As a carbide caver in my younger days. And having had a number of the lamps both old ones and the more just modern Justrite brand . Don't know if your internet info, mentions the two most important things after having a gastite seal between the carbide chamber/gas compartment. A lot of people would lose the rubber gasket and the gas would leak out and catch on fire when it was on the hard hat/helmet. Since it wasn't under much or any pressure it was a lazy type flame. Interesting to see none the less and the persons reaction, 3 hours in a cave!
Have a positive water drip shut off, so it will stop generating gas.
DO NOT use any form of clamping device if you use a hose from the lamp unit to the generating unit if they are separate as a belt generator unit. That way if you generate more gas that you use it can blow the hose off before the pressure gets to an unstable number.
As it is 15psig in the atmosphere, that is the unstable point.
Here in the US they were also favored for nighttime hunting of raccoons. Union carbide was the largest manufacture and seller of the carbide. In rural areas you could find it at almost any hardware store in years past.
Also on an environmental note, the spent carbide after it has generated acetylene gas,turns into a sticky powder while wet. It is considered a toxic/hazardous material. Be careful were and how you dispose of it.
It will kill wild life and pets, and water life if it gets into a stream or pond.
Plus clean it out of your generator section when you recharge the unit. It is a royal pain to remove after it dries and can after time be corrosive to the canisters.
As you have probably found out, googling carbide lamps will bring up a skip load of hits. I have to see if I have any photos of the lamps and the inside working end of them.