Brett

Hi Neil, yes both those are possibilities. It will take me a couple of weeks to install an inline valve and re-test, and then come back to the forum with success or failure. Thanks for all the suggestions.

Thanks Babs. Fired once to cone 6 previously but struggled, so new burners and regulator. I start with a small burner.

Thanks Bill - I will put a hand operating valve upstream of the burner as you suggest, and take into account all the other information supplied by you and others. Thanks again!

Hi Babs, You can see in the image posted with the arrow to where the flame is at the inspirator. And yes Neil it backburns when not at the kiln.

There is one like this in the burner, not drilled as I have had since it was new. It is 0.75mm by my calipers, (and sliding a .5mm wire through). The gasfitter and I checked the orifices for critters etc and they are clear. I can't get the regulator to reduce the pressure to single digits though. Maybe I need another inline valve that I can use to reduce the pressure? Thanks for your help!

Thanks Babs - it back-burns even when right away from the kiln with flaps open.

Here is a bit more thank you Bill: The burner size is 50mm (2 inch) with capacity 400MJ (380,000 BTU) per hour @ 100kPa propane. The images show the burners being tried at 100kPa, controlled by winding the knob on the 500kPa regulator attached to the changeover valve on the 45kg 3.3Mpa capacity propane cylinder. Also shown is the burner installed, and burning back, plus the burner port as seen during building. I have put them all in one image, plus a larger one of the burning back. If I should include larger pictures please let me know. I also tested the burner in the open, off the kiln, on a small bbq propane tank with a regulator and also had back-burning. Thanks again for your help!

Thanks so much Bill! I will compile answers to all those excellent questions, and take some more pictures.

Hello folks, I have been trying for some time to fix a problem with a venturi burner that is burning gas back at the inspirator, and would appreciate any suggestions. The burners and regulator are capable of 250kpi and higher, but the two gas cocks are each1060 kpi. So far I have: Replaced one entire burner from the same company Had a licenced gas fitter check the nozzles and install the two burners. Tried with air fully open to closed. Tried at high pressure and low pressure. The burners and regulator are capable of 250kpi and higher, but the two gas cocks are 1060 kpi. It's got me stumped so any ideas welcome Thanks for pondering, Brett