Gas Line Pipe Sizing; Gas Pressure Check - Majestic fireplaces UVHK23MP Installation And Operating Instructions Manual

NOTE: To determine the size of the branch gas line from the main gas line to the fireplace, enter the tables below (for
iron pipe or copper tubing) using the distance from the gas meter or second stage regulator to the furthest appliance on
the gas system. Select a pipe or tube diameter which has enough capacity to meet the maximum input requirement of
the fireplace. Regardless, do not use less than 1/2" diameter for the branch line. For any distances required longer than
shown in these tables, refer to the National Fuel Gas Code.
NOTE: There may be a local gas utility requirement specifying a minimum diameter for gas piping. All units require a 1/2 inch pipe con-
nection at the gas valve.
Length
of 1/2" D
Pipe Natural
20' 92
30' 73
40' 63
50' 56
60' 50
70' 46
90' 40
100' 38
Tubing Length
Feet
10
20
30
40
50
60
80
100
WARNING: Use only internally tinned copper tubing. If correct copper tubing is not used, tubing can deteriorate and develop
gas leaks.

Gas Pressure Check

Check the inlet pressure to the appliance to ensure that it is as
shown in Table 1. Also check the incoming gas pressure where
the field installed gas line connects to the gas logs.
The manifold pressure is controlled by the regulator and should
be checked at the pressure test point located downstream from
the regulator on the control valve body. Access to the pressure
test point is obtained by removing all logs and the heat shield
on the right hand rear side of the base. The pressure test point
1/8" NPT plugged tapping is located on the rear face of the
control body. (Fig. 5)
The pressure should be checked with the appliance burning on
high (highest setting) and all other gas appliances turned on.
One must then read the manometer and if pressures are not
10" w.c. for LP or 3.5" w.c. for natural gas, then the inlet pres-
sure must be adjusted or increased until the proper pressures
are attained. If these pressures are greater than 10" w.c. for
LP or 3.5" w.c. for natural gas, contact your gas supplier before
operating the appliance.
The pressure regulator is preset and locked to prevent tamper-
ing. If the pressure is not as specified, replace the regulator
with part # 73332 (for natural gas only), or part # 73333 (for L.P.
gas only).
12

Gas Line Pipe Sizing

Cubic Feet per Hour based on 0.3" w.c. Pressure Drop
Specific Gravity for Natural Gas - 0.6 (1000 BTU/Cubic Foot)
Specific Gravity for Propane Gas - 1.6 (2550 BTU/Cubic Foot)
Nominal Inches for Iron Pipe Sizes (1,000s BTU/hr)
3/4" D
Propane Natural Propane
143 190 296
115 152 237
97 130 202
87 115 179
79 105 163
71 96 151
61 84 130
59 79 122
Outside Diameter Copper Tubing, Type L (1,000s BTU/hr)
1/2"
0.43
110
76
61
52
46
42
36
32
CAPACITY OF PIPING
1" D
Natural Propane
350 546
285 444
245 380
215 334
196 304
180 280
160 250
150 235
5/8"
0.545
206
141
114
97
86
78
67
59
Table 1
Gas Inlet Pressure
Regulator Pressure
*Minimum inlet supply pressure for the purpose of input adjustment.
After measuring the pressure, replace the test point plug and
check for leaks. Replace the control box cover and the two
phillips head screws.
CAUTION: If the appliance's operating pressures are not
checked and adjusted, improper combustion may result in soot
being produced.
Fig. 5 Pressure test point.
1¹⁄₄" D
Natural Propane Natural
730 1135
590 918
500 778
440 683
400 622
370 576
320 497
305 474
3/4" 7/8"
0.666 0.785
348 536
239 368
192 296
164 256
146 224
132 203
113 174
100 154
Natural
Max. 10.5" w.c.
Normal 7" w.c.
Min.* 5.5" w.c.
3.5" w.c.
Test Point
T126
1¹⁄₂" D
Propane
1100 1711
890 1385
760 1183
670 1043
610 949
560 872
490 763
460 717
Propane
13" w.c.
11" w.c.
11" w.c.
10.0" w.c.
T126
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