Specifications

Manual 2100-590C
Page 31 of 67
All other orifice sizes shown are available as individual items. See Orifice table on Page 30 for part numbers and number required.
TABLE 8A
NATURAL GAS ORIFICE TABLES FOR MODELS W42G, W48G AND W60G
Factory Standard
Input
Gas Heat* Value
BTU/Cu. Ft.
Up to 6,000 Feet No
Changes Except
for BTU Content
6,001 to 8,000 Feet
Requires Pressure Switch
Change and Orifice
Change Based on BTU
Content
8,001 to 10,000 Feet
Requires Pressure Switch
Change and Orifice Change
Based on BTU Content
25000 BTU
Per Burner
700-749 2.90 2.80 2.70
750-799 2.80 2.70 2.60
800-849 2.70 2.60 2.50
850-899 2.60 2.50 2.45
900-949 2.50 2.45 (2.40)
950-999 2.45 (2.40) 2.35
1000-1049** (2.40) 2.35 [2.30]
1050-1100 [2.30] 2.25 2.20
Pressure Switch Standard (.55) Order 8620-189 High Altitude Pressure Switch Kit (.42)
(2.40) is the standard factory installed orifice size
[2.30] orifices are shipped with the unit for field installed
optional 10% derate
Optional
10% Field
Converted Derate
Gas Heat* Value
BTU/Cu. Ft.
Up to 6,000 Feet No
Changes Except
for BTU Content
6,001 to 8,000 Feet
Requires Pressure Switch
Change and Orifice
Change Based on BTU
Content
8,001 to 10,000 Feet
Requires Pressure Switch
Change and Orifice Change
Based on BTU Content
22250 BTU
Per Burner
700-749 2.75 2.70 2.60
750-799 2.70 2.60 2.50
800-849 2.60 2.50
850-899 2.50 2.45 (2.40)
900-949 (2.40) 2.35 [2.30]
950-999 2.35 [2.30] 2.25
1000-1049** [2.30] 2.25 2.20
1050-1100 2.25 2.25 2.20
Pressure Switch Standard (.55) Order 8620-189 High Altitude Pressure Switch Kit (.42)
[2.30] orifices are shipped with the unit for field installed optional
10% input rate
(2.40) is the factory installed orifice size for full rated input
At standard conditions: 30.00 inches Mercury, 60F, saturated, .60 specific gravity.
All Natural Gas factory orifice sizing and standard input ratings based on nominal 1025 BTU/cu ft gas and sea level conditions
*
**