Osburn SATURNA Installation And Operating Instructions Manual page 28

3.3.7.5 Altitude adjustment
All valves have been preset and certified for installation at elevations from 0 - 4500 feet (0-1372m)
above sea level. When installing this insert at higher elevations, it is necessary to decrease the input
rating, by changing the existing burner orifice to a smaller size, consult local codes. Input should be
reduced 4% for each additional 1000 feet above sea level. Use Tables 5A & 5B or check with the
local gas authorities for proper orifice size identification. For the USA, derate the heater from sea
level according to the gas installation code.
Altitude adjustment by changing the burner orifice
ALTITUDE
up to (ft)
4500
5500
6500
7500
8500
9500
10500
11500
ALTITUDE
up to (ft)
4500
5500
6500
7500
8500
9500
10500
11500
(Natural Gas)
REDUCTION ORIFICE SIZE
(%)
-
4
8
12
16
20
24
28
(Propane / LP Gas)
REDUCTION ORIFICE SIZE
(%)
-
4
8
12
16
20
24
28
TARGET
(DMS)
(BTU/hr)
36
37
38
39
40
40
41
42
TABLE 5A
TARGET
(DMS) UNPUT
(BTU/hr)
50 35,000
51 33,600
51 32,200
52 30,800
52 29,400
53 28,000
53 26,600
54 25,200
TABLE 5B
MANIFOLD
INPUT PRESSURE
(in.wc)
35,000
33,600
32,200
30,800
29,400
28,000
26,600
25,200
MANIFOLD
PRESSURE
(in. wc)
3.5
3.5
3.5
3.5
3.5
3.5
3.5
3.5
10
10
10
10
10
10
10
10
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