Hi there, after my trusty optimus nearly started a forest fire due to a non return valve (NRV) not closing properly, and me having to cook on a camping gaz stove for the rest of the holidays (shame) I yesterday repaired the delinquent. The trickiest thing was to get that thingy loose on the bottom of the pump tube - made a tool for that on the lathe. With the NRV out, and one helpful pic from the German petromax forum (stove section) I was able to figure out how to disassemble that valve. The valve has only a piece of rubber as working item, and that was a bit compressed, so it became wider and jammed in its tube. I sanded it down a bit, to get the necessary play. Therefore i fixed it in the three jaw drill chuck, let it run on highest possible speed and grind it down with some sanding paper. After reassembly I replaced the hard rubber seals on Pump and filler cap with sparkling new O-rings from a set I hat lying around, and checked the pressure valve (after dis/reassembling and cleaning it) with compressed air. Well, but the stove did not work yet, because that modern pump failed. I then threw away the O-Ring and grabbed a spare pump leather (presumably from my phoebus 625 spares) which fit nicely. After cutting a M5 thread i could fix it between two washers on the pump rod. Test run in the back yard produced gorgious coffee in my Bialetti espresso maker. Further testing at the motorcycle races this weekend proved not only sucessful repair, but also better performave due to the pump leather conversion. I'm happy again! For future travels (the optimus lives in my 4WD camper van) i ordered a Petromax NRV which has three major advantages: 1) you can open it abroad with a simple screw driver 2) the rubber is in a brass housing, so it won't jam as the old one did 3) the rubber is replacable by something I am able to make from any piece of petrol resistant rubber ... cheers Andy
that's some info all of us wld like to know. Especialy those of us that have 111Bs w/ blown out NRVs. Not what one has in mind as a camp fire! My codolances about the camping Gaz, P.O.S., I got stuck w/ one of those, took all morning to get coffee made. Aaron
Hi, I ordered that petromax NRV at the Petromax lamp store here: http://www.pelam.de/ I do not have it yet, ordered it as a spare. If the shop fools you (it did not work with me), you can also order via email. pump leather: http://www.pelam.de/product_info.php?manufacturers_id=&products_id=104 NRV: http://www.pelam.de/product_info.php?manufacturers_id=&products_id=106 Andy
I picked up a new 111 pump rod and 20 NRV valves off ebay recently. The NRV's won't fit a 111, but the spring and bung do 8) Also fitted a 111 NRV in an Army 2 pint Monitor stoves, works fine too.
yeah, what mine needs is the inner cylinder of the NRV. the area that the spring and bung reside. Mine cracked and split at the end. No fuel coming in yet, but after about 2 to 5 mins of running, the pump starts slowly coming out. Kinda alarming, I'm doing this indoors so if it goes "POOF!" I'm in deep...yeah.
Hello Motorang, Please tell, is that a rubber/nitrile seal on the NRV ? I have never seen a seal like that before.
Hi, I also only know that picture. When I disassembled my 111b (I bought it new, so thats original), there was either no rubber seal, or it stayed on the ground of the pump tube when I unscrewed the NRV. Andy
On second thoughts, might they be the lead seals? I suspect that the lead seals on my stove's NRV are stuck down at the bottom of the pump cylinder too.
Optimus NRV's come with the Lead seal, but a nitrile/vuton/teflon washer would probably work as well.
The last ones I got from BaseCamp a year or two back had a "plastic" washer, not a bit of lead in sight.
Hi! The usual old NRV fitted to any Swedish kerosene stove, pressure lamp or blowtorch (may it be Primus, Optimus, Radius, Prince, Svea, Svecia or whatever) had a lead seal. The ones sold today have a plastic seal and slotted head. On the left is a NOS of the old model and on the right is the new one. Isn?t it wonderful? That small gadget used for more than a hundred years and still considered as just as functional. I think you can recognise human ingenuity in the small, ?simple? inventions just as well as in big complicated stuff. Stefan
As with many manufacturers, I'll wager most if not all the stove makers bought small parts from independent suppliers as long as the parts met the necessary specifications. So any given model of stove could have one of many parts made by any of dozens of contractors in any of dozens of countries. I have stopped assuming that differing parts and bits denote a different model. I am amazed at the near universal interchangeability of what I call "expendable" parts for pressure stoves. My Canadian made Coleman pressure stove has an NRV marked "SWEDEN" as does my German Aida. There's no way of knowing if they are original to the stoves, but they fit and function. Those are the really important attributes. Gerry
