Burnham Series 8H/8HE Boiler Manual Do Proprietário

Página de 72
56
NOTIcE
  
Use this table only if all of the following conditions 
are met:
1)   50 Ft. maximum plus 3 ells from Meter to furthest 
Module Gas Connection
2)   0.5 PSIG Maximum Gas Pressure
3)   0.3 Inch Water Column Pressure Drop
4)   Specific Gravity of Natural Gas = 0.64 to 0.70 
Propane = 1.50 to 1.63
5)   Heating value of
    Natural Gas = 1000 Btu/Ft
3
    Propane Gas = 2500 Btu/Ft
3
 
  Otherwise, refer to the Alternate Method of Gas Pipe 
Sizing in 4.4.
To use this table:  (1) Total the Input Mbh (from 
figure 2-3) of all modules to be supplied by the 
gas pipe (and/or fitting) to be sized (2) Locate this 
Total Mbh in the left column (3) Move to the right 
to the appropriate gas column (4) Read the pipe 
and/or fitting size.
fIGURE 4-3
EQUIVALENT LENGTH OF FITTINGS AND VALVES - GAS PIPE (FT)
TO UsE ThIs TAbLE:  (1) ENTER LEfT hAND cOLUMN AT REQUIRED PIPE sIZE.   (2) MOVE TO ThE RIGhT 
TO ThE RIGhT TO ThE cOLUMN fOR ThE TyPE Of fITTING.  (3) READ ThE EQUIVALENT LENGTh Of 
sTRAIGhT PIPE fOR ThAT ONE fITTING.  (4)  TOTAL ThE EQUIVALENT LENGTh fOR EVERy fITTING IN 
ThE sUPPLy LINE.  (5)  ADD ThE TOTAL EQUIVALENT LENGTh fOR fITTINGs TO ThE MEAsURED LENGTh 
Of sTRAIGhT PIPE TO ObTAIN ThE EQUIVALENT LENGTh Of ThE sUPPLy LINE.
fIGURE 4-4
Total Input Mbh of 
Module(s) served 
by Pipe/fitting
Pipe/fitting size (NPT)
Natural Gas
Propane Gas
264. - 330.
1¼"
1"
396.
1¼"
1¼"
462. - 660.
1½"
1¼"
726. - 990.
2"
1½"
1056. - 1254.
2"
2"
1320. - 1980.
2½"
2"
2046. - 3102.
3"
2½"
3168. - 3564.
3"
3"
3630. - 5610.
4"
3"
Nominal 
Pipe size, 
In.
Inside Dia., 
schedule 40, 
In.
screwed fittings
Valves (screwed, flanged, or 
welded)
45° Ell
90° Ell
180° close 
Return bends
Tee
Gate
Globe  Angle
swing 
check
½
0.622
0.73
1.55
3.47
3.10
0.36
17.3
8.65
4.32
¾
0.824
0.96
2.06
4.60
4.12
0.48
22.9
11.4
5.72
1
1.019
1.22
2.62
5.82
5.24
0.61
29.1
14.6
7.27
1.380
1.61
3.45
7.66
6.90
0.81
38.3
19.1
9.58
1.610
1.88
4.02
8.95
8.04
0.94
44.7
22.4
11.2
2
2.067
2.41
5.17
11.5
10.3
1.21
57.4
28.7
14.4
2.469
2.88
6.16
13.7
12.3
1.44
68.5
34.3
17.1
3
3.068
3.58
7.67
17.1
15.3
1.79
85.2
42.6
21.3
4
4.026
4.70
10.1
22.4
20.2
2.35
112
56.0
28.0
5
5.047
5.88
12.6
28.0
25.2
2.94
140
70.0
35.0