Two tone whistle valve, can you ID?

David H. Hamley · **Joined:** Tue Aug 24, 2004 3:07 pm **Posts:** 705

Pennsylvania Trolley Museum has applied a two tone (loud, soft) whistle valve to our 25 ton GE. It works fine, doesn't leak when closed, but pull the lever and it seems like there's more air coming out around the stem of the plunger than going to the whistle. Obviously something is either worn out or missing. But we need to know what should be there. There have been various suggestions of maker of this device, Nathan, Viloco, Prime, or Graham-White/Salem. I've got a couple images available, but they're too big to attach here. If you think you can help, please PM me and I'll forward separately. Thanks!

robertmacdowell · **Posted:** Wed Feb 20, 2013 7:58 pm

Dave sent me the images and I stuck them in the Shrink-o-Matic and set the dial for RyPN.

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duplex_valve_2.jpg [ 41.22 KiB | Viewed 3960 times ]

Alexander D. Mitchell IV · **Posted:** Wed Feb 20, 2013 8:19 pm

A rather old Nathan Double Stem Air Valve. See Page 8 here:

http://atsfrr.net/resources/BrownPaul/Horns/Nathan.pdf

Here's a link to a diagram:

http://www.hornwhistleboard.com/downloa ... =16151&f=2

which came from

http://www.hornwhistleboard.com/viewtopic.php?p=48150

See this quote from Page 2 of that discussion:

Quote:

I have one of those, and would have liked to use it but couldn't get it apart to restore the seals. The brass valve "cartridges" are completely corroded into the aluminum body and are impossible to remove. The torque required to remove them would exceed the strength of the brass - so I left it alone and have it as a "wall hanger."

David H. Hamley · **Joined:** Tue Aug 24, 2004 3:07 pm **Posts:** 705

Thanks, Sandy, for the info. Confirms my suspicion that there are O-rings in this thing that have become petrified with age. We'll try a gentle application of BTUs to the aluminum body to loosen the brass seats. There is no sign or corrosion on this valve. Likely the local NAPA will have in their O-ring assortment something that will seal it up reasonably well. This valve came out of an Alco S4 that in turn came from the Ford River Rouge plant. Might have been original equipment as these locos were built in the early to mid 1950s.

David H. Hamley · **Joined:** Tue Aug 24, 2004 3:07 pm **Posts:** 705

This is to update Pennsylvania Trolley Museum's experience with that Nathan dual tone whistle/horn valve. We got it apart without damage, PB Blaster did the job of loosening things up, then a 9/16" 8 point socket easily unscrewed the two valve bodies. Aside from some petrified O-rings, easily replaced, the "Disk Assembly" appears to have at one time been a composite of a rubber material overlaid on a brass valve disk. The rubber was present only in small remnants, petrified like the O-rings. By chance does anyone have one of these disk assemblies that still has the rubber in place? We'd like to have a better idea what it looked like in order to recreate it.

The valve is on our 1953 vintage GE 25 tonner, recently converted to 62.5" gauge and run for the first time in many years on April 6. So far our worst problem with the number 89 loco is that leaky whistle valve. From that standpoint, we ain't doing bad at all.......