Bryant 345MAV - Manual (Page 37)

TABLE 9—MODEL 345MAV ORIFICE SIZE AND MANIFOLD PRESSURE FOR CORRECT INPUT
(TABULATED DATA BASED ON 20,000 BTUH PER BURNER, DERATED 2% 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
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
U.S.A.
and
Canada
850 43 3.7 43 3.8 42 3.2 42 3.3 42 3.4
875 43 3.5 43 3.6 43 3.7 43 3.8 42 3.2
900 44 3.7 43 3.4 43 3.5 43 3.6 43 3.7
0 925 44 3.5 44 3.7 44 3.8 43 3.4 43 3.5
950 44 3.4 44 3.5 44 3.6 44 3.7 44 3.8
to 975 44 3.2 44 3.3 44 3.4 44 3.5 44 3.6
1000 45 3.7 45 3.8 44 3.2 44 3.4 44 3.5
2000 1025 45 3.5 45 3.6 45 3.7 44 3.2 44 3.3
1050 45 3.3 45 3.4 45 3.6 45 3.7 45 3.8
0% 1075 45 3.2 45 3.3 45 3.4 45 3.5 45 3.6
derate 1100 47 3.6 47 3.7 45 3.2 45 3.4 45 3.5
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
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
U.S.A.
and
Canada
U.S.A. 775 43 3.8 42 3.2 42 3.3 42 3.4 42 3.5
Altitudes 800 43 3.5 43 3.7 43 3.8 42 3.2 42 3.3
2001 to 825 44 3.8 43 3.4 43 3.6 43 3.7 43 3.8
3000 850 44 3.6 44 3.7 44 3.8 43 3.5 43 3.6
or 875 44 3.4 44 3.5 44 3.6 44 3.7 43 3.4
Canada 900 44 3.2 44 3.3 44 3.4 44 3.5 44 3.6
Altitudes 925 45 3.7 45 3.8 44 3.2 44 3.3 44 3.4
2001 to 950 45 3.5 45 3.6 45 3.7 45 3.8 44 3.3
4000 975 45 3.3 45 3.4 45 3.5 45 3.6 45 3.8
5% 1000 45 3.1 45 3.2 45 3.4 45 3.5 45 3.6
derate 1025 45 3.0 45 3.1 45 3.2 45 3.3 45 3.4
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
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
U.S.A.
Only
750 43 3.7 43 3.8 42 3.3 42 3.4 42 3.5
775 43 3.5 43 3.6 43 3.7 43 3.8 42 3.2
800 44 3.7 43 3.4 43 3.5 43 3.6 43 3.7
3001 825 44 3.5 44 3.6 44 3.8 43 3.4 43 3.5
850 44 3.3 44 3.4 44 3.5 44 3.7 44 3.8
to 875 45 3.8 44 3.2 44 3.3 44 3.5 44 3.6
900 45 3.6 45 3.7 45 3.8 44 3.3 44 3.4
4000 925 45 3.4 45 3.5 45 3.6 45 3.7 44 3.2
950 45 3.2 45 3.3 45 3.4 45 3.5 45 3.7
7% 975 45 3.0 45 3.2 45 3.3 45 3.4 45 3.5
derate 1000 45 2.9 45 3.0 45 3.1 45 3.2 45 3.3
* Orifice numbers 45 are factory installed.
Percents of derate are based on midpoints of U.S. altitude ranges.
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