15
Gas Piping Connections
T
O
AVOID
POSSIBLE
UNSATISFACTORY
OPERATION
PMENT
,
USE
THE
PROPER
SIZE
OF
NATURAL
/
PROPANE
GAS
PIPING
NEEDED
WHEN
RUNNING
PIPE
FROM
THE
METER
/
TANK
TO
THE
FURNACE
.
OR
EQUIPMENT
DAMAGE
DUE
TO
UNDERFIRING
OF
EQUI
WARNING
When sizing gas line, be sure to include all appliances which
will operate simultaneously.
The gas piping supplying the furnace must be properly sized
based on the gas flow required, specific gravity of the gas,
and length of the run. The gas line installation must comply
with local codes, or in their absence, with the latest edition of
the National Fuel Gas Code, NFPA 54/ANSI Z223.1.
Natural Gas Capacity of Pipe
In Cubic Feet of Gas Per Hour (CFH)
Length of
Nominal Black Pipe Size
Pipe in Feet
1/2"
3/4"
1"
1 1/4"
1 1/2"
10
132
278
520
1050
1600
20
92
190
350
730
1100
30
73
152
285
590
980
40
63
130
245
500
760
50
56
115
215
440
670
60
50
105
195
400
610
70
46
96
180
370
560
80
43
90
170
350
530
90
40
84
160
320
490
100
38
79
150
305
460
(Pressure 0.5 psig or less and pressure drop of 0.3" W.C.; Based on
0.60 Specific Gravity Gas)
CFH = BTUH Furnace Input
Heating Value of Gas (BTU/Cubic Foot)
To connect the furnace to the building’s gas piping, the install-
er must supply a ground joint union, drip leg, manual shutoff
valve, and line and fittings to connect to gas valve. In some
cases, the installer may also need to supply a transition piece
from 1/2” pipe to a larger pipe size.
The following stipulations apply when connecting gas piping.
•
Use black iron or steel pipe and fittings for the building
piping.
•
Use pipe joint compound on male threads only. Pipe
joint compound must be resistant to the action of the
fuel used.
•
Use ground joint unions.
OF
F
O
N
W
R
G
C
+
1
2
3
4
1
2
3
4
LOW
ER
SLOT
SI
DE
+
+
R
1
R12
4
R12
7
R12
8
R12
9
R13
5
R3
3
R1
R34 R63
4
R7
9
R8
8
R9
7
R10
4
R10
5
R19
8
R20
1
R7
0
R7
2
R55
R65
R4
0
R30
R7
R64
R
3
1
O
R4
N
1
R
5
1
R6
0
R1
84
R
18
2
R5
3
R
45
R6
1
R5
R5
4
R183
OFF
R1 85
R56
R44
R4
7
R18
7
R18
6
R 42
R16
6
R21
2
R9
2
R14
5
R8
9
R9
3
R18
1
R7
6
R7
5
R8
0
R179
R178
R4
9
R4
3
R18
0
R2
2
R5
2
R1
5
R
1
3
R2
8
R1
46
R155
R2
1
R1
2
R1
3
1
R2
3
R1
9
R
4
R
3
R2
0
R1
1
R1
8
R
1
0
R12
0
R14
7
R152
R169
R 1 3 0
R11
0
R113
R121 R115 R126
R125 R123
R11
2
R11
1
R15
1
R13
7
R13
6
R14
4
R
8
R1 93
R150
R168 R170 R149
R148
R4
6
R21
7
E3
7
1
E2
2
E2
8
K
2
K1
0
K
8
K
6
K
7
1
U
1
DS
1
O FF
O N
SW
1
O FF
O N
SW
2
1
2
4
SW
3
CR2
9
CR3
0
CR1
7
2
0
CR1
CR1
3
CR
7
CR
3
CR3
5
CR1
8
CR2
6
CR3
4
CR
2
1
Q1
0
Q1
4
Q
6
CR
1
CR
6
CR1
6
CR2
0
CR2
2
R134 R216
CR28
R133
CR
3
1
R2
CR
23
1
Q
5
Q
3
Q
2
CR19
Q16
Q
9
Q
7
R117 R118 R119
Q8
CR2
4
Q1
1
R16
1
CR32
R162
R160 R163
K9
R157
R16
7
R101
R210
R10
2
R1 03
R8
6
R
85
R32
R 69
R 39
R2
7
CR
4
R19
9
R 91
R8
1
R
6
R15
9
R20
0
R10
9
R20
9
R100
R
96
R14
3
R20
7
R213
R215
CR1R1
96 1
C
R
1
0
R57
R7
R35 1
R48
R9
4
R6
2
R2
9
R98
R173
R12
2
R139
CR27
CR4
R19
5
R82 R1
7
C1
9
C21
R158
C2
3
C1
4
C3
7
C3
8
R50
C3
6
R164
R172
C31
CR9
3
C
3
C2
7
C
18
C33
R132
C2
0
C
1
6
C2
4
C
1
7
C4
4
C1
5
C1
3
C1
1
C1
0
C22
CR25
Q12
R9
C4
C
1
C
2
Q4 R177
R176 C28
CR
33
R95 R171
Q13
R1
38
Q
1
C3
5
C3
4
C3
2
C4
3
C42
K4
C41
K3
K1
C40
C3
0
R11
6 R10
C1
7
2
CR5
D H U M
CR2
Y1
Y/ Y2
R59 R16 R87 R78 CR8
CR 39
FLAME
CURRENT
1VDC=1UA
CR38
R25
R24
R2
6
R37
R36
R3
8
R6
6
R6
7
R6
8
R8
3
R9
0
R9
9
R10
8
R154
R156
R19
7
R14
2
R14
1
R20
2
R20
3
R20
4
R20
5
R20
6
R21
1
R10
6
6
CR14
1
E2
4
W
1
W
2
TP
5
TP
6
TVS1
R58
F
1
C2
6
E3
2
E2
5
E
2
E
1
E
3
E2
9
RV
2
U
5
U
4
U
3
U
2
CR3
6
CR3
7
Q1
8
Q1
9
C2
5
R15
3
R1
40 R11
C4
R
4
E4
2
59-
5240
REV.0
03
RV1
E1
5
TP
4
TP
3
TP
2
TP
1
E2
6
1
E18
CR15
R175
E3
8
E4
0
1
E3
0
TVS
2
OF
F
O
N
W
R
G
C
+
1
2
3
4
1
2
3
4
LOW
ER
SLOT
SI
DE
+
+
R
1
R12
4
R12
7
R12
8
R12
9
R13
5
R3
3
R1
R34 R63
4
R7
9
R8
8
R9
7
R10
4
R10
5
R19
8
R20
1
R7
0
R7
2
R55
R65
R4
0
R30
R7
R64
R
3
1
O
R4
N
1
R
5
1
R6
0
R1
84
R
18
2
R5
3
R
45
R6
1
R5
R5
4
R183
OFF
R1 85
R56
R44
R4
7
R18
7
R18
6
R 42
R16
6
R21
2
R9
2
R14
5
R8
9
R9
3
R18
1
R7
6
R7
5
R8
0
R179
R178
R4
9
R4
3
R18
0
R2
2
R5
2
R1
5
R
1
3
R2
8
R1
46
R155
R2
1
R1
2
R1
3
1
R2
3
R1
9
R
4
R
3
R2
0
R1
1
R1
8
R
1
0
R12
0
R14
7
R152
R169
R 1 3 0
R11
0
R113
R121 R115 R126
R125 R123
R11
2
R11
1
R15
1
R13
7
R13
6
R14
4
R
8
R1 93
R150
R168 R170 R149
R148
R4
6
R21
7
E3
7
1
E2
2
E2
8
K
2
K1
0
K
8
K
6
K
7
1
U
1
DS
1
O FF
O N
SW
1
O FF
O N
SW
2
1
2
4
SW
3
CR2
9
CR3
0
CR1
7
2
0
CR1
CR1
3
CR
7
CR
3
CR3
5
CR1
8
CR2
6
CR3
4
CR
2
1
Q1
0
Q1
4
Q
6
CR
1
CR
6
CR1
6
CR2
0
CR2
2
R134 R216
CR28
R133
CR
3
1
R2
CR
23
1
Q
5
Q
3
Q
2
CR19
Q16
Q
9
Q
7
R117 R118 R119
Q8
CR2
4
Q1
1
R16
1
CR32
R162
R160 R163
K9
R157
R16
7
R101
R210
R10
2
R1 03
R8
6
R
85
R32
R 69
R 39
R2
7
CR
4
R19
9
R 91
R8
1
R
6
R15
9
R20
0
R10
9
R20
9
R100
R
96
R14
3
R20
7
R213
R215
CR1R1
96 1
C
R
1
0
R57
R7
R35 1
R48
R9
4
R6
2
R2
9
R98
R173
R12
2
R139
CR27
CR4
R19
5
R82 R1
7
C1
9
C21
R158
C2
3
C1
4
C3
7
C3
8
R50
C3
6
R164
R172
C31
CR9
3
C
3
C2
7
C
18
C33
R132
C2
0
C
1
6
C2
4
C
1
7
C4
4
C1
5
C1
3
C1
1
C1
0
C22
CR25
Q12
R9
C4
C
1
C
2
Q4 R177
R176 C28
CR
33
R95 R171
Q13
R1
38
Q
1
C3
5
C3
4
C3
2
C4
3
C42
K4
C41
K3
K1
C40
C3
0
R11
6 R10
C1
7
2
CR5
D H U M
CR2
Y1
Y/ Y2
R59 R16 R87 R78 CR8
CR 39
FLAME
CURRENT
1VDC=1UA
CR38
R25
R24
R2
6
R37
R36
R3
8
R6
6
R6
7
R6
8
R8
3
R9
0
R9
9
R10
8
R154
R156
R19
7
R14
2
R14
1
R20
2
R20
3
R20
4
R20
5
R20
6
R21
1
R10
6
6
CR14
1
E2
4
W
1
W
2
TP
5
TP
6
TVS1
R58
F
1
C2
6
E3
2
E2
5
E
2
E
1
E
3
E2
9
RV
2
U
5
U
4
U
3
U
2
CR3
6
CR3
7
Q1
8
Q1
9
C2
5
R15
3
R1
40 R11
C4
R
4
E4
2
59-
5240
REV.0
03
RV1
E1
5
TP
4
TP
3
TP
2
TP
1
E2
6
1
E18
CR15
R175
E3
8
E4
0
1
E3
0
TVS
2
ROOM
THERMOSTAT
Y W R G C
CONDENSOR
CONTACTOR COILS
ISOLATING RELAY
(SEE NOTES)
TWINNING CONNECTION DIAGRAM
NOTES:
1. ISOLATING RELAY MAY BE ELIMINATED IF LINE VOLTAGE
SUPPLY TO FURNACES IS THE SAME PHASE .
TO VERIFY PHASING:
A) VERIFY SOURCE IS EXACTLY THE SAME EITHER L1, L2,
OR L3 FROM THE SAME TRANSFORMER OR
B) CHECK WITH SCOPE OR PHASE METER
C) IF IN DOUBT USE RELAY
2. IF ISOLATING RELAY IS NOT USED, CONNECT FURNACE “W” TERMINALS TOGETHER.
