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Table 10—Model 58TMA Orifice Size and Manifold Pressure for Correct Input
(Tabulated Data Based on 21,000 Btuh High Heat/13,500 Btuh Low Heat per Burner,
Derated 4% for Each 1000 Ft Above Sea Level)*
ALTITUDE
RANGE
(FT)
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
SPECIFIC GRAVITY OF NATURAL GAS
0.58
0.60
0.62
0.64
0.66
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
U.S.A.
and
Canada
850
42
3.3/1.4
42
3.4/1.4
42
3.5/1.5
42
3.7/1.5
42
3.8/1.6
875
43
3.8/1.6
42
3.2/1.3
42
3.3/1.4
42
3.5/1.4
42
3.6/1.5
900
43
3.6/1.5
43
3.7/1.5
42
3.2/1.3
42
3.3/1.3
42
3.4/1.4
0
925
43
3.4/1.4
43
3.5/1.5
43
3.6/1.5
43
3.8/1.6
42
3.2/1.3
950
44
3.7/1.5
44
3.8/1.6
43
3.5/1.4
43
3.6/1.5
43
3.7/1.5
to
975
44
3.5/1.5
44
3.6/1.5
44
3.8/1.6
43
3.4/1.4
43
3.5/1.4
1000
44
3.3/1.4
44
3.5/1.4
44
3.6/1.5
44
3.7/1.5
44
3.8/1.6
2000
1025
44
3.2/1.3
44
3.3/1.4
44
3.4/1.4
44
3.5/1.5
44
3.6/1.5
1050
45
3.7/1.5
45
3.8/1.6
44
3.2/1.3
44
3.4/1.4
44
3.5/1.4
1075
46
3.7/1.5
46
3.8/1.6
45
3.7/1.5
44
3.2/1.3
44
3.3/1.4
1100
46
3.5/1.5
46
3.6/1.5
46
3.8/1.6
45
3.7/1.5
45
3.8/1.6
ALTITUDE
RANGE
(FT)
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
SPECIFIC GRAVITY OF NATURAL GAS
0.58
0.60
0.62
0.64
0.66
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
U.S.A.
and
Canada
U.S.A.
775
43
3.7/1.5
42
3.2/1.3
42
3.3/1.4
42
3.4/1.4
42
3.5/1.4
Altitudes
800
43
3.5/1.4
43
3.6/1.5
43
3.7/1.5
42
3.2/1.3
42
3.3/1.3
2001
825
44
3.8/1.6
43
3.4/1.4
43
3.5/1.5
43
3.6/1.5
43
3.7/1.5
to
850
44
3.6/1.5
44
3.7/1.5
44
3.8/1.6
43
3.4/1.4
43
3.5/1.5
3000
875
44
3.4/1.4
44
3.5/1.4
44
3.6/1.5
44
3.7/1.5
44
3.8/1.6
or
900
44
3.2/1.3
44
3.3/1.4
44
3.4/1.4
44
3.5/1.4
44
3.6/1.5
Canada
925
46
3.8/1.6
45
3.8/1.6
44
3.2/1.3
44
3.3/1.4
44
3.4/1.4
Altitudes
950
46
3.6/1.5
46
3.7/1.5
45
3.7/1.5
45
3.8/1.6
44
3.2/1.3
2000
975
46
3.4/1.4
46
3.5/1.5
46
3.7/1.5
46
3.8/1.6
45
3.7/1.5
to
1000
47
3.7/1.5
47
3.8/1.6
46
3.5/1.4
46
3.6/1.5
46
3.7/1.5
4500
1025
47
3.5/1.5
47
3.6/1.5
47
3.8/1.6
46
3.4/1.4
46
3.5/1.5
ALTITUDE
RANGE
(FT)
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
SPECIFIC GRAVITY OF NATURAL GAS
0.58
0.60
0.62
0.64
0.66
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
U.S.A.
Only
750
43
3.5/1.4
43
3.6/1.5
43
3.7/1.5
42
3.2/1.3
42
3.3/1.4
775
44
3.8/1.6
43
3.4/1.4
43
3.5/1.4
43
3.6/1.5
43
3.7/1.5
800
44
3.5/1.5
44
3.7/1.5
44
3.8/1.6
43
3.4/1.4
43
3.5/1.4
3001
825
44
3.3/1.4
44
3.4/1.4
44
3.5/1.5
44
3.7/1.5
44
3.8/1.6
850
45
3.8/1.6
44
3.2/1.3
44
3.3/1.4
44
3.4/1.4
44
3.6/1.5
to
875
46
3.7/1.5
45
3.7/1.5
44
3.2/1.3
44
3.3/1.3
44
3.4/1.4
900
46
3.5/1.5
46
3.7/1.5
46
3.8/1.6
45
3.7/1.5
44
3.2/1.3
4000
925
47
3.8/1.6
46
3.5/1.4
46
3.6/1.5
46
3.7/1.5
46
3.8/1.6
950
47
3.6/1.5
47
3.7/1.5
46
3.4/1.4
46
3.5/1.5
46
3.6/1.5
975
47
3.4/1.4
47
3.5/1.5
47
3.7/1.5
47
3.8/1.6
46
3.4/1.4
1000
48
3.7/1.5
48
3.8/1.6
47
3.5/1.4
47
3.6/1.5
47
3.7/1.5
* For 125-20 size only, input is 20,500 Btuh for high fire. Deduct 0.1-in. from manifold pressure shown in table. Change orifice size if manifold pressure falls below 3.2-in.
wc.
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