Boilers For Use At High Altitude - UTICA BOILERS UB90-50 Installation Manual

The boilers (with the exception of the 90-75 LP product)
are factory equipped for operation at altitudes ranging from
0-10,000 feet above sea level. No changes to the factory settings
are required for installations from 0-5,000 feet above sea level.
For altitudes from 5,000-10,000 feet above sea level the gas
manifold pressure will need to be adjusted based upon calorific
(Btu) value of supply gas (contact local gas utility or distributor
for this value). For specific settings refer to Table #1 for natural
gas applications and Table #2 for LP gas applications. Instruc-
tions on how to adjust the gas manifold pressure settings are
shown in Figures #17 & #18.
Altitude in Ft.
Normal Input (MBH)
Manifold Pressure In W.C.
Orifice
Altitude in Ft.
Normal Input (MBH)
Manifold Pressure In W.C.
Orifice
Altitude in Ft.
Normal Input (MBH)
Manifold Pressure In W.C.
Orifice
++Contact local gas utility or distributor for Btu value of gas.

BOILERS FOR USE AT HIGH ALTITUDE

TABLE #1: SERIES 90 NATURAL GAS
series 90-50
stock Factory
settings 750
0-5,000
50
2.5
43331094
series 90-75
stock Factory
settings 750
0-5,000
75
2.5
43331092
series 90-100
stock Factory
settings 750
0-5,000
100
2.5
43331090
7
Note that 90-75 LP applications for 5,000 - 10,000 feet above
sea level will require an orifice change as well as a gas manifold
pressure adjustment based upon calorific (Btu) value of supply
gas. Refer to Table #2 for altitude orifice kit part number. For
replacing the orifice refer to specific instructions included with
the kit.
Btu Value of Natural Gas++
850 950
5,000-10,000
– –
4 4 3.5
43331094
Btu Value of Natural Gas++
850 950
5,000-10,000
– –
3.5 3.5 2.5
43331092
Btu Value of Natural Gas++
850 950
5,000-10,000
– –
3.5 3.5 2.5
43331090
1000 1050
– –
2.5
1000 1050
– –
2.5
1000 1050
– –
2.5
–
2.5
–
2.5
–
2.5