Hey. I have read on this page that several people have problems removing the return valve in old lanterns. I have that too. These are a Maxime and a Hasag, where both return valves are stuck. the valves are with straight notches. Is there a method to remove these valves without damaging the notch or using a drill. I have tried with penetrating oil without success. All help is gratefully received. Tom
Did you thought about left thread ? I have found left threaded valves in some lanterns. Ultimate solution is to solder out the pumptube. Remove the valve and put it all together again.
@WimVe Thanks for your reply. So far I have not thought. Have never had a pressure lamp where RNV was with links thread. I try, and if I do not succeed, I have to find a professional who can solder silver. Can silver soldering be performed on steel? The container is made of steel, and the pump tube of brass on my Hasag. Maxim is all brass. Tom
As for soldering: I don't know if they soldered with silver in those days. But indeed steel/copper needs a good approach. As for the thread direction: always with care !
The green threads are right hand thread, the red ones are left hand thread. Not all Hasag and Ditmar NRV's have this left hand thread.
I had to do this on a Hasag with steel tank. The pump tube was fixed with ordinary (?) solder, definitely not silver solder. After I repaired the NRV, I used 60%tin / 40%lead solder to fix the pump tube back into the tank.
@Henry Plews Hi Henry. Thanks for the answer I have seen this tool here in the forum but where can it be purchased. Sincerely Tom
@Tom Pedersen 50/50 of transmission oil and accetone is a good penetration oil. You could try heating cooking oil pour into tank to heat the bottom of you pump may work for you
Before trying more radical approaches it could be useful to try and heat the fount in the oven at a low temperature (say 100 degrees Celsius to avoid melting any lead solder that may have been used on some part) and then use a tool like the one pictured above.
@Tom Pedersen I don't know, I got mine at one of the Petromax meets but I can't remember who I bought it from or where or when. Are you able to make your own ?
@Tom Pedersen, The pump valve key or wrench was part of the swiss armee HASAG boxes. They tend to pop up at ebay or meetings if someone has more then one found. These sources however dried up. The key is handy because it fits perfectly, so any tool or addition (to a screwdriver), which makes a perfect fit, will do the trick.
