iSi North America AMV8 User Manual

20

This unit is configured for natural gas.  The appropriate
manufacturer’s propane gas conversion kit, must be applied for
propane gas installations.  Refer to the “Propane Gas and/or
High Altitude Installations” section for details.

Contact your distributor for a tabular listing of appropriate
manufacturer’s kits for propane gas and/or high altitude
installations.  The indicated kits must be used to insure safe and
proper furnace operation.  All conversions must be performed by
a qualified installer, or service agency.

When sizing a trunk line, be sure to include all appliances which
will operate simultaneously when sizing a trunk line.

The gas piping supplying the furnace must be properly sized based
on the gas flow required, specific gravity of the gas, and length of
the run.  The gas line installation must comply with local codes, or
in their absence, with the latest edition of the National Fuel Gas
Code, NFPA 54/ANSI Z223.1.

Length of

Nominal Black  Pipe Size

Pipe in Feet

1/2"

3/4"

1"

1 1/4"

1 1/2"

10

132

278

520

1050

1600

20

92

190

350

730

1100

30

73

152

285

590

980

40

63

130

245

500

760

50

56

115

215

440

670

60

50

105

195

400

610

70

46

96

180

370

560

80

43

90

170

350

530

90

40

84

160

320

490

100

38

79

150

305

460

(Pressure 0.5 psig or less and pressure drop of 0.3" W.C.; Based on
0.60 Specific Gravity Gas)

CFH =

BTUH Furnace Input   
Heating Value of  Gas (BTU/Cubic Foot)

To connect the furnace to the building’s gas piping, the installer
must supply a ground joint union, drip leg, manual shutoff valve,
and line and fittings to connect to gas valve.  In some cases, the
installer may also need to supply a transition piece from 1/2" pipe
to a larger pipe size.

The following stipulations apply when connecting gas piping.
Refer to Figure 16 for typical gas line connections to the furnace.

• Use black iron or steel pipe and fittings for the building

piping.

• Use pipe joint compound on male threads only.  Pipe joint

compound must be resistant to the action of the fuel used.

• Use ground joint unions.
• Install a drip leg to trap dirt and moisture before it can enter

the gas valve.  The drip leg must be a minimum of three
inches long.

• Install a 1/8" NPT pipe plug fitting, accessible for test gage

connection, immediately upstream of the gas supply
connection to the furnace.

• Use two pipe wrenches when making connection to the

gas valve to keep it from turning.  The orientation of the gas
valve on the manifold must be maintained as shipped from
the factory.

• Install a manual shutoff valve between the gas meter and

unit within six feet of the unit.  If a union is installed, the
union must be downstream of the manual shutoff valve,
between the shutoff valve and the furnace.

• Tighten all joints securely.
• Connect the furnace to the building piping by one of the

following methods:

–

Rigid metallic pipe and fittings.

–

Semi-rigid metallic tubing and metallic fittings.

Aluminum alloy tubing must not be used in exterior
locations.

–

Use listed gas appliance connectors in accordance

with their instructions.  Connectors must be fully in
the same room as the furnace.

–

Protect connectors and semi-rigid tubing against

physical and thermal damage when installed.  Ensure
aluminum-alloy tubing and connectors are coated to
protect against external corrosion when in contact with
masonry, plaster, or insulation, or subjected to
repeated wetting by liquids such as water (except rain
water), detergents, or sewage.

``

Location of Manual Valve
(Installed Ahead of Ground
Joint Pipe Union)

Height Required
By Local Code

Ground Joint Pipe Union
To Be Installed Ahead Of 
Gas Valve

Drip Leg

Reducing Coupling
1/2" x 1/8" with 1/8"
Pipe Plug To Measure
Line Gas Pressure