steam lines to cylinders

This forum is dedicated to the Live Steam Hobbyist Community.

Moderators: cbrew, Harold_V

Post Reply
hoppercar
Posts: 616
Joined: Sun Jul 22, 2018 4:09 pm

steam lines to cylinders

Post by hoppercar »

bending up copper tubing, and fitting them in my smoke box for the steam feed lines to the cylinders. I used just the soft copper tubing in a coil, you can find at any hardware store. After finishing them, something tells me this might not be the best idea? Was wondering if the cinders and ash thru the tubes, will act as a shot blaster, and wear out the copper quickly? Thinking about bending up new feed lines, and using heavier gage stainless steel tubing?
User avatar
Fender
Posts: 3084
Joined: Wed May 02, 2007 8:33 pm
Location: Chattanooga TN

Re: steam lines to cylinders

Post by Fender »

I have had exactly that problem. But it took several years before the tubes began leaking. Someone suggested wrapping the part of the copper tubing that is directly in line with the fire tubes with soft copper wire, such as #14 wire, to protect it. Or, you could put a woven stainless sheath over the copper tubing.
Dan Watson
Chattanooga, TN
RET
Posts: 960
Joined: Wed Jun 07, 2006 8:36 am
Location: Toronto, Canada

Re: steam lines to cylinders

Post by RET »

Hi,

When I did the Boston & Albany smokebox, I spent quite a bit of time trying to get the best steam pipe alignment I could so I would be able to use 303 gun cleaning brushes on the flues and tubes. The Boston & Albany is 3 1/2" gauge. Now if you are able to access the tubes and flues easily, it follows that the ash and cinders should not be able to erode the steam pipes because the pipes wouldn't be directly in the line of fire. Thus, spending the time for proper alignment has two benefits as you can see. It took quite a bit of thought and finagling to get things the way you see them.
Inside Smokebox with secondary petticoat in place.jpg
Secondary Petticoat removed.jpg
The two pictures illustrate what I'm talking about. From them you can see how I've routed the piping as much as possible to avoid the tubes and flues. Each steam pipe comes off one end of the superheater header. This automatically puts the supply end of each tube to the side of the smokebox away from the cinder blast.

This engine steams much better with the secondary petticoat setup. With it, the exhaust pulls from both the lower smokebox and also the upper smokebox giving much better entrainment of the exhaust gasses and mixing of the steam blast with the gasses. I spent quite a bit of time playing with the setup and the results are well worth the time I spent. With the secondary petticoat in place, anyone can run it easily.

Richard Trounce.
User avatar
Fred_V
Posts: 4370
Joined: Sun Jan 12, 2003 3:26 pm

Re: steam lines to cylinders

Post by Fred_V »

I have cut strips of sheet metal and wired them onto the copper tubes. I can't imagine trying to bend SS tube to fit in there.
Fred V
Pensacola, Fl.
User avatar
DianneB
Posts: 733
Joined: Tue Aug 21, 2012 3:05 pm
Location: Manitoba, Canada

Re: steam lines to cylinders

Post by DianneB »

RET wrote: Sun Aug 12, 2018 7:03 pm .... I spent quite a bit of time trying to get the best steam pipe alignment I could so I would be able to use 303 gun cleaning brushes on the flues and tubes.
Having come from the full-size traction engine world where the tubes were brushed every day and before storage, I made sure that the tubes were accessible on my 1/2 size traction engine when I built it. Wise use of time - invest some up front to make it easier forever after!
User avatar
Bill Shields
Posts: 10459
Joined: Fri Dec 21, 2007 4:57 am
Location: 39.367, -75.765
Contact:

Re: steam lines to cylinders

Post by Bill Shields »

erosion damage is not limited to 'straight line from the flue', so anything that you can do to protect will be time well spent.

as suggested by others, just keeping the tubes clear is a very good start. In addition, anything you can do to protect the tubes will be $$ in the bank for the future.
Too many things going on to bother listing them.
RET
Posts: 960
Joined: Wed Jun 07, 2006 8:36 am
Location: Toronto, Canada

Re: steam lines to cylinders

Post by RET »

Hi,

Another factor in all of this is how much back pressure you have in the blast nozzle. If there is a lot, the engine will sound more like the real thing, but you will tend to suck more ash & cinders into the tubes at a fairly high velocity.

With the Boston & Albany, I have arranged things in the smokebox so there isn't a lot of back pressure in the blast nozzle (the engine doesn't "bark" the way some people like). Because of this, the tubes and flues stay pretty clean, there is less abrasion in the smokebox and there is a little more power at the wheels.

I'm not saying my way is right, I'm just pointing out some of the possible benefits of the trade off.

Richard Trounce.
Post Reply