Brazing

[alan ord 2Participant @alanord2]

I have been brazing a number of parts for my 5" Pansy loco today and 4 or 5 times my Sievert Pro 86 torch kept flaming out. I have a regulator attached to the bottle but not sure what might be causing it. Can anybody provide me with some advise as to what is going wrong.

Thanks,

Alan.

[alan ord 2Participant @alanord2]

[KWILParticipant @kwil]

Flaming out? You must be starving it of air?

[Keith HaleParticipant @keithhale68713]

Alan. If your torch is flaming out there are two possible reasons. The gas pressure is too high and the speed of the gas flow is exceeding the speed at which the gas burns. You could be simply blowing the flame off the end of the burner.
Or you are starving the gas of air. In this case change the burner to a cyclone type.
For more information see the website cupalloys.co.uk

[julian atkinsParticipant @julianatkins58923]

Hi Alan,

I would suggest you are getting the torch too close to the job.

I know you are not yet onto the boiler which discounts other possibilities!

As another possibility can you lift easily your propane bottle? If so, it may be getting rather empty.

Cheers,

Julian

[alan ord 2Participant @alanord2]

Thanks for the feedback, it is appreciated. I think Cup Alloys may have the right answer as I fully opened the regulator anticipating to regulate the flame by the nozzle adjustment knob. I will try again with the regulator closed off a little more.

Julian, good to hear from you, next time I will try keeping the flame further back from the job. It won't be the lack of gas in the bottle, or it shouldn't be, as it is a new bottle. But your comment is dually logged into the memory bank.

Thanks everybody,

Alan.

[richardandtracyParticipant @richardandtracy]

If using Butane as the fuel, how warm is your workshop?

If the temp is too low, the butane may not be evaporating fast enough to keep the pressure up. As the gas evaporates, the gas takes energy from the remaining liquid and can cool it down to the point the butane ceases to evaporate. I remember a vivid case when my dad was on exercise in the 1970's in Germany, in winter (-20C) & the only way to brew tea was to use a 2 burner stove. The camping gaz bottle was on one burner, and the kettle on the other. That way the gas bottle stayed warm enough to supply both burners.

Just another possibility to consider if the demand is HUGE and bottle fairly small.

Regards,

Richard.

[not done it yetParticipant @notdoneityet]

will try again with the regulator closed off a little more.

That is likely the reason, not quite what Cup meant, I think.

If you are opening up the regulator to the point that it is not actually regulating, the gas pressure from the bottle will vary with temperature, leading to your constriction at the burner seeing a different pressure drop across itself. Maintaining a constant pressure before you burner valve is necessary for consistent control at the burner.

[Keith HaleParticipant @keithhale68713]

????????

Sievert regulators cannot be opened to the point that they do not regulate the presuure of gas being fed to a burner.

Regulator 3091 is a "fixed" regulator factory set to deliver 2 bar.

Regulator 3063 is a " variable" regulator that can be adjusted manually to deliver between 1 – 4 bar

Regulator DN20056X is a variable regulator that can be manually adjusted between 0 – 4 bar.

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The 3000 range of burners is designed to run at 2 bar

The 2000 range is designed to run at between 2 and 4 bar dependent on the heating effect required. Increased pressure = increased heat output.

Trying to run a 2000 burner at 4 bar results in the flame being blown off the end of the burner. Trying to reduce the heating effect of a 2000 series burner by reducing the presure below 2 bar causes the flame to withdraw into the nozzle. This can damage the injector not least by causing it to block with the soot formed by incomplete combustion of the gas.

Keith

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