Product Overview/Installation | 4020 Nozzle-Mix Pilot Tip
"HP" AND "CB" HIGH PRESSURE PILOT (use in place of premix pilot)
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 holes. Use a 5000/6000 volt transformer for spark ignition. 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.
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 1. Before installing, make sure the air and gas lines are free of dirt and scale by blowing out each fitting & section of pipe before and after installing it, (but don’t put pressure on regula tors and solenoid). In-line filters will help prevent pilot plugging.
ADDITIONAL PILOT INSTALLATION TIPS
- An arrow with the air flow direction is stamped on the body of 4020 pilot tips. The pilot must be installed in the correct direction or it will not work correctly. - The preferred location for pilot tips (and UV cells) is on the top or side of a burner so that scale, dirt, and refractory crumbs cannot fall into it. - Short run impulse lines for pilot systems should be 1/4 " thin wall tubing. 304 stainless tube 1/4 " OD x .035" wall is a good choice. Copper tubing can also be used, but is more susceptible to kinking. - Avoid stressing and distorting valves and regulators, small pilot regulators may be easily damaged by incorrect use of wrenches. Put your wrench on the end nearest that pipe that it's being threaded into.
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- Undersized piping and plugged lines are common causes of pilot problems. Avoid corrugated connectors and hoses, they cause more pressure loss than regular pipe and fittings. Tubing has ½ the area, and 4 times the pressure loss of the same “size” pipe. It’s OK to use tubing that has as much flow area as pipe. (Example: use 7/8 "OD × .045"wall tubing in place of 3/4 " pipe)
compressed air
dirt
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!
- Avoid thread dope or Teflon tape applied over the ends of pipe thread, it can break loose and plug pilot tips.
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.
2 threads
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Bulletin 4020 Page 3
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