressure required to lift the check
valve will vary with the valve design, but will
generally be less than 1 psi. Condensate
pumps should not be used with discharge
pressures exceeding that for which they are
nominally rated.
Condensate Return Pumps with float switches
are available. The No. 203275 Pump has a ca-
pacity of 3 GPM against a head of 40 psi and is
suitable for use on loads up to 750,000 Btuh.
The No. 203295 Pump has a capacity of 5 GPM
Page 12

FEED WATER TANK GROUP-
INCLUDES TANK WITH
COVER. SUPPORT AND
WATER VALVE.
CP
ELECTRIC
MOTOR-DRIVEN
CONDENSATE PUMP
C
efeci7,1,
Section I
APPLICATION
against a head of 40 psi and may be used on
loads up to 1,500,000 Btuh.
The condensate pump motor on these models
starts and stops from a float switch which is
operated from the water level in the receiver.
Where automatic water feed is required, a
feed water tank group, Figure 10, is available.
These parts provide an open tank of about 12
gallons capacity, a solenoid valve between the
tank and pump receiver, and the necessary
tank supports for mounting. A combination low
water cut-off and pump control, a McDonnell-
Miller No. 42, is used to operate the solenoid
valve. This arrangement permits the treat-
ment of the make-up water and allows the op-
erator to observe the amount of water used by
the system.
Figure 10 - Feed Water Tank
The addition to the boiler of undetermined
amounts of untreated water may result in boiler
corrosion with resulting short life for the
equipment. For this reason, an a u t o m at i c feed
to the pump receiver without the tank is not
recommended.
Automatic water feeders connected directly
to the boiler should never be used on Selec-
Temp systems.
b.
PRESSURE REDUCING VALVE - Rapid vari-
ations of pressure at the Selectemp units is
undesirable. Therefore, on smaller boilers
particularly, where the burner cycles fre-
quently, a pressure reducing valve in the
supply main should be used. For mains up to
200,000 Btuh capacity and not over 15 psi inlet
pressure, a 1-1/4" regulator valve, Part
Number 203160, is available.
For larger mains or higher pressures, any of
the standard commercially available
steam
reducing valves may be used.
c. STEAM TRAPS - Condensate forming in the
steam supply mains must be removed by a
steam trap and not allowed to drain through
the units. A float type, non-thermostatic trap
is recommended for this purpose, such as the
Part No. 203300.  This 3/4" trap has
a discharge capacity of about 200 pounds of
water per hour under SelecTemp system oper-
ating conditions. During running periods, the
trap handles only the small amount of conden-
sate formed to offset the heat lost from the
pipe main. During start-up periods, however,
the trap handles the condensate required to
heat the main initially, with flow through the
trap at a much higher rate. The main trap
should, therefore, be selected to handle not
less than 75% of the full capacity of the boiler
on a single main, or the proportional part of
the boiler capacity on branch mains. Using the
3/4" trap, at least one trap for each 250,000
Btuh of boiler capacity would thus be required.
Traps of larger diameter and capacity are
available, but most SelecTemp piping systems
should not be designed to collect supply main
condensation at any one point at a rate in ex-
cess of the capacity of the 3/4" trap.
d. EXPANSION JOINTS - Supply and return mains
of copper or steel will expand and contract ap-
proximately 1/4" and
1/6"
respectively for
each ten feet of length. On mains where tubing
take-offs are made, this expansion or con-
traction should be limited to no more than 1"
of movement at any one point to prevent ex-
cessive stress on the supply and return tubes.
Therefore, on such straight mains over 40 feet
in length, provisions must be made to control
the expansion. Table VII shows a common type
of expansion joint and the necessary design
data for copper pipe. The same dimensions
can also be used for steel pipe.
Where this type of expansion joint is used,
the added length for pipe and fittings should be
included in the equivalent length when calcu-
lating pressure drop.
Commercially available expansion joints,
such as those manufactured by the Flexonics
Corp., Maywood, Illinois, may be necessary
on some installations where space limitations
prevent the use of the U-type joint. When any
expansion joint is used, the main must be
firmly anchored so that maximum movement
will occur at the joint.
Page 13

STEAM SUPPLY MA IN
PRESSURE REDUCING
VALVE
GATE VALVE
STEAM SEPARATOR
STEAM SEPARATOR DATA
MODEL
RATING DIAMETER
INLET
OUTLET
DRIP
203351 250,000 BTU 6 IN  . 3  IN, 1.1/4  IN. 2 IN.
203364 500,000
BTU 8 IN. 2  IN.
2  IN. 3
IN.
Section I
APPLICATION
C
etecTu l p
TABLE VII
EXPANSION LOOP FOR COPPER PIPE*
DIMENSION "R" - INCHES
INCHES OF
EXPANSION
NOMINAL  PIPE
 SIZE
3/4
1 1-1/4
1-1/2
2
2-1/2
3
1
15
17 19
20
23 26
28
2 21
24 26
28 32
36
39
3
26
29 32 35 40
44 48
*Data from American Brass Co. Bulletin AlA File No. 29-B-41
e. STEAM SEPARATORS - A minimum amount of
water flowing through the SelecTemp units and
piping is desirable for best operation of the
system. Water carry-over from the boiler
into the steam main is particularly detrimental
to the proper functioning of units, traps, and
condensate pump. Most small boilers, below
30 BHP, will tend to carry over considerable
water; so that some means of draining off this
water before it goes out through the main is
necessary. This may be accomplished by pro-
viding a steam separator at the boiler. Figure
11 shows typical piping connections and the ca-
pacities and dimensions of separators avail-
able from the factory. Where the load exceeds
the capacity of one separator or where dual
Figure 11 - Steam Separator
Page 14
outlets are used from the boiler, two separa-
tors may be used. In some installations, to
obtain other sizes or numbers of outlet and
inlet tappings, a similar separator can best
be fabricated on the job.
f. SUPPLY PIPE AND TUBING INSULATION - All
supply mains and vertical pipe supply risers
must be insulated. Where steam pressure is
maintained most of the time on the SelecTemp
system, the heat loss from uninsulated supply
piping is greater than in "on-off' types of
heating. Uninsulated mains in basements or
other space should not be expected to heat
these areas, since no control of the heat is
available and during mild weather the wasted
heat will appreciably increase fuel consump-
tion. Supply tubing should be insulated in runs
through unheated spaces, in walls, or in any
cases where the run is longer than 6 feet.
Return mains and tubing do not require insu-
lation unless exposed to freezing temperatures.
For steel or copper pipe, preformed glass
fibre insulation of 1" thickness should be used
because of the superior insulating properties
as compared with 4 ply air cell, 1" thick 85%
magnesia, or 1/2" thick glass fiber. The ma-
terial is distributed and stocked nationally
under several trade names, a few of which are
listed below:
Owens-Corning "Fibreglas" Corp.
Nicholas Building
Toledo, Ohio
Trade Name - "Fibreglas"
Gustin-Bacon Mfg. Co.
210 W. 10th Street
Kansas City, Missouri
Trade Name - "Snap on Pipe Insulation"
Baldwin-Hill Company
1705 Breunig Avenue
Trenton 2, New Jersey
Trade Name - "Mono-Kover"
Procedures for installing insulation are given
in section II, Page 25.

g
egel —
eV
Section
I
APPLICATION
g. DUAL WALL ADAPTER GROUP - Parts
groups are available to permit supplying heat
through a common wall to two adjacent rooms
with a single H - 12 or H - 18 SelecTemp unit. A
manual damper arrangement permits adjust-
ment to supply to the second room up to 50% of
the heat output through a short duct and a grill.
This application provides thermostatic control,
of course, in only the room where the unit is
mounted, but where this factor or the open
duct connection between two rooms is not
objectionable the cost of the installation is
reduced.
Figure 12 -
Dual Wall Adapter Parts
The dual wall adapter parts are illustrated
in Figure 12. The H-12 dual wall group may be
used also with the II-18 unit if not more than
6,000 Btuh is required from the back side of
the unit.
Figure 13 - SelecTemp Unit Installed
in Free-Standing Frame
h.
FREE STANDING FRAMES - These adapters
provide a metal frame, 5" in depth and about
1/2" larger than the unit in length and width.
The bottom of the frame is open as shown in
Figure 13.
The frame can be used to mount a unit on a
masonry or other wall where the recessed unit
mounting is not feasible. The frame can also
be used on installations where the wall studs
are less than 3-5/8" and the unit can be only
partially recessed into the wall.
The 5" depth on the frame is sufficient to
permit running supply and return tubing inside
the frame and across the back of the unit.
Holes are provided in the left side of the frame
for the usual passage of the supply and return
tubing. The tubing can also be run up inside
the frame from the bottom.
Figure 14
-
Grille Locking Clamp
i. GRILLE LOCKING CLAMP-To prevent tam-
pering with or damage to units installed in
dormitories, hotels, or other public buildings,
a grille locking clamp is available. This clamp
illustrated in Figure 14, can be used with any
standard Selec Temp unit. A Phillips head
screw driver is required for removal of the
grille equipped with the clamp.
Page 15

STUD
UNIT
ALTERNATE METHOD OF USING
STRIPS AROUND FRAME
3/4" 
(LATH
& PLASTER)
5/8"
5/8" X 3/4" WOOD
g
eeetTety
SECTION II
INSTALLATION
10. UNIT WALL OPENINGS
a. NEW CONSTRUCTION - For framed walls, a
header and ve rtic al side support member should
be provided as shown in Figure 17. The dimen-
sions shown are slightly greaterthan the actual
outside measurements of the unit cabinet to allow
clearance for mounting.
If units are to be recessed in solid masonry
walls, wooden frames with dimensions as shown
in Figure 17 may be pre-fabricated and set into
the wall, or the free standing metal frame
Figure 13 may be used in the same manner.
Where units are not recessed, the free standing
frame may be fastened directly to the wall
surface.
MODEL
H-6
H-12 H-18
DIM.
C
6.3/4"
11"
..
15-1/2"
STUDS
HEADER
DIM. H-6
H-12
H-18
A 9
s16
13 5 ', 17 ' 4 4,
B _ 6
7 'n 10' 1
12 14%
DRILL (2) 3/4" MIN.
DIA. HOLES FOR
SUPPLY AND RETURN
TUBES,OR ONE
2" DIA. HOLE
-\
5-1/2
INSTALL UNIT
ABOVE
BASEBOARD
Figure 18 - Unit Dimensional Drawing
Metal plaster stop frames for lath and plaster
walls are available with dimensions as shown
in Figure 16. These frames insure a substantial
finished edge to the wall opening. After the
plastering has been completed, the unit is
mounted in the framed opening using the wood
screws which are provided with the unit.
Figure 17 - Details for Mounting Unit
in Wall on New Construction
b. OLD CONSTRUCTION - Framed walls with lath
and plaster or dry wall should be sounded in
order to locate the stud nearest the desired unit
location. An opening should then be made in the
wall on the left hand side of the stud in order to
determine its exact location. The unit opening
should then be marked on the wall, using the
left side of the stud for the right hand side of
the unit opening. The dimensions for these
openings are shown in Figure 19. Since the cabi-
net of an H-18 unit is slightly wider than the
distance between studs located on 16" centers,
the left hand stud will have to be notched about
1/2" when making an opening for an H-18 unit.
Page 16

1H ATTACH UNIT TO
I  STUD
WITH WOOD
SCREWS. IF LOCA.
1 
TION PERMITS
1
ATTACH UNIT
TO
PLASTER BOARD
WALL WITH 'MOLLY'
SCREW ANCHORS OR
USE METHOD SHOWN
IN FIGURE 20
CUT (2) 3/4 IN. DIA. HOLES
OR (1) 2 IN. DIA. HOLE FOR
TUBES AND SEAL WITH INSULA.
TION
CABINET
MOUNTING
FLANGE
GRILLE
LATH
BOARDS
PLASTER
I  U 2•
BOARD
UNIT
CABINET
FASTEN BOARD
TO WALL WITH
FLAT HEAD
SCREWS BE-
FORE ATTACH-
ING UNIT
WOOD
SCREWS
BASEBOARD
Section II
INSTALLATION
S
' eregt7e4sw
Openings are marked and cut in older framed
walls finished with wood lath and plaster in the
same manner as described above. However, the
wall on the left side of the opening for the H-6
and H-12 units must be reinforced by using
flat-head wood screws to fasten a 1" x 2" x 20"
wood strip along the inside edge of the opening
as shown in Figure 20.
and the tubes cannot be exposed, metal pipes or
waterproof cardboard tubes can be located in
the openings in the block to provide channels
for the tubes. If this method is followed, the
space around the supply tube must be large
enough to provide room for insulation. Pipe
sleeves must also be provided at any point
where the tubes pass through slab floors or
other masonry partitions.
Figure 19 - Details for Mounting Unit
in Wall on Old Construction
If units are to be recessed in masonry walls,
the proper size opening should be marked and
then cut with either a hammer and chisel or
skill saw equipped with a carborundum blade.
Normally it is much cheaper and simpler to
mount the units in metal free standing frames
as described in Article 22 unless the inside
wall is finished with furring strips and lath or
plaster or some other type of wall board. If
this is the case, the proper size opening should
be made and the unit fastened to plaster or wall
board with molly screws or their equivalent.
c. TUBE OPENINGS - For new, framed construc-
tion two 3/4" diam. holes or one 2" diam. hole
should be drilled in the left hand stud as shown
in Figure 17. If the tubes approach from under-
neath, similar holes would have to be drilled in
the floor plate but as far to the left as possible
in the adjoining stud space so a sharp bend
would not be made in the tubes. If the supply
tube approaches from overhead or other stud
spaces, one 3/4" diam. hole is required in each
stud, header, or plates through which the tube
must pass. A second 3/4" diam. hole is needed
in the floor plate for the return tube which must
pitch downward.
On new installations using masonry walls the
tubes can be run in furred spaces if available.
If the units are to be mounted in or on the walls
Figure 20 - Method of Attaching Unit
to Wood Lath and Plaster-Type Walls
On framed walls in existing buildings the
supply tube can be dropped down through the
stud space if it approaches from overhead.
However, the return tube will always approach
from below and in many cases the supply tube
will too. This means the floor plate must be
drilled near the left hand stud member and the
tubes pushed through. Sufficient space is pro-
vided between the cabinet and the left hand stud
on the H-6 and H-12 units although the use of a
tube bender to make a 90° bend at the point
where the tubes enter the unit is desirable. A
proper bend is mandatory on the H-18 unit
where the stud has to be notched an additional
1/2" over that required for the unit in order to
provide clearance for the tubes.
If free standing frames are fastened directly
to the wall and the tubes approach from the
bottom, they should run up inside the frame in
the space between it and the unit. Clearance is
also provided between the back of the unit and
back of the frame if the tubes approach from
the right.
If the units are recessed in solid masonry
walls or masonry walls which are furred out, a
pipe Chase will have to be provided between the
face of the wall and the tube opening in the unit
cabinet unless the tubes have been previously
located inside the wall.
Page 17

PRESSURE
REDUCING VALVE
TURN ADJUSTING SCREW
COUNTER -CLOCKWISE TO
DECREASE PRESSURE
Method of
Adjusting Valve
(Bottom View)
•
TURN ADJUSTING SCREW CLOCKWISE
TO INCREASE PRESSURE
I/6 IN. PIPE
TAPPING FOR
PRESSURE GAUGE
GATE VALVE
ADJUSTING SCRE
SUPPLY
MAIN
I/8 IN. I. P. TAPPING
FOR PRESSURE GAUGE
REMOVE PILOT VALVE
& BELLOWS ASSEMBLY
BEFORE SOLDERING
CLOSE TO VALVE
RISER MUST BE
SANE SIZE AS
BOILER TAPPING
REDUCING ELL
TO 1.1/4 IN.
Mounting Details
I
NO.203170
OR NO.203150
REPLACEMENT
GROUP -
INCLUDES
ALL PARTS IN
SHADED AREA
NO. 203118
ADJUSTING
SPRING
Cross Section
of
Valve
g
egel — ev
Section
II
INSTALLATION
11. UNIT MOUNTING
On either new construction or remodeling, the
units should not be installed until all other work
has been completed. Otherwise they are subjected
to all types of dirt and unnecessary abuse. If tem-
porary heat is required, and other methods are
not available or approved, a small number of
SelecTemp units should be rotated from room to
room as needed. When the work is completed these
units should then be carefully cleaned and checked
before permanent installation is made.
The left hand, right hand and top flange of any
Selec Temp unit each contains two holes through
which wood screws or other type fasteners may
be inserted when fastening the unit to the wall or
frame. Thus a total of six possible fastening lo-
cations are provided, although to securely mount
a unit only four of the openings need to be used.
For wood-framed openings on new construction
the right hand, left hand and top flange of all units
may be fastened directly to the frame with wood
screws which are provided.
The right hand flange of all units may also be
fastened in the same manner when installed in
framed walls on existing buildings. In cases where
one or more of the three flanges must be fastened
to lath and plaster, dry wall or other panels which
are not backed up by wood framing, molly screw
anchors or equivalent fasteners should be used.
After the mounting holes have been located,
which is easily done by sliding the unit into the
prepared opening and using a pencil to mark the
wall through the opening in the flanges, a pilot
opening for wood screws should be drilled through
the plaster or wall board into the wood frame. if
molly anchors are used, the same procedure is
followed except that a proper size opening for the
expansion screw must be drilled through the wall.
Sheet metal screws may be used to fasten the
units to the free standing metal frames.
12. BOILER PIPING
Iron Fireman steel boilers in the smaller sizes
will produce a satisfactory quality of dry steam
under most operating conditions. This permits
simple piping connections at the boiler as shown in
Figure 21. A riser of the same size as the boiler
outlet tapping should be run to the desired height of
the supply main. A reducing elbow should be used
at the top of this riser, with the inlet the same size
as the riser and the outlet the same size as the
main or the reducing valve, if used. A gate valve
should be connected ahead of the reducing valve.
Gate valves may also be used at the boiler on
branch mains.
The piping at the boiler must permit the water
condensing in the main to drain either back into the
boiler or out through the supply main. Condensate
will not drain back through a reducing valve; so re-
ducing fittings used on horizontal runs on the outlet
side of the valve must be of the eccentric type to
permit condensate flow in the same direction as the
steam flow. The boiler piping also should not be
designed to drain condensate back into the boiler
through the steam outlet if the outlet is smaller than
the sizes shown for vertical risers in Table V,
page 10.
Figure 21 - Boiler Steam Piping With Reducing Valve
Page 18

BOILER
ATER LEVEL
Section II
INSTALLATION
gleeel — e",P
The return line from the condensate pump
should be connected to a boiler tapping at least 2"
below the minimum water line on Iron Fireman
boilers. On boilers equipped with steam separa-
tors the same connection can be made if such a
tapping is provided on the boiler. If not, it should
be connected into a T which is located in the drip
line from the separator at least 2" below the min-
imum water level. The boiler water feed lines are
also connected at the same points.
Figure 22 - Piping Arrangement on Larger Boilers
On larger boilers or those not equipped with
steam separators, the piping at the boiler should
be installed as shown in Figure 22. The riser from
the boiler should be as large as the boiler tapping,
and the horizontal section of the equalizer pipe
should be not smaller than:
1-1/2" up to

80,000 BTUH Output
2" up to 150,000 BTUH Output
2-1/2" up to 200,000 BTUH Output
3"
up to 400,000 BTUH Output
4"
up to 800,000 BTUH Output
6" 
up to 2,000,000 BTUH Output
The T for connection to the main should
be taken
off vertically as shown and at a point several inches
from either the riser from the boiler or the equalizer
line to the return. The vertical return section of the
equalizer line should be not smaller than:
1-1/4" up to 200,000 BTUH Output
1-1/2" up to 300,000 BTUH Output
2" up to 800,000 BTUH Output
2-1/2" up to 1,200,000 BTUH Output
3,! up to 2,000,000 BTUH Output
The piping below the T in the vertical equalizer
line would be sized to fit the boiler return tapping.
13.
PRESSURE REDUCING VALVE NO.203160
The valve should be installed in a horizontal position
as shown in Figure 21. Care mustbe taken touse pipe
joint compound sparingly only on male threads. A
1-1/4" gate valve should be installed ahead of the valve .
If the main is larger or smaller than 1-1/4", a reducing
coupling from 1-1/4" to the desired main size should
be used. A pipe union should be provided near the
valve.
The valves are tested and set at the factory for a
discharge pressure of approximately 5 lbs. , but this
setting can be increased to a maximum of
10 lbs. To
increase the pressure one pound, turn the adjusting
screw 1-1/2 turns clockwise. Ten pounds pressure
would be reached by turning the adjusting screw clock-
wise approximately 7-1/2 turns. A 1/4 inch tapping
is provided on the outlet side of the valve for install-
ing a pressure gage to check the discharge pressure.
This is a pilot type valve with a water-cushioned
opening of the main bellows. Therefore, when the
valve is first put into operation an irregular regu-
lating characteristic can be expected for about 30
minutes while the water chamber is filling with
condensate.
The same general piping procedure should be fol-
lowed where other types of pressure reducing valves
are used.
14.
CONDENSATE RETURN PUMP
a. RETURN PIPING - The condensate return
main is connected into the opening provided
on the side of the condensate pump receiver.
The line should be pitched toward the pump
with a union provided close to the receiver.
b. VENT LINE AND OVERFLOW - A full size
pipe nipple and tee should be connected into
the vent connection on the side of the receiver
which is slightly lower than the condensate
inlet. The side of the tee should point up
with a short length of pipe threaded into it
and a "U" type fitting threaded on to the top
of this pipe. An overflow pipe, which can be
reduced to 3/8" or 1/2" O.D. tubing, should
be run from the end of the tee to a drain be-
low the level of the opening in the side of
the receiver. (See Figures 23A and 23B)
c. DISCHARGE PIPING - The pipe and fittings
between the pump and the boiler should be
the same pipe size as the pump discharge
opening. A good grade of horizontal swing
check valve should be in the discharge line
Page 19