I'm trying to round up some air brake components to upgrade several units to a 26NL air system. One item we need is distributing valves. I had always thought that a 6NR was necessary for a 26NL conversion, but we were offered sone 6N valves that we were told would work.

Just what is the difference between a 6N and a 6NR? My understanding, and it may be faulty, was that the 'R' in 6NR stood for rubber, that the valve had rubber diaphragms and O-rings instead of all the brass parts that the 6K (old 14 and 6 systems) used.

Any guidance here would be appreciated. Also, I have never seen a 26NL air brake manual. Is there such an animal around?

EDM

EDM,

I have a 26NL manual in .pdf form. Send me your email address and I will forward.

If memory serves me, your take on 6N vs 6NR is correct.

DPK

The big differance is the plate on the side with 4 bolts. No pipe fittings/ No M/U ability. pipe fittings and you can M/U it. (you must have all of the rest of the components to do so). All you have to do is change plates. DO NOT LOOSE THE "GOLDEN" PLATE. If you find one someone who will part with one you will pay for it.
If you not going to M.U. it you can save some money by using a 6K. I've been told the 6K is actually a better built valve due to the lack of rubber seals in the wear parts internally. Never took one aprt to find out if that is true though.

DPK sent me a PDF of NYAB circular 105, dated February, 1966. It calls out a 6NR distributing valve, but uses the ports 2 and 4 on the type "R" combination pipe bracket/reservoir. The 1980 Loco and Car Cyc has a few pages of 26-FNL, which utilizes a 6NR variant with the "golden plate" that Jack mentioned, which also has ports 2A and 2B, with a double check between them.

It's plain to see that there are several ways of doing this system. I'm looking for something low maintenance that will MU with 24 or 26 systems, no need for 6. Is the sytem with the plate and ports 2A and 2B the way to go?

The shortline that we have equipment on has converted several GP-9s from 6 to 26NL with the plate with the two ports, in fact the MM there makes up his own. (Which may answer my question above-) I have even sketched out the plate for myself. But are the 6N and 6NR the same internally, with the plate being the difference between N and NR?

It seems that the more information I get, the more confusing the nomenclature becomes-

It is mentioned by another brake expert that the 24RL could not be mu-ed with 6ET or 14EL brakes (or vice versa) unless the 6 & 14 systems were "modified".

I think the #6 and #14 systems need another pipe in their piping to accommodate the third-pipe on the #26 system.

Could the needed modification (to the #6 & #14) be the "golden partition" that was talked about above, that mounts between the valve and the reservoir on the 6K/6KR and/or 6N/6NR?

I have read that the "R" in 6KR (this is earlier than the 6N valves) means that its a 6K valve and that the reservoir is one of the new type "R" reservoirs, that has the bolt-on o-ringed spigots (instead of the older female pipe threaded holes) in the reservoir.

I also see that on the , the 6FNR Distributing valve (the last model distributing valve ever) there were no "Golden plates" shown, so WABCO must have worked around that modification by adding the clearly visible; tapped holes in the cover plates and the valve. The tapped holes everywhere were presumably to plumb it into a 26C system that requires more pipes. The "Golden plate" in the older distributing valves could have been there to solve the same problem that these extra connections in the 6FNR cover plates were there to perform, to; supply the extra plumbing connections to operate in MU with the 26C brakes.

What do you guys think, Different path to 26C and MU compatibility, but with two paths; the Golden plate in the older versions, vs the ported cover plates and extra plumbing in the last version?