Bryant 821T Installation, Start-Up, Operating And Service And Maintenance Instructions page 42

Table 11 – Orifice Size and Manifold Pressure (In. W.C.) for Gas Input Rate
(Tabulated Data Based on 22,000 Btuh High- -Heat/14,500 Btuh for Low- -Heat per Burner, Derated 4 Percent for Each 1000 Ft.
AVG. GAS
ALTITUDE RANGE
HEAT VALUE
FT. (M)
(BTUH/CU FT.)
0 to
USA 1000
2000
(0 to 610)
1025
1050
1075
1100
AVG. GAS
ALTITUDE RANGE
HEAT VALUE
FT. (M)
(BTUH/CU FT.)
2001 to
USA 3000 (610
to 914)
1000
AVG. GAS
ALTITUDE RANGE
HEAT VALUE
FT. (M)
(BTUH/CU FT.)
3001 to
4000
USA
(914 to
1219)
AVG. GAS
ALTITUDE RANGE
HEAT VALUE
FT. (M)
(BTUH/CU FT.)
4001 to
5000
USA
(1219 to
1524)
* Orifice numbers 43 are factory installed
(305 M) Above Sea Level)
0.58
Manifold
Orifice
Pressure
No.
High/Low
900 42 3.5/1.5
925 42 3.3/1.4
950 43 3.8/1.7
975 43 3.6/1.6
43 3.5/1.5
43 3.3/1.4
44 3.6/1.6
44 3.4/1.5
44 3.3/1.4
0.58
Manifold
Orifice
Pressure
No.
High/Low
800 42 3.4/1.5
825 42 3.2/1.4
850 43 3.7/1.6
875 43 3.5/1.5
900 43 3.3/1.4
925 44 3.5/1.5
950 44 3.4/1.5
975 44 3.2/1.4
45 3.7/1.6
0.58
Manifold
Orifice
Pressure
No.
High/Low
775 42 3.2/1.4
800 43 3.6/1.6
825 43 3.4/1.5
850 43 3.2/1.4
875 44 3.5/1.5
900 44 3.3/1.4
925 45 3.8/1.6
950 46 3.8/1.6
0.58
Manifold
Orifice
Pressure
No.
High/Low
750 43 3.6/1.6
775 43 3.4/1.5
800 43 3.2/1.4
825 44 3.4/1.5
850 44 3.2/1.4
875 45 3.7/1.6
900 46 3.7/1.6
925 46 3.5/1.5
SPECIFIC GRAVITY OF NATURAL GAS
0.60
Manifold
Orifice Orifice
Pressure
No. No.
High/Low
42 3.6/1.6 42
42 3.4/1.5 42
42 3.3/1.4 42
43 3.8/1.6 42
43 3.6/1.6 43
43 3.4/1.5 43
43 3.2/1.4 43
44 3.5/1.5 43
44 3.4/1.5 44
SPECIFIC GRAVITY OF NATURAL GAS
0.60
Manifold
Orifice Orifice
Pressure
No. No.
High/Low
42 3.5/1.5 42
42 3.3/1.4 42
43 3.8/1.6 42
43 3.6/1.6 43
43 3.4/1.5 43
43 3.2/1.4 43
44 3.5/1.5 44
44 3.3/1.4 44
45 3.8/1.7 44
SPECIFIC GRAVITY OF NATURAL GAS
0.60
Manifold
Orifice Orifice
Pressure
No. No.
High/Low
42 3.3/1.4 42
43 3.8/1.6 42
43 3.5/1.5 43
43 3.3/1.4 43
44 3.6/1.6 43
44 3.4/1.5 44
44 3.2/1.4 44
45 3.7/1.6 45
SPECIFIC GRAVITY OF NATURAL GAS
0.60
Manifold
Orifice Orifice
Pressure
No. No.
High/Low
43 3.8/1.6 42
43 3.5/1.5 43
43 3.3/1.4 43
44 3.6/1.5 43
44 3.4/1.5 44
45 3.8/1.7 44
46 3.8/1.7 45
46 3.6/1.6 46
42
0.62 0.64
Manifold Manifold
Orifice
Pressure Pressure
No.
High/Low High/Low
3.7/1.6 41 3.5/1.5
3.5/1.5 42 3.7/1.6
3.4/1.5 42 3.5/1.5
3.2/1.4 42 3.3/1.4
3.7/1.6 43 3.8/1.7
3.5/1.5 43 3.6/1.6
3.4/1.5 43 3.5/1.5
3.2/1.4 43 3.3/1.4
3.5/1.5 43 3.2/1.4
0.62 0.64
Manifold
Manifold
Orifice
Pressure
Pressure
No.
High/Low
High/Low
3.6/1.6 42 3.7/1.6
3.4/1.5 42 3.5/1.5
3.2/1.4 42 3.3/1.4
3.7/1.6 43 3.8/1.7
3.5/1.5 43 3.6/1.6
3.3/1.4 43 3.4/1.5
3.6/1.6 43 3.2/1.4
3.4/1.5 44 3.5/1.5
3.2/1.4 44 3.4/1.5
0.62 0.64
Manifold
Manifold
Orifice
Pressure
Pressure
No.
High/Low
High/Low
3.4/1.5 42 3.5/1.5
3.2/1.4 42 3.3/1.4
3.7/1.6 43 3.8/1.6
3.4/1.5 43 3.6/1.5
3.3/1.4 43 3.4/1.5
3.5/1.5 43 3.2/1.4
3.3/1.5 44 3.4/1.5
3.8/1.7 44 3.3/1.4
0.62 0.64
Manifold
Manifold
Orifice
Pressure
Pressure
No.
High/Low
High/Low
3.2/1.4 42 3.3/1.4
3.6/1.6 43 3.8/1.6
3.4/1.5 43 3.5/1.5
3.2/1.4 43 3.3/1.4
3.5/1.5 44 3.6/1.6
3.3/1.4 44 3.4/1.5
3.7/1.6 44 3.2/1.4
3.7/1.6 46 3.8/1.7