I would think that generally no valve would have lead seals. Simply because they don't seal without a lot of mechanical pressure. And even then they deform.
@ColinG It's been a long time since I've used lead for NRV washers. Instead, I make them from Nitrile rubber and they hold up great. In addition, the RNV is considerably easier to unscrew. Tom
@ColinG All the ones I have found or replaced on Vapalux/Bialaddin/W&B lanterns have been rubber/viton and I have never found a lead one. 300x onwards.
Speaking of such, the "Handi" lantern has an NRV with a slightly smaller thread, at 7.5 m/m O.D., than that normally encountered at 7.8 or 7.9 m/m approx., so I'd very much like to obtain some washers 7.5 x 11 m/m in lead and/or in Viton. The smaller size is a much closer fit. Plus another chap here has four Handi's, and he too is having his a battle to extract the valves for servicing. Any ideas, pointers, for some close-fit washers ?Thanks.
As it is out of view you could trim anything with the right size hole ? Not pretty but it would work.
I use a viton O-Ring on most of my NRVs which work very well and it makes it much easier to remove. Cheers, Norman
I have plenty of lead I could use, but the often resisting-to-extracting of the NRV due to a spread out lead washer made me look for an alternative. I chanced upon a suggestion by BernieDawg - of silent cap fame for stoves - to punch rings out of the plastic lids from yogurt containers and the like. Only to be used once, but cheaper than chips. However, one has to invest in a concentric punch set that might even be more expensive for Britons now (Boehm, France). They work, are even acetone resistant , and child's play to remove.
The fettlebox has NRV refurbish kits with a lead washer, I’ve used them on a number of different lanterns, no issues
Colin, as far as I am aware vapalux/bialaddin have never used lead as a washer in any of their lamps. Regards Ian
Pressure stoves (Primus, Optimus etc) have lead washers for sealing their NRVs in the bottom of the pump tube. My preference is to use lead for Primus-type NRVs but a good alternative is HDPE plastic used in milk bottles etc. The last fettle I did on a Bialaddin the lamp had a rubber washer on the NRV so I replaced it with a viton one from The Fettlebox. @Paul Aslanides I would use lead for the NRV in the Handi. They are quite easy to make if you’ve got a bit of lead flashing. For hard to remove NRVs, half fill the pump tube with Penetrene or similar and leave it for a few days. Put your NRV extractor in a vise so it can’t move, put the tank/pump tube over the extractor in the correct position, and then hold the tank firmly against the extractor and turn unscrew. Tony
@all, I was put on the wrong leg with the word seal. I thought the part that seals inside the valve not the o-ring that seals on the outside of the valve.
OK, I think I've got a good idea of what was used and what it can be replaced with. My only problem is that all of the lanterns I've received have had lead washers! It doesn't matter though as plastic milk container tops are plentiful and easy to cut. Thanks guys.
On the other hand, I don't think I've ever had a Bialaddin / Vapalux which came with a lead washer anywhere. Neither have I ever seen an official seals kit from Halifax with lead washers in them - and I've seen a lot over the past 20 years. They're always rubber of some sort, except the rare red plastic (Catalin?) NRV washers on very early E41s...
In the reference library there's an E41 instruction card ; the parts list on the back mentions a lead washer, presumably for the NRV...
So far I have not found a lead washer underneath a W&B non-return valve, including two E41's. Instead, some non-definable fibre or plastic that was deformed by the NRV. Yet I am not surprised a lead one is mentioned in a parts list of an E41, when the best of intentions were proclaimed, but an economic realisation might have made it a thing of the past soon. Perhaps spurred by war requirements?
When Fettle becomes Battle - Always had great difficulty getting the NRV in the Handi lantern to seal. Finally put a rotary wire brush down into the pump tube, a risky business, and Lo ! loosened and removed the remains of old washers, been in there for years. One lead and one of the quality gasket material, Klingite or somesuch, which did work for a while but has since disintegrated. Peering down into the pump tube with a torch, it's difficult to make out exactly what is down there. Then had to pluck out the bits of detritus with a rod and rag with grease on the end. The quaint little Handi NRV, smaller than all my other NRV's, has a chamfered face so that instead of pressing the washer against the face of the pump base, it actually spreads the washer - splays it outwards, i.e. from the inside diamter, radially outwards. A proper pain, because a new lead washer is instantly deformed when the NRV is tightened down. With a thread of 7.5 m/m od there are no suitable lead washers, or punches about. Arrgghh! Couldn't find my lead sheet, so made a washer from annealed copper. Yes, so far it's O.K. Better than lead, I expect. Also put in a new NRV kit. The old pip was without the little brass cup, quite good, easier to handle. The young fella who serviced this Handi many years ago, twice, has since moved on to other pastures, probably the meatworks, where his talents as a butcher would be more appreciated.
Well done on the fettle, Paul and thanks for sharing! Sometimes it's little tips like this that can really help
Thanks. I thought the wire brush trick rather barbaric, but it was a last resort, since nothing would seal there had to be something wrong. I shall cut some more annealed copper washers, for standby's. Not as soft as lead.
Lead washers are fine. So are HDPE ones. HDPE is available almost everywhere as the material of choice for making lubricant and chemical containers. They are resistant to all organic solvents I know of, most acids and alkalis. You can easily punch the washers out of these. Not as heat resistant as lead but these are pretty resilient and can be reused over and again. Another excellent material is hard PTFE sheet(not the Teflon tape) but is relatively expensive. They are resistant to almost any known chemical, soft enough to deform to the required shape and can be re-used many times over. Unlike rubbers and elastomers, they are quite tear-resistant.
@Paul Aslanides Australian plastic milk bottles are made from HDPE. They make good washers. For a thicker HDPE washer, use an ice cream container. Cheers Tony
Simple; lead washer out , lead washer in. Problem is, sometimes trying to figure out if the lead washer is still affixed to the bottom of the pump tube. If it is, and you don't realise it, then it reduces the amount of thread left for engaging. The NRV extraction method outlined by @Tony Press works well for difficult ones. I find an initial test of the extraction tool to see how much play exists, useful. Too much play, i.e., a bad fit and you damage the head of the NRV. I tolerate about 15 degrees and no more. I have a series of removal tools, many just home made, to get the 'perfect or at least close' fit. I've only ever stuffed it (removing the NRV) up once by too much force (ripping the pump assembly from the fount) and knowing what is a reasonable maximum force to apply is worth knowing too. Ah the joys.
