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TABLE 9A—PRESSURE REGULATOR SPECIFICATION PRESSURES IN kPa.
I
TYPE
OF GAS
MODEL
NAT
VS821A
LP
NAT
LP
CHECK SAFETY SHUTDOWN PERFORMANCE
FIRE OR EXPLOSION HAZARD
CAN CAUSE PROPERTY DAMAGE, SEVERE
Performthe safety shutdowntest any time work
FIRE OR EXPLOSION HAZARD
CAN CAUSE PROPERTY DAMAGE, SEVERE
INJURY, OR DEATH
Improper cleaning or reassembly may cause gas
leakage. When cleaning, ensure that control is
reassembled properly and perform gas leak test.
Regular preventive maintenance is important in appli-
cations that place a heavy load on system controls, such as
in the commercial cooking and agricultural and industrial
industries because:
In many such applications, particularly commercial
cooking, the equipment operates 100,000-200,000
cycles per year. Such heavy cycling can wear out the
gas control in one to two years.
Exposure to water, dirt, chemicals and heat can
damage the gas control and shut down the control
system.
I
I
NOMINAL INLET
STEP
PRESSURE RANGE
1.2-1.7
2.9-3.9
1.2-1.7
2.9-3.9
OUTLET PRESSURE
NOMINAL
FACTORY SETTING
FULL RATE
—
0.9
—
2.7
0.2
0.9
0.5
2.7
I. Place gas control knob in PILOT position. Main
burner should go off and pilot should remain lit.
2. Extinguish pilot flame. Pilot gas flow should stop
within 2-1/2 minutes. Safety shutoff of pilot gas proves
complete shutdown since safety shutoff valve blocks flow
of gas to main burner and pilot.
3. Relight pilot burner and operate system through one
complete cycle to make sure all controls operate properly.
The maintenance program should include regular
checkout of the gas control as outlined under STARTUP
AND CHECKOUT on page 9, and the control system as
described in the appliance manufacturer's literature.
Maintenance frequency must be determined individu-
ally for each application. Some considerations are:
Cycling" frequenqv. Appliances that may cycle
100,0OOtimes annually should be checked monthly.
Intermittent use. Appliances that are used season-
ally should be checked before shutdown and again
before the next use.
Consequence of unexpected shutdown. Where the
cost of an unexpected shutdown would be high, the
system should be checked more often.
Dusty, wet or corrosive environment. Since these
environments can cause the gas control to deterio-
rate more rapidly, the system should be checked
more often.
The gas control should be replaced if:
It does not perform properly on checkout or trou-
bleshooting.
The gas control knob is hard to turn or push down, or
it fails to pop back up when released.
The control is likely to have operated for more than
200,000 cycles.
11
RANGE
STEP
FULL RATE
—
0.7-1.2
—
2.0-3.0
None
0.7-1.2
2.0-3.0
None
60-2019—7
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