On Petromax web site I noticed interesting listing of jet sizes and other information about different lanterns (around middle of the page): http://www.petromax.de/en/support.html I just copy them here for future reference: 500CP: Nozzle drill: 0,24 mm Diameter of needle wire: 0,23 mm Performance in watt: 400 Height: 40 cm Weight: 2,1 kg Tank capacity: ca. 1 L Burning time: 8 h 350CP Nozzle drill: 0,20 mm Diameter of needle wire: 0,19 mm Performance in watt: 280 Height: 40 cm Weight: 2,1 kg Tank capacity: ca. 1 L Burning time: 10 h 250CP Nozzle drill: 0,17 mm Diameter of needle wire: 0,16 mm Performance in watt: 200 Height: 32 cm Weight: 1,7 kg Tank capacity: ca. 0,5 L Burning time: 6,5 h 150CP Nozzle drill: 0,15 mm Diameter of needle wire: 0,14 mm Performance in watt: 120 Height: 29 cm Weight: 1 kg Tank capacity: ca. 0,33 L Burning time: 4 h Would someone list air cap distances for different lanterns since I don't remember them? It would be useful to have all impotant/usefull information in same place so we would not need to search them every time when information is needed...
Well, the power output is pure nonsense. It was a 1970s thumb estimate of the light output of a Petromax compared to an electric light bulb. The heat output of a 500 HK Petromax is roughly 1,2 - 1,3 KW. More technical details (from 1962 papers) can be seen over there: http://hytta.de/petromax/masse.htm Kind regards, Erik
Just to be a bit more accurate... The light output of which Petromax(CP?) was compared to which light bulb(W?)? _______________________________________ From that page in the link (hytta.de): 500CP: Air gap: 14,2 mm ±0,5 mm 350CP Air gap: 14,2 mm ±0,5 mm 250CP Air gap: 12,2 mm ±0,5 mm Pre heater(in all lamps): Nozzle drill: 0,20 mm Air gap for 150CP lantern is still needed...
It was more or less like this: A 500 HK Petromax lantern will give approximately the same light as a 400 Watt light bulb (of the 1970s) A 350 HK Petromax lantern will give approximately the same light as a 280 Watt light bulb (of the 1970s) A 250 HK Petromax lantern will give approximately the same light as a 200 Watt light bulb (of the 1970s) A 150 HK Geniol lantern will give approximately the same light as a 120 Watt light bulb (of the 1970s) Erik
There is some information on: www.petromax.nl For the output: Personally I guess that there was a change in output when the manufactures changed the dimensions from HK (Hefnerkerze) to CP (Candlepower). So the 100HK lantern became 150cp. If you do the maths on the jet bore then you will see the values theoretical possible. Tip: http://petromax.nl/PX_tabel.html scroll down to the german explanation of Ludwig Gebauer.
My smaller Petromax with 1 L tank (must be rare) looks like it has a gap of 6mm from top of the nozzle to air intake.
Hello and welcome @Swerige ; can you post an image of your lantern ? A Petromax with 1L tank is not small or do you mean one of these ex-Swiss army models with a 250 lantern on a 1L tank ? Petromax 523/821 Either way, the gap needs adjusting or the lantern will not burn correctly.
Hi and thanks for your quick reply. I guess that you guessed right, this must be an Petromax 523/821. I don't know a lot, I got this (not the new 500 as i include for size comparison only) from ebay. What I know: The glass dimension looks like a 250 lantern. Dubble tied mantle. Old burner. Cut out in the hood that prevents it to be fitted in wrong direction Says Petromax on tank, pump, manometer, handwheel, inner casing and hood. The airgap looks vey small, can this be right or any suggestion to fix that? (Or maybe this would work better if i convert this to 150 by changing the nozzle)
It's meant to be a 250 lantern so I wouldn't change the jet (nozzle), I'd adjust the gap. This guide will help you to understand how your lantern works and how to do maintenance, it is for a 500 cp lantern but the procedure is the same for 500, 350, 250 and 150 lanterns. I recommend you read all of it. https://classicpressurelamps.com/attachments/px-rest-pdf.57117/ Page 8 shows the parts and page 9 shows how to adjust the gap. Of course, because your lantern is 250 cp, the gap needs to be adjusted to 12.2mm not 14.2mm. You can use a 12mm drill to set the gap if you don't have a Petromax wrench. The straight vapouriser (förgasare) is designed for gasoline but if anything goes wrong, the only way to extinguish the lantern is by releasing the pressure which of course means gasoline fumes which could ignite and you'll have a fireball. Personally, I prefer to use kerosene, it works here in the U.K. but it doesn't like strong winds and I don't know if it will work well in the cold winters you have in Sweden but there's nothing to stop you adding 10 or 15% gasoline to the kero to make it a little more volatile. Read the guide before starting work, have fun and stay safe.
