Tuesday, October 4, 2011

Inside the Triple Valve - Part II

There has been little progress removing the larger end of the quick action portion on the 308's valve. I'll need a bigger wrench. (Maybe I can borrow one from the Car Shop when nobody's looking. Shhh -- don't tell anyone!) Meanwhile, let's finish disassembling the slide valve portion.

Here are all the parts neatly numbered. 1) The piston and its stem. 2) The graduating valve, just a flat piece of metal. 3) The slide valve, which wraps around the stem. 4) A small leaf spring to push the graduating valve onto the upper part of the slide valve. 5) The spring which pushes the stem down onto the slide valve seat.

Here's a better view of the graduating valve and the upper surface of the slide valve. All these parts need to be cleaned of any grease or dirt, then slightly lubricated with graphite.

The slide valve itself is 1 1/16" wide, and the graduating valve is 7/8".

And here is the graduating valve inserted into the stem. The parts are cleverly designed so that you can't assemble them the wrong way.





Finally, here's a sample color plate from a Westinghouse manual on triple valves, which is about the size of a Bible. The upper picture is the Release and Recharge position, and the lower is Service. The various colors indicate the air pressure in each passage: yellow is brake pipe, orange is atmosphere, etc. This is actually an L triple for steam-road passenger cars, since I don't have a similar book for electric car equipments. The L triple is very similar to the M; the main difference appears to be that the L has a built-in safety valve, which evidently wasn't thought necessary for electric service. And then there's page after page explaining in detail what happens in each position. This is really high tech for the cast-iron era.

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