L.B. White I-34 Infraconic Pilot Ignition - Manual (Page 17)

OPERATION AND SETTING OF PRESSURE
VALVE AND PILOT RELIGHT VALVE
All infraconic pilot ignition radiant heaters use two control
components. These are the main burner pressure valve
and pilot relight valve.
OPERATION
The regulator on the zone control panel supplies constant
20 in. W.C. pressure to the pilot light through the pilot
relight valve on the heater. The pilot relight valve allows gas
to flow to the pilot at the range of 20 in. W.C. to 65 in. W.C.
When the building controller calls for heat, the solenoid on
the zone panel opens, supplying high pressure gas to the
heater.
As pressure increases up to 45 in. W.C. the pressure valve
opens and supplies gas to the burner cones. The pilot lights
the burner. When pressure increases to 65 in. W.C. the
pilot relight valve closes, stopping the flow of gas to the
pilot. The main burner pressure valve continues to open
until 5 psig is being fed to the burner cones.
When the temperature is satisfied, the building controller
shuts off power to the zone panel. Pressure decreases to
the heater. The main burner pressure valve starts to close.
At 65 in. W.C. the pilot relight valve opens, supplying gas to
the pilot. The main burner flame lights the pilot before the
burner shuts down.
SETTING
After significant use, the pilot relight valve and main burner
pressure valve may require checking to ensure proper
operation. This procedure may require assistance of
another person.
INITIAL PREPARATION
- Close fuel supply to zone panel.
- Clean the heater thoroughly, including pilot and
main burner orifices.
- Connect an accurate 0-100 in. W.C. pressure gauge
to panel.
- Remove spring from regulator on zone panel.
Re p l a c e i t w i t h s p r i n g t h a t a l l ow s p r e s s u r e
adjustment range to 65 in. W.C. (available from L.B.
White., part #21876)
- Open fuel supply and light pilot.
PROCEDURE
A. Main Burner Pressure Valve
- O b s e r ve p r e s s u r e g a u g e a n d b u r n e r w h e n
conducting test.
- Slowly increase pressure to the heater using the
zone panel regulator.
- The burner should light when pressure to valve
reaches 45 in. W.C.
- If pressure valve opens above 45 in. W.C., remove
its cap and slowly turn the adjusting screw counter-
clockwise.
- If main burner pressure valve opens below 45 in.
W.C., slowly turn its adjusting screw clockwise.
B. Pilot Relight Valve
- Observe pressure gauge and pilot flame when
conducting this test.
- If relight valve closes above 65 in. W.C., remove its
cap and slowly turn, adjusting screw counter-
clockwise.
- If relight valve closes below 65 in. W.C., remove its
cap and slowly turn adjusting screw clockwise.
COMPLETION
- Remove test spring from regulator on zone panel
and install original spring.
- Light heater and set pilot pressure to 20 in. W.C. at
zone panel regulator.
- Shut off gas supply.
- Remove gauge.
17
PILOT RE-LIGHT VALVE
COMPRESSION NUT
INJECTOR TUBE
SCREW
PRESSURE VALVE
ADAPTER
PRESSURE
VALVE
PILOT SAFETY
CONTROL VALVE
ADAPTER
ADAPTER
PILOT RELIGHT VALVE
1. Remove thermocouple from pilot safety control valve.
2. Loosen pilot tube compression nut at outlet of pilot
re-light valve.
3. Loosen injector tube screw and pull control assembly
from heater.
4. Remove pressure valve from pilot safety control valve.
5. Remove pilot safety control from adapter at pilot
relight valve inlet.
6. Remove adapters from relight valve inlet and outlet.
FIG. 17