LE Rotary Throttle Build

[rhbroehl]

Hi,

I am going to attempt to build a LE rotary throttle from their castings kit. Has anyone built one of these that could give me pointers and photos of the build or completed item?

Thanks

Rob

[jscarmozza]

Hi Rob,
I attached a photo of a spare throttle valve that I have in my parts collection, if this is the correct valve I'd be happy to take it apart and photograph the various components for you. I recently made a replacement smoke box throttle for one of my 1" Atlantics and it works pretty well, but there is a slight steam leak passed the seat. Everything in the valve is metal on metal and although the fits are all tight, I made the body from brass and the plug gate from stainless steel and the difference in thermal expansion between the two metals results in the leak. Keep things like that in mind as you build your valve.
John

[southwestern737]

I built one a couple of months ago for my Mikado, I didn’t use castings, just used stock. It works great and is able to handle much higher heat than any commercial valve the I have found. I followed the prints with one exception, I made the ports larger because I wanted the throttle lever to have a shorter throw.
Brent

[jscarmozza]

Good point by Brent on the port size, I used the same diameter port as the connecting tubing ID and the first half of the quarter valve swing is dead, the port doesn't uncover until the last half of the swing.

[jcbrock]

I'd be interested in anything you were willing to post, John. I've got a ball valve installed in a 1" LE Pacific but would prefer something like you've done, I think it'll last much longer.

[jscarmozza]

John, I sent you a PM.
John

[SZuiderveen]

Installing one of these in my new Ridge boiler for the former K Volrath Allen Mogul. Had to disassemble to turn it in. This version was built by John Esposito. Note inset tube sheet: there is not enough room between stack and end of boiler for front end throttle otherwise. Last photo is a recently acquired stock RSC throttle.

Steve

[Marty_Knox]

Steve, that is not a Little Engines throttle valve. That is based on a Railroad Supply throttle valve. There is an article about this throttle in the 'So you want to build a live steam locomotive' book.
The Little Engines Rotary Throttle Valve is larger.