Mike and Jim,
Thank you for Your answers!
I am used to steamlocomotive boiler repairs and retubing since almost 10 years now. It is always interesting to see how ohters handle the issues.
Jim, you indicate that tube ends are rolled in and not welded - otherwise they could not get "loose" and need rerolling. With a leaking tube I meant a tube that has a "hole" in it. As you said, leaking tube ends can be rerolled, but generally not more than one to two times until they get too thin. Another problem is the scale that builds up between the tubesheet and the tube as long as there is water (or steam) blowing through - doesn't help at all.
I would not reuse boiler tubes in a smaller boiler, only if they are very very good in condition.Yes you can fit another boiler with "new" tubes very cheap, but then you must keeo in mind that they won't last as long as new ones would. What if the do not last until the next boiler examination - you did not safe anything...
How many broken stays are allowed in a boiler? Here in Switzerland we have very restrictive rules regarding broken staybolts - the most restrictive of any other boiler rules I could think of...
Changing entire fields of Staybolts makes sense if you unpacked / removed the boiler anyway and the staybolts are showing signs of thinning.
At the moment we are changing all the staybolts on one of our boilers, we had to lift the boiler off of the frames for a repair and decided to do all the staybolts to make sure they are all OK for the next few years and we hopefully don't need to remove the boiler again anytime soon yust to replace a single staybolt where you could not reach to..
Very best Regards,
Urias
