Bending Exhaust Steam Pipes

ikcdab · Post by **ikcdab** » Mon Feb 09, 2015 7:43 pm

I am just starting putting together a Roundhouse Lady Anne Kit.
The cylinders come with long copper exhaust pipes and the instructions say to "bend up and out of the way - be careful not to snap the coipper from the cylinder"
I am wary on two counts:
1. whenever ive bent copper pipe before, it has kinked. How would i bend these without kinking?
2. the pipes are rather loose in the cylinders. i am afraid to screw them in tight for fear of stripping the threads on the copper pipe.

Any advice? Thanks!

PS: ill start a new separate thread soon to catalogue the whole build.

DLRdan · Post by **DLRdan** » Mon Feb 09, 2015 8:26 pm

I wouldn't worry about the pipes being loose, they are only the exhaust. The best thing to do is anneal the pipes where you want to bend them then bend it a bit at a time, re-annealing as soon as it starts to harden up.

ikcdab · Post by **ikcdab** » Mon Feb 09, 2015 9:04 pm

Thanks for the reply. So annealing copper pipes - do i just heat them up on the gas stove when the Mrs is out?

DLRdan · Post by **DLRdan** » Mon Feb 09, 2015 9:58 pm

Pretty much, you want them to be at least a dull red colour then leave to cool naturally.

Big Jim · Post by **Big Jim** » Mon Feb 09, 2015 10:14 pm

Try a brake pipe bending tool as used by mechanics.

Chris Cairns · Post by **Chris Cairns** » Sun Feb 15, 2015 5:00 pm

Just did mine on a Roundhouse Billy kit yesterday.

As I'm planning to upgrade this to a Riverdale Elke in the future I had to allow sufficient length before the upward bend (Elke uses a T piece on the exhaust pipes for the blast pipe). Took the cylinders off to remove the exhaust pipes, and after measuring the required horizontal length, annealed the pipes. Put an old Mamod drive band down the inside of the pipe (reduces or prevents kinking) then formed the upward bend around a suitable screwdriver shaft. These pipes (at least on the Billy) need to go in front of the superheater T piece so require a further curved bend on the vertical portion to fit around that T piece. Due to the extra length required for the Elke conversion I've ended up with the exhaust pipes on the opposite side of the chimney (i.e. left cylinder exhaust pipe is on right side of chimney).

Chris Cairns

Keith S · Post by **Keith S** » Sun Feb 15, 2015 5:39 pm

The pipes on those Roundhouse kits should come pre-annealed. At least the ones in my kit were very soft and bent to shape easily with light finger-pressure. You only need to bend them once, so they point up, and they don't need to be tightly screwed into the cylinders. Even if they are a bit "floppy" they are held in position once the smokebox is added. Also if you wish to put a "chuff pipe" on them later, it's nice to be able to move them a little.

The lubricator and regulator piping in the cab is the same. It should be pretty soft and easy to bend. Just don't try to make it go around any tight corners and I don't think you will need to resort to any tool-use or advanced techniques in this case. Roundhouse already anneals the copper for this purpose. It will harden up the first time you steam it.

Frankly, I think even if you did slightly squash a pipe, you wouldn't notice. I don't think I've ever opened the regulator on mine past a quarter-turn, there's so much steam to spare on a Roundhouse engine, if one of the pipes was "throttled" a little you would barely notice it. I could be wrong about that.

The piping was not difficult on my kit. You'll see it's nice and soft. You won't need to re-anneal it. as long as you don't worry it excessively trying to get it perfect.

Chris Cairns · Post by **Chris Cairns** » Mon Feb 16, 2015 2:32 pm

Hi Keith,

My Billy kit is over 10 years old so I thought it best to anneal all the pipework again.

I just have to trim down the fibre washer on the regulator housing to get it to sit at the right angle then bend the last pipe between the regulator housing & the lubricator (the syphon tube will also need re-bending so it does not foul this regulator pipe).

Chris Cairns

ikcdab · Post by **ikcdab** » Mon Feb 16, 2015 9:50 pm

Many thanks for all the replies, very useful. Thanks again.

Keith S · Post by **Keith S** » Mon Feb 16, 2015 11:25 pm

I am wishing that I'd spent a little more time thinking about the cab layout on my kit "Billy". I think I might have (in retrospect) tried to get a lubricator that drains from beneath, or maybe soldered a little extension onto the drain with a little valve on the end and mounted it in the front of the cab on the left-hand side of the boiler, with the steam pipes closer to the side of the boiler. This would make it possible to put a little man in the doorway and also I could get one of those DJB realistic reversing levers. I might have tried to bend the syphon so the gauge could be further forward too.

Maybe I will get the energy to do these things later. Right now the only thing I think would be better about the "Billy" is to have a less cluttered cab.

Chris Cairns · Post by **Chris Cairns** » Tue Feb 17, 2015 6:35 pm

Not sure if Rob Bennett still does his clip on Roundhouse lubricator driver figures. As he is attending Peterborough as a trader I'll send an e-mail enquiry shortly to confirm if they are still available.

Chris Cairns.

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Bending Exhaust Steam Pipes

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