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9/2019
D-Proper Gas Flow (Approximate)
1- Operate unit at least 15 minutes before checking gas
flow. Determine the time in seconds for
two
revolutions
of gas through the meter. (Two revolutions assures a
more accurate time.) A portable LP gas meter (17Y44)
is available for LP applications.
2-
Divide the number of seconds by two
and compare
to the time in table 23. If manifold pressure is correct
and rate is incorrect, check gas orifices for proper size
and restriction.
3- Remove temporary gas meter if installed.
NOTE- To obtain accurate reading, shut off all other
gas appliances connected to meter.
TABLE 23
GAS METER CLOCKING CHART
Unit
Input
Rate
(Btuh)
Seconds for One Revolution
Natural
LP
1 cu ft
Dial
2 cu ft
Dial
1 cu ft
Dial
2 cu ft
Dial
70,000
51
103
129
257
108,000
33
67
83
167
150,000
24
48
60
120
130,000
28
55
69
138
180,000
20
40
50
100
240,000
15
30
38
75
260,000
14
28
35
69
360,000
10
20
25
50
480,000
8
15
19
38
Natural-1000 btu/cu ft
LP-2500 btu/cu ft
Note: Table assumes standard temperature (60°F), pressure
(30in.Hg.)and fuel heating values (Btuh/Ft.
3
). Apply pressure
corrections in altitudes above 2000 ft.
