sievert gas torch

[JACK SIDEBOTHAMParticipant @jacksidebotham67303]

can anyone help with my gas torch problem?,the flame is 50/50 yellow/blue,it should be steady and all blue l believe,l set the regulator to about half open and use the knob on the torch to adjust the flame without much success,increasing the reg pressure results in the flame blowing out…starting to think there is something adrift with the burner,is there a servicing agent for sievert???,thanks all,jack.

[JACK SIDEBOTHAMParticipant @jacksidebotham67303]

[Clive Brown 1Participant @clivebrown1]

What model of torch is it and are you using propane or butane? Blowing out of the flame suggests the gas pressure is too high, whereas a yellow flame suggests the opposite. Sievert burners are usually specified for 2 bar pressure. Is the gas jet in the nozzle clear?

[JACK SIDEBOTHAMParticipant @jacksidebotham67303]

hi,the nozzle is a type 3940 on a sievert pro 86 torch body,running on propane from a 13kg bottle through an adjustable propane regulator, 0-4bar, l have the reg set to about the mid point which should be around 2 bar,l found a torch flame pattern video on you tube which shows a similar nozzle/torch combo producing a nice flame pattern that is predominately blue in colour……l have now thoroughly cleaned the nozzle and checked all the jets are clear,l will be trying it again tomorrow,but l cannot come up with an answer if it still does not work…jack.

[JasonBModerator @jasonb]

The smaller nozzles do have a cotton wool like filter inside the jet to stop "heavy ends" blocking the jet, may be worth hooking that out and checking things are really clear.

[JACK SIDEBOTHAMParticipant @jacksidebotham67303]

my nozzle is a 3940 and does not have a filter,just a a central gas jet and a ring of air jets around the central gas jet at the outer end of the nozzle,4 air inlet holes in the main body just in front of the "nut" section and a further 6 holes just behind the very outer end of the nozzle,all of these are clear,in fact,after cleaning the nozzle looks good as new,so l am of to try it again now….jack.

[Michael GilliganParticipant @michaelgilligan61133]

For convenient reference: **LINK**

https://www.cupalloys.co.uk/store/Sievert-3940-Standard-Torch-Burner-p277850794

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

This is the 2016 Sievert catalogue:

**LINK**

https://sievert.se/wp-content/uploads/2016/11/Sievert-Catalogue-UK-2016_web.pdf

it includes some good illustrations of the various flame types

MichaelG.

.

Just a thought, Jack … did you buy the burner secondhand ?

… if so, it is feasible that the jet was ‘cleaned’ enthusiastically by the seller, and is therefore oversize.

Edited By Michael Gilligan on 07/10/2022 11:42:15

[AdrianRParticipant @adrianr18614]

Has it ever worked? I inherited a set of burners. One looked like new even though it was many decades old, it had the same problem as yours, I found out why, the jet was badly drilled. I have tried opening it up but no joy.

I tried to get a new jet but could not find a supplier, in the end it went back in the box, I will buy a new burner if I ever need that size.

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