Raypak AVIA 264A - Gas Orifice and Burner Components; Orifice Removal and Selection; Igniter and Burner Removal

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Orice Removal
1. Locate and close the external manual shutoff valve.
2. Loosen the external gas union.
3. Locate and remove jacket top.
4. Locate and remove the four (4) bolts & nuts holding
the gas orifice in place. See Figure 65.
5. Carefully remove the gas orifice and do not misplace
the O-rings attached to the flanges.
6. Inspect and/or replace the orifice with the correct
size.
GAS ORIFICE
BRACKET
O-RING
Figure 65. Orice Location
Gas and Orice Selection
The gas orice and the air orice MUST match to attain
the correct air/fuel ratio. The orices are matched when
the number of pockets on the side of the gas orice is the
same as the number of notches on the edge of the air
orice. The orice selection is based on elevation, not on
the fuel used. See Table R.
The gas orice is located on the gas train, between the gas
valve and the combustion blower. The air orice is located
on the inlet side of the combustion blower.
NOTE: Gas orices for propane gas have a black oxide
nish.
Figure 66. Gas Orice
Pockets /
Notches
Model Gas Type Finish
1 264
Natural None
2 404
1 264
Propane Black
2 404
Table R. Orice Usage
Igniter Removal.
1. Remove top cover.
2. Disconnect spark cable from igniter.
3. Use M10 socket, remove the two nuts holding the
igniter.
4. Carefully remove igniter and gasket.
5. When replacing igniter, be sure to add a new gasket
when installing igniter.
.15 +/- .01
Figure 67. Igniter
Burner Removal
1. See “Combustion Blower Removal” steps below.
Must remove blower to reach the burner.
2. Once the blower is removed. Use an M10 socket to
remove (16) nuts holding down the burner.
3. Be sure to install a new gasket before installing the
burner.