31
P
ROPANE
G
AS
T
ANKS
AND
P
IPING
I
F
THE
GAS
FURNACE
IS
INSTALLED
IN
A
BASEMENT
,
AN
EXCAVATED
AREA
OR
A
CONFINED
SPACE
,
IT
IS
STRONGLY
RECOMMENDED
TO
CONTACT
A
PROPANE
SUPPLIER
TO
INSTALL
A
GAS
DETECTING
WARNING
DEVICE
IN
CASE
OF
A
GAS
LEAK
.
• S
INCE
PROPANE
GAS
IS
HEAVIER
THAN
AIR
,
ANY
LEAKING
AS
CAN
SETTLE
IN
ANY
LOW
AREAS
OR
CONFINED
SPACES
.
• P
ROPANE
GAS
ODORANT
MAY
FADE
,
MAKING
THE
GAS
U
NDETECTABLE
EXCEPT
FOR
WITH
A
WARNING
DEVICE
.
WARNING
A gas detecting warning system is the only reliable way to detect a
propane gas leak. Rust can reduce the level of odorant in propane
gas. Do not rely on your sense of smell. Contact a local propane
gas supplier about installing a gas detecting warning system. If
the presence of gas is suspected, follow the instructions on Page
4 of this manual.
All propane gas equipment must conform to the safety standards
of the National Board of Fire Underwriters, NBFU Manual 58.
For satisfactory operation, propane gas pressure must be 11 inch
w.c. at the furnace manifold with all gas appliances in operation.
Maintaining proper gas pressure depends on three main factors:
1. Vaporization rate, depending on temperature of the liquid,
and “wetted surface” area of the container or containers.
2. Proper pressure regulation. (Two-stage regulation is
recommended for both cost and efficiency).
3. Pressure drop in lines between regulators, and between
second stage regulator and the appliance. Pipe size will
depend on length of pipe run and total load of all appliances.
Complete information regarding tank sizing for vaporization, recom-
mended regulator settings, and pipe sizing is available from most regu-
lator manufacturers and propane gas suppliers.
Since propane gas will quickly dissolve white lead and most stan-
dard commercial compounds, special pipe dope must be used.
Shellac-based compounds resistant to the actions of liquefied
petroleum gases such as Gasolac
®
, Stalactic
®
, Clyde’s
®
or John
Crane
®
are satisfactory.
Refer to the following illustration for typical propane gas installa-
tions.
200 PSIG
Maximum
5 to 15 PSIG
(20 PSIG Max.)
Continuous
11" W.C.
Second Stage
Regulator
First Stage
Regulator
Propane Gas Installation (Typ.)
Sizing Between First and Second Stage Regulator*
Maximum Propane Capacities listed are based on 2 psig pressure drop at 10 psig setting.
Capacities in 1,000 BTU/hour.
Pipe or
Nominal Pipe Size
Tubing
Tubing Size, O.D. Type L
Schedule 40
Length,
3/8"
1/2"
5/8"
3/4"
7/8"
1/2"
3/4"
Feet
10
730
1,700
3,200
5,300
8,300
3,200
7,500
20
500
1,100
2,200
3,700
5,800
2,200
4,200
30
400
920
2,000
2,900
4,700
1,800
4,000
40
370
850
1,700
2,700
4,100
1,600
3,700
50
330
770
1,500
2,400
3,700
1,500
3,400
60
300
700
1,300
2,200
3,300
1,300
3,100
80
260
610
1,200
1,900
2,900
1,200
2,600
100
220
540
1,000
1,700
2,600
1,000
2,300
125
200
490
900
1,400
2,300
900
2,100
150
190
430
830
1,300
2,100
830
1,900
175
170
400
780
1,200
1,900
770
1,700
200
160
380
730
1,100
1,800
720
1,500
To convert to capacities at 15 psig settings - multiply by 1.130
To convert to capacities at 5 psig settings - multiply by 0.879
Propane Gas Piping Chart I
Sizing Between Single or Second Stage Regulator and Appliance*
Maximum Propane Capacities Listed are Based on 1/2" W.C. pressure drop at 11" W.C. setting.
Capacities in 1,000 BTU/hour.
Pipe or
Nominal Pipe Size
Tubing
Tubing Size, O.D. Type L
Schedule 40
Length,
3/8"
1/2"
5/8"
3/4"
7/8"
1-1/8"
1/2"
3/4"
1"
1-1/4" 1-1/2"
Feet
10
39
92
199
329
501
935
275
567
1,071
2,205
3,307
20
26
62
131
216
346
630
189
393
732
1,496
2,299
30
21
50
107
181
277
500
152
315
590
1,212
1,858
40
19
41
90
145
233
427
129
267
504
1,039
1,559
50
18
37
79
131
198
376
114
237
448
913
1,417
60
16
35
72
121
187
340
103
217
409
834
1,275
80
13
29
62
104
155
289
89
185
346
724
1,066
100
11
26
55
90
138
255
78
162
307
630
976
125
10
24
48
81
122
224
69
146
275
567
866
150
9
21
43
72
109
202
63
132
252
511
787
200
8
19
39
66
100
187
54
112
209
439
665
250
8
17
36
60
93
172
48
100
185
390
590
*Data in accordance with NFPA pamphlet NO. 54
Propane Gas Piping Chart II
XIII. CIRCULATING AIR & FILTERS
D
UCTWORK
- A
IR
F
LOW
N
EVER
ALLOW
THE
PRODUCTS
OF
COMBUSTION
,
INCLUDING
CARBON
M
ONOXIDE
,
TO
ENTER
THE
RETURN
DUCT
WORK
OR
CIRCULATION
A
IR
SUPPLY
.
WARNING
Duct systems and register sizes must be properly designed for the
CFM and external static pressure rating of the furnace. Design the
ductwork in accordance with the recommended methods of “Air Con-
ditioning Contractors of America” Manual D.
Install the duct system in accordance with Standards of the National
Board of Fire Underwriters for the Installation of Air Conditioning, Warm
Air Heating and Ventilating Systems. Pamphlets No. 90A and 90B.
A closed return duct system must be used, with the return duct con-
nected to the furnace.
NOTE:
Ductwork must never be attached to
the back of the furnace.
Flexible joints may be used for supply and
return connections to reduce noise transmission. To prevent the blower
from interfering with combustion air or draft when a central return is
used, a connecting duct must be installed between the unit and the
utility room wall. Never us a room, closet, or alcove as a return air
chamber.
When the furnace is used in connection with a cooling unit, the fur-
nace should be installed in parallel with or on the upstream side of the
cooling unit to avoid condensation in the heating element. With a par-
allel flow arrangement, the dampers or other means used to control
the flow of air must be adequate to prevent chilled air from entering the
furnace and, if manually operated, must be equipped with means to
prevent operation of either unit unless the damper is in the full heat or
cool position.
When the furnace is installed without a cooling coil, it is recommended
that a removable access panel be provided in the outlet air duct. This
opening shall be accessible when the furnace is installed and shall be
of such a size that the heat exchanger can be viewed for visual light
inspection or such that a sampling probe can be inserted into the air-
stream. The access panel must be made to prevent air leaks when
the furnace is in operation.
When the furnace is heating, the temperature of the return air entering
the furnace must be between 55°F and 100°F.
