Installation guide

Table 15--Orifice Size* and Manifold Pressure (In. W.C.) for Gas Input Rate
(Tabulated data based on 21,000 btuh per burner, derated 4 percent for each 1000 ft. (305 M) above sea level)
SPECiFiC GRAVITY OF NATURAL GAS
ALTITUDE AVG, GAS 0.58 0.60 0.62 0.64
RANGE HEAT VALUE
FT. (M) AT ALTITUDE Orifice Manifold Orifice Manifold Orifice Manifold Orifice Manifold
(BTU/CU FT.) No. Pressure No. Pressure No. Pressure No. Pressure
900 42 3.2 42 3.3 42 3.4 42 3.5
925 43 3.7 43 3.8 42 3.2 42 3.3
950 43 3.5 43 3.6 43 3.7 43 3.8
975 43 3.3 43 3.4 43 3.5 43 3.7
0 to 2000
U,S,A. 1000 44 3.6 43 3.3 43 3.4 43 3.5
(0 to 610)
1025 44 3.4 44 3.6 43 3.2 43 3.3
1050 44 3.3 44 3.4 44 3.5 43 3.2
1075 45 3.8 44 3.2 44 3.3 44 3.4
11 O0 46 3.8 45 3.7 44 3.2 44 3.3
800 43 3.8 42 3.2 42 3.3 42 3.4
825 43 3.5 43 3.7 43 3.8 42 3.2
850 43 3.3 43 3.5 43 3.6 43 3.7
2001 to 875 43 312 43 3.3 43 314 43 315
U,S,A. 3000 900 43 3.0 43 3.1 43 3.2 43 3.3
(610 to
914) 925 43 2.8 43 2.9 43 3.0 43 3.1
950 43 2.7 43 2.8 43 2.9 43 2.9
975 43 2.5 43 2.6 43 2.7 43 2.8
1000 43 2.4 43 2.5 43 2.6 43 2.7
775 43 3.5 43 3.7 43 3.8 42 3.2
800 43 3.3 43 3.4 43 3.5 43 3.7
3001 to 825 43 3.1 43 3.2 43 3.3 43 3.4
U,S,A. 4000 850 43 2.9 43 3.0 43 3.1 43 3.2
(914 to 875 43 2.8 43 2.9 43 3.0 43 3.1
1219) 900 43 2.6 43 2.7 43 2.8 43 2.9
925 43 2.5 43 2.6 43 2.7 43 2.7
950 43 2.4 43 2.4 43 2.5 43 2.6
750 43 3.3 43 3.4 43 3.5 43 3.6
4001 to
U,S,A. 5000
(1219 to
1524)
775 43 3.1 43 3.2 43 3.3 43 3.4
800 43 2.9 43 3.0 43 3.1 43 3.2
825 43 2.7 43 2.8 43 2.9 43 3.0
850 43 2.6 43 2.7 43 2.8 43 2.8
875 43 2.4 43 2.5 43 2.6 43 2.7
900 43 2.3 43 2.4 43 2.5 43 2.5
925 43 2.2 43 2.2 43 2.3 43 2.4
* Orifice numbers 43 are factor" installed.
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