Wolf OG30, Technical & Service Manual

Page: 27 / 54

Theory of Operation
Outdoor Grill (OG) Series
3-5
#814144 - Revision A - July, 2009
Simple Theory of Operation:
Gas arrives at the appliance through
pipes in the form of natural gas or liquid
propane gas. This gas supply can be
from a local utility source or a tank
source.
A gas pressure regulator on the appliance
is connected to the gas supply. The reg-
ulator maintains the gas pressure in the
appliance at a given point below the
incoming supply gas pressure.
(See Figure 3-3)
The gas passes through the regulator
and is piped to a gas valve. This valve
can be opened in varying amounts to
allow more or less gas to pass through.
This is how the size of the flame is
adjusted.
(See Figure 3-4)
NOTE: It is necessary to push the con-
trol knob and valve shaft in to turn the
control knob and open the valve. This
action on the OG appliances also ener-
gizes the glow igniter (when connected to
electricity), which will ignite the gas.
After the valve, the gas flows through a
gas orifice, which has an opening of very
small diameter. Because of the small
diameter of the opening and the gas
pressure behind it, the gas exits the ori-
fice at a high velocity. This high velocity
stream of gas causes a drop in pressure
around itself. The low pressure around
the stream of gas draws air in through the
shutter, referred to as "primary air", with it
into the venturi tube. (See Figure 3-5)
(Continued on next page)
G A S
Figure 3-3. Gas Pressure Regulator
Regulator
G A S
G A S
Figure 3-4. Gas Valve
Regulator
Control
Knob
Valve
G A S
G A S
PR
IMA
RY A
IR
Figure 3-5. Gas Orifice and Shutter
Regulator
Control
Knob
Orifice
Valve
Shutter Venturi