Service Manual
30
PROPANE GAS TANKS AND PIPING
I
F
THE
GAS
FURNACE
IS
INSTALLED
IN
A
BASEMENT
,
AN
EXCAVATED
AREA
OR
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
GAS
CAN
SETTLE
IN
ANY
LOW
AREAS
OR
CONFINED
SPACES
.
P
ROPANE
GAS
ODORANT
MAY
FADE
,
MAKING
THE
GAS
UNDETECTABLE
EXCEPT
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 instruc-
tions listed in the Safety Precautions section of this manual.
All propane gas equipment must conform to the safety stan-
dards of the National Board of Fire Underwriters, NBFU Manual
58.
For satisfactory operation, propane gas pressure must be 10”
WC + .5” WC 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 be-
tween 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,
recommended regulator settings, and pipe sizing is available
from most regulator manufacturers and propane gas suppliers.
Use only pipe dope approved for both L.P. and natural gases.
Refer to the following illustration for typical propane gas instal-
lations and piping.
200 PSIG
Maximum
5 to 15 PSIG
(20 PSIG Max.)
Continuous
11" W.C.
Second Stage
Regulator
First Stage
Regulator
Propane Gas Installation (Typ.)
3/8" 1/2" 5/8" 3/4" 7/8" 1/2" 3/4"
10 730 1,700 3,200 5,300 8,300 3,200 7,500
20 500 1,100 220 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
Pipe or
Tubing
Length
Feet
Tubing Size, O.D. Type L
Nominal Pipe Size
Schedule 40
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.
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
3/8" 1/2" 5/8" 3/4" 7/8" 1/2" 3/4" 1" 1-1/4" 1-1/2"
10 39 92 199 329 501 275 567 1,071 2,205 3,307
20 26 62 131 216 346 189 393 732 1,496 2,299
30 21 50 107 181 277 152 315 590 1,212 1,858
40 19 41 90 145 233 129 267 504 1,039 1,559
50 18 37 79 131 198 114 237 448 913 1,417
60 16 35 72 1,211 187 103 217 409 834 1,275
80 13 29 62 104 155 89 185 346 724 1,066
100 11 26 55 90 138 78 162 307 630 976
125 10 24 48 81 122 69 146 275 567 866
150 9 21 43 72 109 63 132 252 511 787
200 8 19 39 66 100 54 112 209 439 665
250 8 17 36 60 93 48 100 185 390 590
Tubing Size, O.D. Type L
Nominal Pipe Size
Schedule 40
Pipe or
Tubing
Length
Feet
*Data in accordance with NFPA pamphlet No. 54
Sizing Between Second or Second Stage Regulator & 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.
Propane Gas Piping Chart II
Circulating Air & Filters
DUCT WORK - AIR FLOW
N
EVER
ALLOW
THE
PRODUCTS
OF
COMBUSTION
,
INCLUDING
CARBON
MONOXIDE
,
TO
ENTER
THE
RETURN
DUCT
WORK
OR
CIRCULATION
AIR
SUPPLY
.
WARNING
Duct systems and register sizes must be properly designed for
the CFM and external static pressure rating of the furnace. De-
sign the ductwork in accordance with the recommended meth-
ods of “Air Conditioning Contractors of America” Manual D.
Install the duct system in accordance with Standards of the Na-
tional Board of Fire Underwriters for the Installation of Air Con-
ditioning, Warm Air Heating and Ventilating Systems. Pamphlets
No. 90A and 90B.
OPERATION