Table 7: Maximum Capacity of Schedule 40 Pipe in CFH* For natural Gas Pressures of 0.5 psig or Less

Length

 

0.3 Inch w.c. Pressure Drop

 

 

0.5 Inch w.c. Pressure Drop

 

[Feet]

½

 

¾

1

 

½

 

¾

1

 

10

132

 

278

520

 

1,050

175

 

360

680

 

1,400

20

92

 

190

350

 

730

120

 

250

465

 

950

30

73

 

152

285

 

590

97

 

200

375

 

770

40

63

 

130

245

 

500

82

 

170

320

 

660

50

56

 

115

215

 

440

73

 

151

285

 

580

60

50

 

105

195

 

400

66

 

138

260

 

530

70

46

 

96

180

 

370

61

 

125

240

 

490

80

43

 

90

170

 

350

57

 

118

220

 

460

90

40

 

84

160

 

320

53

 

110

205

 

430

100

38

 

79

150

 

305

50

 

103

195

 

400

*1 CFH of Natural Gas is approximately equal to 1 MBH; 1 CFH of LP is approximately equal to 2.5 MBH; con- tact your gas supplier for the actual heating value of your gas.

B.Connect boiler gas valve to gas supply system.

WARNING

Failure to use proper thread compounds on all gas connectors may result in leaks of flammable gas.

WARNING

Gas supply to boiler and system must be absolutely shut off prior to installing or servicing boiler gas piping.

1.Use methods and materials in accordance with local plumbing codes and requirements of gas supplier. In absence of such requirements, follow National Fuel Gas Code, NFPA 54/ANSI Z223.1.

2.Use thread (joint) compounds (pipe dope) resistant to action of liquefied petroleum gas.

3.Install sediment trap, ground-joint union and manual shut-off valve upstream of boiler gas control valve and outside jacket. See Figure 27.

Figure 27: Recommended Gas Piping

Table 8: Equivalent Lengths of Standard Pipe Fittings & Valves

VALVES FULLY OPEN

Pipe

I.D.

Gate

Globe

Angle

Swing

90°

45°

90° Tee, Flow

90° Tee, Flow

Size

Inches

Check

Elbow

Elbow

Through Run

Through Branch

 

 

 

½”

06.22

0.35

18.6

9.3

4.3

1.6

0.78

1.0

3.1

¾”

0.824

0.44

23.1

11.5

5.3

2.1

0.97

1.4

4.1

1”

1.049

0.56

29.4

14.7

6.8

2.6

1.23

1.8

5.3

1¼”

1.380

0.74

38.6

19.3

8.9

3.5

1.60

2.3

6.9

51

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Image 51
Burnham 1100-H4 manual Valves Fully Open