Installation & Service Manual

3Gas connections (continued)

TABLE - 3E

GAS PIPING SIZE CHART

Nominal

 

 

 

 

Length of Pipe in Straight Feet

 

 

 

 

 

Maximum

Iron Pipe

 

 

 

 

 

 

 

 

 

Size

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Capacity of Pipe

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

in Thousands of

Inches

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

10

20

30

40

50

60

70

80

90

 

100

125

150

175

200

Btu/hr per hour

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

for gas pressures

3/4

369

256

205

174

155

141

128

121

113

 

106

95

86

79

74

 

of 13.5 Inches

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

697

477

384

328

292

267

246

226

210

 

200

179

164

149

138

Water Column

 

(0.5 PSIG) or less

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 1/4

1,400

974

789

677

595

543

502

472

441

 

410

369

333

308

287

and a pressure

 

drop of 0.5 Inch

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 1/2

2,150

1,500

1,210

1,020

923

830

769

707

666

 

636

564

513

472

441

Water Column

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(Based on NAT

2

4,100

2,820

2,260

1,950

1,720

1,560

1,440

1,330

1,250

 

1,180

1,100

974

871

820

 

GAS, 1025

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Btu/hr per Cubic

2 1/2

6,460

4,460

3,610

3,100

2,720

2,460

2,310

2,100

2,000

 

1,900

1,700

1,540

1,400

1,300

 

Foot of Gas and

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.60 Specific

3

11,200

7,900

6,400

5,400

4,870

4,410

4,000

3,800

3,540

 

3,300

3,000

2,720

2,500

2,340

 

Gravity)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4

23,500

16,100

13,100

11,100

10,000

9,000

8,300

7,690

7,380

 

6,870

6,150

5,640

5,130

4,720

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Gas Piping

GAS VALVE

GAS SHUTOFF VALVE

TRAP

(DRIP LEG)

Figure 3-1_Gas Line Connection

All gas connections must be made with pipe joint compound resistant to the action of liquefied petroleum and natural gas. All piping must comply with local codes. Tubing installations must comply with approved standards and practices. Reference FIG. 3-1 for a typical installation.

Install Piping to Control

1.The gas line should be a separate line direct from the meter unless the existing gas line is of sufficient capacity. Verify pipe size with your gas supplier.

2.Use new, properly threaded black iron pipe free from chips. If tubing is used, make sure the ends are cut squared, deburred and clean. All tubing bends must be smooth and without deformation. Avoid flexible gas connections. Internal diameter of flexible lines may not provide proper volume of gas.

3.Run pipe or tubing to the gas valve or manifold inlet. If tubing is used, obtain a tube to pipe coupling to connect the tubing to the gas valve or manifold inlet.

4.DO NOT OVER TIGHTEN. Over tightening may result in damage to the gas valves. Valve distortion or malfunction may result if the pipe is inserted too deeply into the gas valve.

5.Apply a moderate amount of good quality pipe compound (DO NOT use Teflon tape) to pipe only, leaving two end threads bare.

6.Remove seal over gas valve or manifold inlet.

7.Connect pipe to gas valve or manifold inlet. Use wrench to square ends of the gas valve (FIG. 3-2).

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Lochinvar 260000, 45000 service manual Gas Piping, Install Piping to Control