Goodman Mfg VC8 User Manual

21

A gas detecting warning system is the only reliable way to
detect a propane gas leak. Rust can reduce the level of odorant
in propane gas.  Do not rely on your sense of smell.  Contact a
local propane gas supplier about installing a gas detecting
warning system.  If the presence of gas is suspected, follow
the instructions on Page 3 of this manual.

All propane gas equipment must conform to the safety stan-
dards of the National Board of Fire Underwriters, NBFU Manual
58.

For satisfactory operation, propane gas pressure must be 10
inch WC at the furnace manifold with all gas appliances in
operation. Maintaining proper gas pressure depends on three
main factors:

1. Vaporization rate, depending on temperature of the liquid,

and “wetted surface” area of the container or containers.

2. Proper pressure regulation. (Two-stage regulation is

recommended for both cost and efficiency).

3. Pressure drop in lines between regulators, and between

second stage regulator and the appliance. Pipe size will
depend on length of pipe run and total load of all
appliances.

Complete information regarding tank sizing for vaporization, rec-
ommended regulator settings, and pipe sizing is available from
most regulator manufacturers and propane gas suppliers.

Since propane gas will quickly dissolve white lead and most
standard commercial compounds, special pipe dope must be
used. Shellac-based compounds resistant to the actions of
liquefied petroleum gases such as Gasolac

®

, Stalactic

®

,

Clyde’s

®

 or John Crane

®

 are satisfactory.

Refer to the following illustration for typical propane gas instal-
lations and piping.

3/8"

1/2"

5/8"

3/4"

7/8"

1/2"

3/4"

10

730

1,700

3,200

5,300

8,300

3,200

7,500

20

500

1,100

2,200

3,700

5,800

2,200

4,200

30

400

920

2,000

2,900

4,700

1,800

4,000

40

370

850

1,700

2,700

4,100

1,600

3,700

50

330

770

1,500

2,400

3,700

1,500

3,400

60

300

700

1,300

2,200

3,300

1,300

310

80

260

610

1,200

1,900

2,900

1,200

2,600

100

220

540

1,000

1,700

2,600

1,000

2,300

125

200

490

900

1,400

2,300

900

2,100

150

190

430

830

1,300

2,100

830

1,900

175

170

400

780

1,200

1,900

770

1,700

200

160

380

730

1,100

1,800

720

1,500

Sizing Between First and Second Stage Regulator*
Maximum Propane Capacities listed are based on 2 psig pressure drop at 10 psig setting.
Capacities in 1,000 BTU/hour.

Nominal Pipe Size

Schedule 40

Tubing Size, O.D. Type L

Pipe or
Tubing

Length,

Feet

3/8"

1/2"

5/8"

3/4"

7/8"

1-1/8"

1/2"

3/4"

1"

1-1/4" 1-1/2"

10

39

92

199

329

501

935

275

567

1,071 2,205 3,307

20

26

62

131

216

346

630

189

393

732

1,496 2,299

30

21

50

107

181

277

500

152

315

590

1,212 1,858

40

19

41

90

145

233

427

129

267

504

1,039 1,559

50

18

37

79

131

198

376

114

237

448

91

1,417

60

16

35

72

121

187

340

103

217

409

834

1,275

80

13

29

62

104

155

289

89

185

346

724

1,066

100

11

26

55

90

138

255

78

162

307

630

976

125

10

24

48

81

122

224

69

146

275

567

866

150

9

21

43

72

109

202

63

132

252

511

787

200

8

19

39

66

100

187

54

112

209

439

665

250

8

17

36

60

93

172

48

100

185

390

590

Pipe or

Tubing

Length,

Feet

Nominal Pipe Size

Schedule 40

Tubing Size, O.D. Type L

Sizing Between Second Stage and Appliance Regulator*
Maximum Propane Capacities listed are based on 2 psig pressure drop at 10 psig setting.
Capacities in 1,000 BTU/hour.

Duct systems and register sizes must be properly designed for
the CFM and external static pressure rating of the furnace.
Ductwork should be designed in accordance with the recom-
mended methods of “Air Conditioning Contractors of America”
Manual D.

A duct system must be installed in accordance with Standards
of the National Board of Fire Underwriters for the Installation of
Air Conditioning, Warm Air Heating and Ventilating Systems.
Pamphlets No. 90A and 90B.