Installation | 4020 Nozzle-Mix Pilot Tip
holes. Use a 5000/6000 volt transformer for spark ignition.
"HP" and "CB" High Pressure Pilot (use in place of premix pilot)
6. Be certain the flame detection UV scanner on the burner is positioned to prevent proving a pilot flame that is inadequate for main flame ignition. 7. Honeywell UV scanners can monitor the pilot flame when mounted on the back of the tip if set at 25% or more of its rat- ed capacity. However, main flame monitoring in this position is not reliable and not recommended.
The "HP" version is used in place of premix pilot assemblies. It features a built in orifice that raises the air pressure, allowing the use of a cross connected regulator. The 4020-HP has been designed so that when the air and gas pressures are equal at the pilot tip, the flame will burn with ap- proximately 100% excess fuel which is within the 4020’s rich stability limit. This makes it very easy to set the pilot when using a cross connected ratio regulator. In many cases, the gas limit- ing orifice valve can be left fully open, allowing the regulator to maintain the proper air/fuel ratio for pilot use. The pilot flame is visible from the rear through an observation port if installed on an air inlet tee. Although the length of the flame can not be judged fully, it is still useful to use the observation port for setting up the pilot, and monitoring performance. An optional air valve is available for the -0 size which includes an orifice and a pressure tap that allows the pilot to be cross connected like a "HP". At equal air and gas pressures on a -0 "HP" setup, the ratio will be very close to the rich stability limit. (See the capacity chart for the correct gas pressure at 100% excess fuel.) The 4020-CB has extra air passages that cool the body of the tip. The cooling air also effectively lowers the excess fuel rating to 50%, shortens the flame, and increases the excess air limit. The "CB" is a good choice for use as a small burner. INSTALLATION Before installing, make sure the air and gas lines are free of dirt and scale. In-line filters will help prevent pilot plugging.
Lighting "LP"
1. Close all fuel supply lines.
2. Set the burner to the conditions where the pilot will normally be started (low fire lighting condition). Set the air pressure at the tip.
3. Supply an ignition source to the spark plug and open the gas until the pilot tip lights.
4. Set the gas so that the pilot flame is large enough to light the burner reliably (gas pressures 2-6 times higher than the air pressure are recommended).
Lighting "HP"
1. Close all fuel supply lines.
2. Set the burner to the conditions where the pilot will normally be started (low fire lighting condition). Set the air pressure at the tip to 6 to 12 osi. 3. If a cross connected ratio regulator is installed, open the gas limiting orifice valve to 100% open. If there is no cross con- nected ratio regulator set the gas pressure so that it equals the air pressure (see capacity chart).
2. Apply anti-seize compound to the threads, and screw the tip into the pilot boss until hand tight. Do not over tighten the tip!
4. Supply an ignition source to the spark plug and open the main pilot gas valve.
3. Connect pilot air and gas lines to sources upstream of all main burner control valves. Use pipe unions on the air and gas lines close to the tip. The gas valve and gas supply piping should be larger than the fitting on the tip (except in the -0 size, see accessories table for details). 4. If possible use a cross connected pilot regulator on the gas line (except the "LP"). Although the ratio stability limits are very wide on the 4020, a ratio regulator assures that the pilot will run consistently if the air pressure varies. 5. Install the spark plug in whichever port is convenient and block the other spark port with the provided pipe plug. In the -6 and -7 sizes the spark plug must be centered between air
5. Make flame adjustments using the gas limiting orifice valve or air valve, if necessary. Set the gas so that the pilot flame is large enough to light the burner reliably.
Bulletin 4020 Page 4
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