Ok, first off, Jeff, I stand corrected, upon closer review of the pictures, you indeed have retained the copper/ red brass injector
steam pipes. Thank you for correcting me on this.
One thing about expansion and contraction, not referring to dis-similar metals, but to expansion of the locomotive front to rear.
Perhaps some of you have noticed when firing up a locomotive the bang or boom at the back end part way thru the fire up?
This generally due to the expansion attachment design at the firebox mud ring to the frame. It is good chance they or it is worn
and needs repair.
Take look at a number of locomotives, in particular, the bends in the steel or iron delivery piping from a lifting or non-lifting injector
to the boiler checks. That isn’t just for looks. Any straight runs from lifters to boiler checks usually meant the injector at bracket
was bolted but not super tight. Why? I have seen threaded side checks turn (slightly) at the boiler connection from expansion.
With leakage the end result. Brackets will move on boiler studs or be bent and piping will be difficult to make up the connections
due this. Your never going to eliminate all expansion or vibration. The idea is to be aware of and reduce it where possible.
I too have had use steel pipe on short runs turret valves to injectors or starting valves. Where possible I throughly annealed all
bends after trial fit up. I point this out as cracking at valve necks or at sleeve shoulders of copper pipe or with M iron unions can
happen. These areas should be closely inspected at least at 1472 day inspections to verify acceptable for service condition.
A few feet of copper pipe can be cheaper than replacing a turret valve or other major casting. Unfortunately, copper pipe of the
proper diameter and wall thickness is not always possible to obtain.
BTW the practice for annealing large copper steam lines was usually at a open top furnace. Torch use was not preferred.
Too easy to burn the pipe. Here again, a torch can be used but an Oxweld service rep explained to me years ago, don’t get
it (the heating tip) too close to the pipe and stay 12” to 16” away from the sweated sleeve. When annealing copper, water
quench helps remove any build up on inner pipe/tube surfaces.
A Pipefitter Forman at Burnham when asked what they used for sweating the sleeves (large or small) to copper pipe when Spelter
was no longer available said they were using silver-brazing rod. Good fit up, cleanliness and fluxing was necessary and start the
heating of the pipe 18” to 24” away from the sleeve/end of pipe area to allow for the proper capillary action to take place. It is
amazing how much heat the pipe will take to bring it up to brazing temperature. Very easy to burn the pipe or over heat the sleeve
burning out some of the metal composition. Stronger than silver solder and a little more forgiving of minor fit up problems.
BTW, for many larger pipe sizes on big power with higher boiler pressures, steel piping was used quite a lot. As I recollect, the NKP
ran the turret steam line to the Nathan 4000 non-lifting injector mounted on the end of the cast bed, thru a 3” Barco Ball Joint just
below the cab deck to take care of the expansion (over 1” ) boiler to frame at the back end.
UP had some good practices using steel sleeves.
Another practice was actually bringing the copper pipe thru the sleeve and folding it mechanically over the end of the sleeve and
jointing the surface.
Remember, locomotive vibration is from two sources: the locomotive during operation and the ‘water hammer’ when an injector is
shut off. Expansion is from temperature/pressure.
All this amounts to understanding the beast, preventative maintenance and to make the operation as safe as possible.
Also I am not blind to time and funds drive many repairs.
Questions or comments or disagreement welcome.
Chris
