28
Table 9 -- Orifice Size and Manifold Pressure (In. W.C.) for Gas Input Rate (Con’t.)
(Tabulated Data Based on 21,000 Btuh High--Heat/14,500 Btuh for Low--Heat Per Burner, Derated 4 Percent for Each 1000 Ft.
(305 M) Above Sea level)
ALTITUDE RANGE
FT. (M)
AVG. GAS
HEAT VALUE
AT ALTITUDE
(BTUH/CU
FT.)
SPECIFIC GRAVITY OF NATURAL GAS
0.58
0.60
0.62
0.64
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
USA
5001 to
6000
(1524 to
1829)
725
44
3.5/1.7
43
3.2/1.5
43
3.3/1.6
43
3.4/1.6
750
44
3.3/1.6
44
3.4/1.6
44
3.5/1.7
43
3.2/1.5
775
45
3.7/1.8
44
3.2/1.5
44
3.3/1.6
44
3.4/1.6
800
46
3.7/1.8
46
3.8/1.8
45
3.8/1.8
44
3.2/1.5
825
46
3.5/1.7
46
3.6/1.7
46
3.7/1.8
46
3.8/1.8
850
47
3.7/1.8
47
3.8/1.8
46
3.5/1.7
46
3.6/1.7
875
47
3.5/1.7
47
3.6/1.7
47
3.7/1.8
46
3.4/1.6
900
48
3.8/1.8
47
3.4/1.6
47
3.5/1.7
47
3.7/1.7
ALTITUDE RANGE
FT. (M)
AVG. GAS
HEAT VALUE
AT ALTITUDE
(BTUH/CU
FT.)
SPECIFIC GRAVITY OF NATURAL GAS
0.58
0.60
0.62
0.64
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
USA
6001 to
7000
(1829 to
2134)
675
44
3.5/1.7
43
3.2/1.5
43
3.3/1.6
43
3.4/1.6
700
44
3.3/1.6
44
3.4/1.6
44
3.5/1.7
43
3.2/1.5
725
45
3.7/1.8
45
3.8/1.8
44
3.3/1.6
44
3.4/1.6
750
46
3.6/1.7
46
3.8/1.8
45
3.7/1.8
45
3.8/1.8
775
46
3.4/1.6
46
3.5/1.7
46
3.6/1.7
46
3.8/1.8
800
47
3.6/1.7
47
3.8/1.8
46
3.4/1.6
46
3.5/1.7
825
47
3.4/1.6
47
3.5/1.7
47
3.6/1.7
47
3.8/1.8
850
48
3.7/1.7
48
3.8/1.8
47
3.4/1.6
47
3.5/1.7
ALTITUDE RANGE
FT. (M)
AVG. GAS
HEAT VALUE
AT ALTITUDE
(BTUH/CU
FT.)
SPECIFIC GRAVITY OF NATURAL GAS
0.58
0.60
0.62
0.64
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
USA
7001 to
8000
(2134 to
2438)
650
44
3.3/1.6
44
3.4/1.6
44
3.5/1.7
43
3.2/1.5
675
45
3.7/1.8
45
3.8/1.8
44
3.3/1.6
44
3.4/1.6
700
46
3.6/1.7
46
3.7/1.8
46
3.8/1.8
45
3.8/1.8
725
47
3.8/1.8
46
3.5/1.7
46
3.6/1.7
46
3.7/1.8
750
47
3.5/1.7
47
3.7/1.8
47
3.8/1.8
46
3.5/1.6
775
48
3.8/1.8
47
3.4/1.6
47
3.6/1.7
47
3.7/1.7
800
48
3.6/1.7
48
3.7/1.8
48
3.8/1.8
47
3.4/1.6
825
48
3.3/1.6
48
3.5/1.6
48
3.6/1.7
48
3.7/1.8
ALTITUDE RANGE
FT. (M)
AVG. GAS
HEAT VALUE
AT ALTITUDE
(BTUH/CU
FT.)
SPECIFIC GRAVITY OF NATURAL GAS
0.58
0.60
0.62
0.64
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
Orifice
No.
Manifold
Pressure
High/Low
USA
8001 to
9000
(2438 to
2743)
625
45
3.7/1.8
45
3.8/1.8
44
3.3/1.6
44
3.4/1.6
650
46
3.6/1.7
46
3.7/1.8
46
3.8/1.8
45
3.8/1.8
675
47
3.8/1.8
46
3.4/1.6
46
3.5/1.7
46
3.7/1.7
700
47
3.5/1.7
47
3.6/1.7
47
3.7/1.8
46
3.4/1.6
725
48
3.7/1.8
48
3.8/1.8
47
3.5/1.7
47
3.6/1.7
750
48
3.5/1.7
48
3.6/1.7
48
3.7/1.8
48
3.8/1.8
775
49
3.8/1.8
48
3.4/1.6
48
3.5/1.7
48
3.6/1.7
USA
9001 to
10,000
(2743 to
3048)
600
46
3.6/1.7
46
3.7/1.8
46
3.8/1.8
45
3.7/1.8
625
47
3.7/1.8
47
3.8/1.8
46
3.5/1.7
46
3.6/1.7
650
47
3.4/1.6
47
3.6/1.7
47
3.7/1.8
47
3.8/1.8
675
48
3.6/1.7
48
3.8/1.8
47
3.4/1.6
47
3.5/1.7
700
48
3.4/1.6
48
3.5/1.7
48
3.6/1.7
48
3.7/1.8
725
49
3.7/1.8
49
3.8/1.8
48
3.4/1.6
48
3.5/1.7
* Orifice number 43 are factory installed