beautypg.com

Optional equipment (cont'd), Sizing gas supply lines, 2 gas piping and pressures (cont'd) – Reznor RECC Unit Installation Manual User Manual

Page 56

background image

Form I-MAPSIII&IV, Page 56

WARNING

The operating valve is the prime safety shutoff. All gas supply

lines must be free of dirt or scale before connecting the unit to

ensure positive closure.

9. Optional

Equipment

(cont'd)

WARNING

All components of a gas supply system must be leak tested prior to placing equipment in

service. NEVER TEST FOR LEAKS WITH AN OPEN FLAME. Failure to comply could result

in personal injury, property damage or death.

Sizing Gas Supply

Lines

Capacity of Piping

Cubic Feet per Hour based on 0.3" w.c. Pressure Drop

Specific Gravity for Natural Gas -- 0.6 (Natural Gas -- 1000 BTU/Cubic Ft)

Specific Gravity for Propane Gas -- 1.6 (Propane Gas -- 2550 BTU/Cubic Ft)

Length

Diameter of Pipe

of

1/2"

3/4"

1"

1-1/4"

1-1/2"

2"

Pipe

Natural Propane Natural Propane Natural Propane Natural Propane Natural Propane Natural Propane

20'

92

56

190

116

350

214

730

445

1100

671

2100

1281

30'

73

45

152

93

285

174

590

360

890

543

1650

1007

40'

63

38

130

79

245

149

500

305

760

464

1450

885

50'

56

34

115

70

215

131

440

268

670

409

1270

775

60'

50

31

105

64

195

119

400

244

610

372

1105

674

70'

46

28

96

59

180

110

370

226

560

342

1050

641

80'

43

26

90

55

170

104

350

214

530

323

990

604

90'

40

24

84

51

160

98

320

195

490

299

930

567

100'

38

23

79

48

150

92

305

186

460

281

870

531

125'

34

21

72

44

130

79

275

168

410

250

780

476

150'

31

19

64

39

120

73

250

153

380

232

710

433

175'

28

17

59

36

110

67

225

137

350

214

650

397

200'

26

16

55

34

100

61

210

128

320

195

610

372

Note: When sizing supply lines, consider possibilities of future expansion and increased requirements.

Refer to National Fuel Gas Code for additional information on line sizing.

Cabinet

Size

Heat Section

Gas Connection

Natural Gas

Propane

A

100, 150, 200

1/2”

1/2”

B

250, 300

3/4”

3/4”

C

400, 500, 600, 700

1”

--

D

500, 600, 700, 800,

100, 1200, 1400,

1600

1”

--

Manual

Valve

Drip Leg

Union

Reduce supply line.

Gas connection

is 1” npt.

FIGURE 37 - Gas Connection

(D Cabinet illustrated)

Supply Pressures

Before attempting to measure valve outlet and manifold gas pressure, the inlet supply

pressure must be within the specified range both when the heater is in operation and

on standby. Incorrect inlet pressure could cause excessive valve outlet gas pressure

immediately or at some future time.
Natural gas inlet supply pressure for all gas control systems must be a minimum of 6.0"

w.c. Maximum natural gas supply pressure is 14" w.c.

Furnaces for natural gas are orificed for operating with gas having a heating value of

1000 (±50) BTU per cubic ft. If the gas at the installation does not meet this specifica-

tion, consult the factory for proper orifice.
Pipe joint compounds (pipe dope) shall be resistant to the action of liquefied petroleum

gas or any other chemical constituents of the gas being supplied.

9.2 Gas Heat -

Models RDCB,

RDDB, RDCC,

RDDC (cont'd)

9.2.1.2 Gas Piping and Pressures (cont'd)