38
Measuring Gas Pressure
In order to check the gas supply pressure to the unit, a
tap is provided on the gas inlet. Remove the hex head
philips screw from the tap, and connect a manometer
using a silicon tube.
In order to check the gas manifold pressure, a pair of
taps are provided on the gas valve inside the unit.
The pressure can be checked either by removing the
hex head philips screw and connecting a manometer
with a silicon tube, or by removing the 1/8" NPT screw
with an allen wrench and connecting the appropriate
pressure gauge.
Natural Gas
Meter
Noritz N-063S or N-069M
(194,000 Btuh)
Clothes Dryer
(35,000 Btuh)
Barbecue
(50,000 Btuh)
Gas Range Stove
(65,000 Btuh)
10'
10'
10'
10'
5'
5'
5'
5'
Gas Fireplace
(25,000 Btuh)
Maximum Natur
Natural Gas Delivery Capacity in Cubic Feet per Hour (0.60 Specific Gravity, 0.5" WC Pressure Drop)
Contact the Gas Supplier for Btu/Cubic Ft. of the Supplied Gas. 1000 BTU/Cubic Ft. is a Typical Value
Maximum Liquified P
Liquified Petroleum (Undiluted) Delivery Capacity in Thousands of Btuh (0.5" WC Pressure Drop)
Instructions
1. Size each outlet branch starting from the furthest
using the Btuh required and the length from the
meter.
2. Size each section of the main line using the
length to the furthest outlet and the Btuh
required by everything after that section.
Sample Gas Line
Sample Calculation
Outlet A: 45' (Use 50'), 50,000 Btuh requires 1/2"
Outlet B: 40', 65,000 Btuh requires 1/2"
Section 1: 45' (Use 50'), 115,000 Btuh requires 3/4"
Outlet C: 30', 35,000 Btuh requires 1/2"
Section 2: 45' (Use 50'), 150,000 Btuh requires 3/4"
Outlet D: 25' (Use 30'), 25,000 Btuh requires 1/2"
Section 3: 45' (Use 50'), 175,000 Btuh requires 1"
Outlet E: 25' (Use 30'), 194,000 Btuh requires 3/4"
Section 4: 45' (Use 50'), 369,000 Btuh requires 1 1/4"
Length in Feet
Length in Feet
Pipe
Size
Pipe
Size
1/2"
1/2"
3/4"
3/4"
1"
1"
1 1/4"
1 1/4"
1 1/2"
1 1/2"
2"
2"
2 1/2"
3"
3 1/2"
4"
10'
20'
30'
40'
50'
60'
70'
80'
90'
100'
125'
10'
20'
30'
40'
50'
60'
70'
80'
90'
100'
125'
150'
200'
174
363
684
1404
2103
4050
6455
11,412
16,709
23,277
119
249
470
965
1445
2784
4437
7843
11,484
15,998
96
200
377
775
1161
2235
3563
6299
9222
12,847
Adapted from UPC 1997
82
171
323
663
993
1913
3049
5391
7893
10,995
73
152
286
588
880
1696
2703
4778
6995
9745
66
138
259
532
798
1536
2449
4329
6338
8830
61
127
239
490
734
1413
2253
3983
5831
8123
56
53
50
44
118
111
104
93
222
208
197
174
456
683
1315
2096
3705
5425
7557
428
641
1234
1966
3476
5090
7091
404
605
1165
1857
3284
4808
6698
358
536
1033
1646
2910
4261
5936
275
567
1071
2205
3307
6221
189
393
732
1496
2299
4331
152
315
590
1212
1858
3465
129
267
504
1039
1559
2992
114
237
448
913
1417
2646
103
217
409
834
1275
2394
96
196
378
771
1181
2205
89
185
346
724
1086
2047
83
173
322
677
1023
1921
78
162
307
630
976
1811
69
146
275
567
866
1606
63
132
252
511
787
1496
55
112
213
440
675
1260
Section 3 Section 2
Section 1
Outlet A
Outlet B
Outlet C
Outlet D
Outlet E
5'
5'
Section 4
Gas Line Sizing