Carrier 120/C Series Installation, Start-Up, Operating And Service And Maintenance Instructions page 41

Table 12—Orifice Size* and Manifold Pressure For Gas Input Rate
(Tabulated Data Based On 21,000 Btuh Per Burner, Derated 4 Percent For Each 1000 Ft Above Sea Level)
ALTITUDE
RANGE
(FT)
0
to
2000
ALTITUDE
RANGE
(FT)
U.S.A.
Altitudes
2001
to
3000
or
Canada
Altitudes
2000
to
4500
ALTITUDE
RANGE
(FT)
3001
U.S.A. Only to
4000
ALTITUDE
RANGE
(FT)
4001
to
5000
* Orifice numbers 43 are factory installed
AVG GAS
0.58
HEAT VALUE
Orifice Manifold
(BTU/CU FT)
No. Pressure
900 42
925 43
950 43
975 43
1000 44
1025 44
1050 44
1075 45
1100 46
AVG GAS
0.58
HEAT VALUE
Orifice Manifold
(BTU/CU FT)
No. Pressure
800 43
825 43
850 43
875 43
900 43
925 43
950 43
975 43
1000 43
AVG GAS
0.58
HEAT VALUE
Orifice Manifold
(BTU/CU FT)
No. Pressure
775 43
800 43
825 43
850 43
875 43
900 43
925 43
950 43
AVG GAS
0.58
HEAT VALUE
Orifice Manifold
(BTU/CU FT)
No. Pressure
750 43
775 43
800 43
825 43
850 43
875 43
900 43
925 43
SPECIFIC GRAVITY OF NATURAL GAS
0.60
Orifice Manifold
No. Pressure
3.2 42 3.3
3.7 43 3.8
3.5 43 3.6
3.3 43 3.4
3.6 43 3.3
3.4 44 3.6
3.3 44 3.4
3.8 44 3.2
3.8 45 3.7
SPECIFIC GRAVITY OF NATURAL GAS
0.60
Orifice Manifold
No. Pressure
3.8 42 3.2
3.5 43 3.7
3.3 43 3.5
3.2 43 3.3
3.0 43 3.1
2.8 43 2.9
2.7 43 2.8
2.5 43 2.6
2.4 43 2.5
SPECIFIC GRAVITY OF NATURAL GAS
0.60
Orifice Manifold
No. Pressure
3.5 43 3.7
3.3 43 3.4
3.1 43 3.2
2.9 43 3.0
2.8 43 2.9
2.6 43 2.7
2.5 43 2.6
2.4 43 2.4
SPECIFIC GRAVITY OF NATURAL GAS
0.60
Orifice Manifold
No. Pressure
3.3 43 3.4
3.1 43 3.2
2.9 43 3.0
2.7 43 2.8
2.6 43 2.7
2.4 43 2.5
2.3 43 2.4
2.2 43 2.2
41
0.62
Orifice Manifold Orifice
No. Pressure No.
42 3.4 42
42 3.2 42
43 3.7 43
43 3.5 43
43 3.4 43
43 3.2 43
44 3.5 43
44 3.3 44
44 3.2 44
0.62
Orifice Manifold Orifice
No. Pressure No.
42 3.3 42
43 3.8 42
43 3.6 43
43 3.4 43
43 3.2 43
43 3.0 43
43 2.9 43
43 2.7 43
43 2.6 43
0.62
Orifice Manifold Orifice
No. Pressure No.
43 3.8 42
43 3.5 43
43 3.3 43
43 3.1 43
43 3.0 43
43 2.8 43
43 2.7 43
43 2.5 43
0.62
Orifice Manifold Orifice
No. Pressure No.
43 3.5 43
43 3.3 43
43 3.1 43
43 2.9 43
43 2.8 43
43 2.6 43
43 2.5 43
43 2.3 43
0.64
Manifold
Pressure
3.5
3.3
3.8
3.7
3.5
3.3
3.2
3.4
3.3
0.64
Manifold
Pressure
3.4
3.2
3.7
3.5
3.3
3.1
2.9
2.8
2.7
0.64
Manifold
Pressure
3.2
3.7
3.4
3.2
3.1
2.9
2.7
2.6
0.64
Manifold
Pressure
3.6
3.4
3.2
3.0
2.8
2.7
2.5
2.4