maxon tube o flame iom

�CORPORATIONMUNCIE, INDIANA, USAINDUSTRIAL COMBUSTION EQUIPMENT AND VALVES

Maxon practices a policy of continuous product improvement. It reserves the right to alter specifications without prior notice.

Gas supply piping must be large enough tomaintain the required fuel pressures cataloged for theparticular burner size used with burner operating atfull rated capacity.

Anything more than minimal distance or pipingturns may necessitate oversizing piping runs to keeppressure drops within acceptable ranges.

Inlet pipe leading to any burner should be at leastfour pipe diameters in length. If multiple burners arefed from a single gas train, care should be taken tominimize pressure drop and give maximum uniformity.

Clean fuel lines are essential to prevent blockageof pipe train components or burner gas ports.

Main Shut-Off Cock should be upstream of boththe main gas regulator and pilot line take-off. Use it toshut off fuel to both pilot and main burner during shut-down periods of more than a few hours.

The fuel throttling valve contained within a Maxonburner is not intended for tight shut-off.

Main gas regulator is essential to maintain auniform system supply pressure. If one pipe trainsupplies multiple burners, provide a separate regula-tor in the branch leading to each burner system.

Size the regulator for full system capacity at therequired pressure, carefully considering pipe trainlosses. Follow the instructions attached to the regula-tor during installation and be sure to remove anyshipping pin or block.

Pilot take-off should be upstream of the main gasregulator, but downstream of the main gas cock. Itshould normally include its own pilot gas regulator, asolenoid valve and shut-off cock. A pilot adjustableorifice at the pilot inlet simplifies adjustment.

Pilot piping must be large enough to provide forthe full flow and pressures shown in the catalog foryour particular burner size.

The 3/8" pilot connection of the Series “67” TUBE-O-FLAME® Burner is adequate for the pilot gas flowsshown, but care must be taken to assure that therequired gas pressure is available at pilot inlet. Toavoid excessive drop through solenoid and upstreamvalves and cocks, follow these guidelines:

Page 2200-S-1Series “67” TUBE-O-FLAME® Gas Burners

Installation Instructions

General InstructionsImportant: Do not discard packing material untilall loose items are accounted for.

To prevent damage in transit, the spark ignitor,mounting ring, flame rod and connecting linkagecomponents may be packed separately and shippedloose with your new Maxon TUBE-O-FLAME® Burner.

The burner itself is normally only a part of yourcomplete combustion system. Additional pipe trainaccessories and control components will be requiredfor a complete system installation. The sketch belowshows a typical gas train as might be used with aSeries “67” TUBE-O-FLAME® gas fired burner.

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Piping Layout as sometimes required byinsurance and standards groups

Block and Bleed gas train arrangement illustratedwith Series “67” TUBE-O-FLAME® Burner

TUBE-O-FLAME® Burner provides the air supply(unless it is an LB version, which requires a separatecombustion air blower). It also serves as a fuel flowcontrol and fuel/air mixing device.

Burner should not be exposed to direct radiantheat or positioned where it might draw in inert gases.If such conditions exist, consider filters, relocation,and/or use of the LB version and external air supply.

Electrical service must match the voltage, phase,and cycle of all electrical system components and becompatible with burner nameplate ratings. Insure thatall normal control safeguards are satisfied. Combus-tion air blower should continue to run after shutdownto allow burner to cool.

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�CORPORATIONMUNCIE, INDIANA, USA INDUSTRIAL COMBUSTION EQUIPMENT AND VALVES


200-S-2 Series “67” TUBE-O-FLAME® Gas Burners


Suggested supporting arrangementsFuel Shut-Off Valves (when properly connected toa control system) shut the fuel supply off when ahazardous operating condition is sensed. Manualreset valves require operator attendance each timethe system is started up (or restarted after a trip-out).Motorized shut-off valves permit automatic start orrestart when used with an appropriate control system.

Test connections are essential for burner adjust-ment. They should be provided immediately down-stream of the regulator and are included in the burneritself. Test connections must be plugged exceptwhen readings are being taken.

Exhaust stack dampers are necessary to theproper operation of an immersion tube burner system.They should be lockable, suitable for 1000ºF anddesigned to prevent full stack closure.

Horizontal mounting is preferred. Most manufac-turers’ control motors require operating shaft in ahorizontal plane.

Burner mounting requires four studs and a flatmounting surface perfectly centered on the firing tube.Burner can be mounted directly on tank wall usingfour welded studs, but the more common practiceutilizes an optional mounting ring (complete withstuds) welded to tank wall, end of tube, or othermounting surface. If the application calls for position-ing the burner in other than its normal upright position,be sure to align studs appropriately.

After placing burner in position over studs, add lockwashers and nuts, then draw up all four hand-tightonly. Check that burner is seated evenly around theflange, filling any gaps to prevent air leakage, thentighten all nuts firmly.

For proper performance of any burner, air inlet andmotor should be surrounded by clean, fresh, cool air.

Burner and pipe manifold support may berequired to support weight of the burner and con-nected pipe train components. Air control motors, inparticular, require additional support. Maxon connect-ing base and linkage assemblies are designed toposition the control motors to work with the burner,not to support their weight.

The Series “67” TUBE-O-FLAME® Burner mayrequire external auxiliary support provided by theuser. The support configuration may be similar to theleg support or knee bracket support illustrated.

Additional burner support may be required inconjunction with a stiffener plate when mountingTUBE-O-FLAME® Burner (weighing 100-350 pounds)onto tube or thin tank walls.

Exhaust ConsiderationsImmersion tubes are usually vented to the outdoors,

except for those in highly ventilated areas such as aplating room with continuous high volume exhaust. Anexhaust fan may be required if the building is undernegative pressure. Exhaust is normally diluted to avoidthe need for high temperature fans, but adequate make-up air must be available.

This diluting can be done with an open tee installedin a vertical run (or in a horizontal run with the openend down), but such a system mixes slowly.

An adjustable hood (shown in sketch below) offersmuch better performance. In all cases, care must betaken that all products of combustion are exhaustedfrom the building.

An exhaust stack damper must be used, suit-able for 1000°F, and designed to prevent fullstack closure.



Series “67” TUBE-O-FLAME® Gas Burners Page 2200-S-3


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Protective covers for burner should be added inthe field if exposure to dripping condensate, splashingflux, exhaust steam, etc. is unavoidable.

Sketches below illustrate some possible arrange-ments. Any cover used should be removable toprovide access to burner and should not interfere withcontrol linkage motion or observation port viewing.

Field conversion from a flame rod version to a UVscanner version and vice versa may require additionalparts in the burner. Contact Maxon for requirements.

Alternate fuels may require correction of supplypressures.

If TUBE-O-FLAME® Burner is equipped withMaxon Hi/Lo Control Motor, low-fire start wiring canbe accomplished as shown in the sketch below.

Maxon assumes no responsibility for the use ormisuse of the layouts shown. Specific pipingand wiring diagrams should always be submit-ted to the appropriate agencies for approval oneach application.

Multi-burner installations require special consid-erations if supplied by a common pipe train and/or airsupply. Air and Gas Balancing Valves should beused for improved heating uniformity; Gas Swing-Check Valves should be installed as close as pos-sible to each burner inlet for dependable lightoff (gasmanifold may otherwise act as a reservoir, preventinglightoff during trial-for-ignition period).

Control system's circuitry must not allow mainFuel Shut-Off Valve to be opened unless combustionair is on, and must de-energize valve upon loss ofcombustion air pressure, along with the other usualsystem interlocks. Motor starter is to be interlockedwith valve, whether or not a combustion air pressureswitch is used.

WARNING: Welding of burner flange to astiffener plate or firing tube may cause warpageof burner flange and require additional sealmaterial to prevent leakage.

Flame sensing can be accomplished by eitherflame rod or UV scanner. When UV scanner is used,it should be kept as close to burner as feasible. Donot use cooling air to scanner port: sighting isthrough gas cavity. Heat block, if used, may affectsignal strength with some brands of scanners.



Initial start-up adjustment should only beaccomplished during a “manual” burnercontrol mode.

5. Start all system-related fans and blowers.Check for proper motor rotation and impellerdirection. Verify that all control interlocks areworking. Allow air handling equipment to run foradequate purge of your manifolds and immersiontubes. With main gas shut off, manually advanceTUBE-O-FLAME® Burner's operating crank to“high fire” position so that air only flows throughburner and firing tube.

CAUTION: Do not by-pass control panel timerstypically controlling sequential operations.

Series “67”TUBE-O-FLAME®

Burners

6. Determine static condition of tube (draft orsuction) and verify differential air pressure atburner backplate air test port.

Measure your air pressure reading withmanometer connected between the burner's airpressure test port and atmosphere with the burnerat “high fire” position, fuel valves closed, and allair handling systems running.

Series “67” TUBE-O-FLAME® Gas Burners

Start-Up Instructions

Read complete instructions before proceeding,and familiarize yourself with all the system's equip-ment components. Verify that your equipment hasbeen installed in accordance with the original manu-facturer's current instructions.

CAUTION: Initial adjustment and light-offshould be undertaken only by trained andexperienced personnel familiar with combus-tion systems, with control/safety circuitry, andwith knowledge of the overall installation.Instructions provided by the company and/orindividuals responsible for the manufactureand/or overall installation of complete systemincorporating Maxon burners take precedenceover these provided by Maxon. If Maxoninstructions conflict with any codes or regula-tions, contact Maxon Corporation beforeattempting start-up.

For initial TUBE-O-FLAME® Burner start-up:1. Close all burner fuel valves and cocks. Make

preliminary adjustments to fuel gas regulators.Remove pilot and main gas regulators' adjustingscrew covers. Turn adjusting screw down (clock-wise) to approximately mid-position. Close pilotgas adjustable orifice screw by turning in clock-wise until it stops. (Do not over-tighten.) Thenback out the adjustable orifice (counter-clockwise)approximately 2-3 turns.

2. Check all electric circuitry. Verify that all controldevices and interlocks are operable and function-ing within their respective settings/ranges. Besure all air and gas manifolds are tight and thattest ports are plugged if not being used.

3. Check that the immersion tube stack damperis properly positioned and locked into operatingposition.

4. Disconnect the automatic control motor'slinkage from your TUBE-O-FLAME® Burner'soperating crank arm by loosening the controlmotor's connecting rod from the burner's togglelinkage.

Page 2200-S-4



Page 2200-S-5Series “67” TUBE-O-FLAME® Burners


11. Open main and pilot gas cocks, then attemptspark ignition to light pilot while slowly turningpilot gas regulator clockwise and/or adjustableorifice screw counter-clockwise to increase fuelflow. Repeat procedure as necessary until pilotignites, as air might have to be bled out of fuelsupply lines before reliable pilot flame is estab-lished. Pilot gas regulator should normally be setfor as low a pressure as possible, using fulleropening of pilot gas adjustable orifice (if used).

12. After ignition, adjust pilot flame for good stableflame shape. A rule of thumb is that any pilot overa tennis ball size is probably too large. Thisassumes you have visual access to the pilotflame. If this is not possible, then adjust pilot togive the strongest and most stable flame signalthrough your flame safety circuit. This signalstrength can be read with a micro-amp meter. Thesignal strength (or range) will be determined bythe specific type of flame safeguard instrumentyou have with your burner system.

13. Re-check pilot ignition by closing pilot gas cockor otherwise causing pilot outage. Re-light andrefine pilot gas adjustment as necessary to getignition within a second or two. The flame safe-guard relays should now power your main fuelShut-Off Valve(s).

CAUTION: After completing steps above, re-check all interlocking safety components andcircuitry to prove that they are properly in-stalled, correctly set, and fully operational. If indoubt, shut the system down, close pilot cockand contact responsible individual beforeproceeding further.

14. Establish main flame. With burner at low fireposition, back out main gas pressure regulatoradjusting screw (counter-clockwise) to get lowestoutlet pressure possible. Open all manual fuelshut-off valves (automatic fuel shut-off valveshould already be open) so gas flows to burnerinlet. There should be little, if any, change inflame appearance. Turn main regulator adjust-ing screw in (clockwise) to obtain outlet pressureof about 4"-6" wc higher than combustion cham-ber pressure (2"-4" wc for propane, considerablyhigher for some LB versions). Main flame shouldnow appear larger than pilot-only flame.

Record air test port reading. Chart below showsnormal balanced tube static condition readings.

If your reading exceeds these normal readings,you have a back pressure in your tube.

If your readings are lower than the normalbalanced readings, you have an exhaust suctionin your tube.

Excessive suction can cause chugging andimplies hot combustion products are being drawnout of the tube too fast, reducing thermal transferefficiency. High tube suction also may affectdifferential gas pressure settings. Too high of asuction may lower inlet gas pressures so that lowgas pressure switches cannot be adjusted.

Excessive back pressure can cause smokeand may restrict firing capacity of burner.

NOTE: The differential air pressure setting deter-mines the burner's capacity and performance capabili-ties.

7. Adjust exhaust fan and/or stack damper tocreate burner air pressure test port readings asclose as possible to those shown for normalbalanced conditions to maximize system's thermaltransfer efficiency.

NOTICE: Burner performance can be drasticallyaffected by tube configuration and staticconditions within tube created by exhaust fansand dampers in exhaust stack.

8. Determine the required differential gas pres-sure using this differential air pressure readingobtained from step 6. High fire pressures areprovided in Maxon product line catalog literatureand/or read data stamped into burner nameplate.

9. Verify that spark ignitor is properly positionedand lines up with the appropriate dimensionsrequired for your specific burner. (Refer to appro-priate Maxon catalog specification table.) Checkthat spark ignitor arcs at the end of your properlypositioned ignitor.

10. Return burner control valve/crank to low fireposition when purge of system is complete.

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17. Re-check differential gas pressure with unit atoperating temperature. Refine high fire setting ifnecessary, considering differential pressure,flame length, and appearance. Dust or contami-nants in the air stream may affect flame appear-ance.

18. Plug all test connections not in use to avoiddangerous fuel leakage. Replace equipmentcover caps and tighten linkage screws.

19. Check out overall system operation by cyclingthrough light-off at minimum, interrupting pilot,and allowing temperature control system to cycleburner from minimum to maximum and return.NOTE: Typical gas firing control sequence forMaxon burner is provided only as a guide. Instruc-tions provided by complete system manufacturerincorporating Maxon burners take precedence.

For gas firing Series “67”TUBE-O-FLAME® Burner

Light-off: Shut-down:1. Close cocks, shut-off valve(s) 1. Close main &2. Verify burner at low fire pilot gas cocks3. Start recirculating/exhaust fans 2. Keep combustion4. Start burner blower air blower running5. Purge at least 4 air changes after shut-down long6. Open pilot & main gas cocks enough to allow

burner to cool

Recheck all safety system interlocks for propersetting and operation.

WARNING: Test every UV installation for danger-ous spark excitation from ignitors and other pos-sible sources of direct or reflected UV radiation.Use only gas-tight scanner connections.

20. Before system is placed into full service,instruct operator personnel on proper start-upoperation with shut-down of system, establishingwritten instructions for their future reference.

Page 2200-S-6 Series “67” TUBE-O-FLAME® Gas Burners


15. Establish high fire setting by slowly movingburner crank toward high fire position whileobserving gas pressure at burner gas test con-nection. Refine main gas regulator adjustment asnecessary to provide correct differential gaspressure at high fire. If pressure cannot beadjusted low enough, a different regulator orregulator spring may be necessary, or a limitingorifice valve (such as Maxon's Series “BV”)should be added. Do not, however, exceed 4" wcpressure drop between regulator outlet andburner inlet.

CAUTION: If burner(s) go out, close shut-offvalve or shut main gas cock at once. Return tominimum setting, re-light pilots if necessary,then turn main gas on again. Check carefullythat every burner is lit before proceeding.

Cycle burner from minimum to maximumand refine adjustment, if necessary.

For operation with interrupted pilot (asrecommended), shut off pilots and cycle burnerfrom minimum to maximum and back severaltimes to verify the flame is maintained.

16. When burner performance is satisfactory andstable throughout the firing range, reconnectlinkage to control motor.

Control linkage travel must be such that burnercrank is moved throughout its complete travel, orcataloged capacities and turndowns will not beachieved.

If less than full-rated burner capacity is re-quired, linkage can be adjusted to limit maximumoutput. With interrupted pilot, it may be neces-sary to set control for somewhat higher thanminimum burner setting to permit hold-in of flamedetection system without pilot.

CAUTION: Internal drive mechanism within thecontrol motor may be damaged if linkage isadjusted so as to cause binding with burner inhigh or low fire position.

maxon tube o flame iom

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