Pressure testing supply piping, Sizing gas supply lines, Gas connection requirements – Reznor VR Unit Installation Manual User Manual
Page 22
Form I-VR, P/N 205202 R13, Page 21
WARNING: This appliance is equipped for a maximum gas supply pressure of 1/2
pound, 8 ounces, or 14 inches water column.
NOTE: Supply pressure higher than 1/2 pound requires installation of an additional service regulator external
to the unit.
PRESSURE TESTING SUPPLY PIPING
Test Pressures Above 1/2 PSI: Disconnect the heater and manual valve from the gas supply line which is
to be tested. Cap or plug the supply line.
Test Pressures Below 1/2 PSI: Before testing, close the manual valve on the heater.
Sizing
Gas
Supply
Lines
Capacity of Piping
Cubic Feet per Hour based on 0.3” w.c. Pressure Drop
Specific Gravity for Natural Gas -- 0.6 (Natural Gas -- 1000 BTU/Cubic Ft)
Specific Gravity for Propane Gas -- 1.6 (Propane Gas -- 2550 BTU/Cubic Ft)
Length
Diameter of Pipe
of
1/2”
3/4”
1”
1-1/4”
1-1/2”
2”
Pipe Natural Propane Natural Propane Natural Propane Natural Propane Natural Propane Natural Propane
20’
92
56
190
116
350
214
730
445
1100
671
2100
1281
30’
73
45
152
93
285
174
590
360
890
543
1650
1007
40’
63
38
130
79
245
149
500
305
760
464
1450
885
50’
56
34
115
70
215
131
440
268
670
409
1270
775
60’
50
31
105
64
195
119
400
244
610
372
1105
674
70’
46
28
96
59
180
110
370
226
560
342
1050
641
80’
43
26
90
55
170
104
350
214
530
323
990
604
90’
40
24
84
51
160
98
320
195
490
299
930
567
100’
38
23
79
48
150
92
305
186
460
281
870
531
125’
34
21
72
44
130
79
275
168
410
250
780
476
150’
31
19
64
39
120
73
250
153
380
232
710
433
175’
28
17
59
36
110
67
225
137
350
214
650
397
200’
26
16
55
34
100
61
210
128
320
195
610
372
Note: When sizing supply lines, consider possibilities of future expansion and increased requirements.
Refer to National Fuel Gas Code for additional information on line sizing.
DANGER: Do not install gas piping where it may be exposed to radiant or convection
heat. See Hazard Levels, page 2.
Since the tubular heater does expand and contract, the connection between the
supply line and the heater must allow for expansion and contraction. Use only
an agency certified, stainless steel connector with a length of 36” (9140mm)
and a minimum size of 3/4” I.D.
Canadian Installation NOTE: The Natural Gas and Propane Installation Code,
CAN/CSA B149.1, requires a Type I hose connector certified to CAN/CGA-8.1
with a length of 36 (±6) inches / 90 (±15) cm. Type I hose is field supplied when
required.
In the United States, if a 36” stainless flexible connector, Option CE4, was
ordered with the heater, it will be shipped separately. Pressure drops for Option
CE4 stainless flexible connector are listed in the table below.
A shutoff valve and a drip leg or sediment trap must be provided in the gas sup-
ply line at each heater. See
FIGURE 23, page 22.
Pressure Drop (Inches W.C.)
BTUH Input Option CE4, 3/4” I.D.
50,000
0.05
75,000
0.05
100,000
0.10
125,000
0.15
150,000
0.20
175,000
0.40
200,000
0.50
WARNING: Strong
cleaning solutions
or chemical
substances must
not come in
contact with the
flexible connector.
Gas Connection
Requirements