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Condensation Pipe for Thermal Test System


I'm designing a test chamber that will fill with very cold -3 degrees C 5% saline water, then drain the water and heat the chamber up to 150 degrees C. There will be very little steam each cycle cold-hot, but a test may run for 200+ cycles and I want to prevent the imbalance of the salt solution.

I want to run a vent from the chamber that connects to a pipe where the steam will condense along the sides and drain into a reservoir tank underneath the chamber. The system is powered by gravity.

I'm looking for a material that would be good piping for the condensate. I've read about PVC, but I'm nervous it will be affected by the high temperatures. Another person mentioned copper, but I also read that that is not a good idea also.

Could I use PVC or another kind of plastic piping? Or do I need to go with steel/carbon steel.

Any information would be greatly appreciated. Thanks.


  • Jamie Hall
    Jamie Hall Member Posts: 22,912
    Really need more information to specify what would be best. The two most important questions to start are first, how pure do you need to keep that saline solution? and, related, what do you do with the condensate once it gets into the reservoir tank?

    The reason these two questions are critical is that from an overall standpoint, disregarding the purity consideration -- or in the event the condensate goes to waste -- the best material overall will be threaded black iron pipe. If the fittings are arranged with some thought, the threaded connections will take care of any expansion issues without any problem. However... black iron does rust. Only slightly, but it does, and if that saline solution must be kept pure you may not want the iron contamination.

    I wouldn't use copper. It also corrodes, for one thing, and the usual methods of joining don't allow movement for expansion.

    Nor would I use PVC; although some types of PVC are rated for steam temperature... I distrust it for that.

    Nor would I use steel or carbon steel -- that really rusts fast.

    However, you might be able to use stainless steel with corresponding fittings and suitable provision for expansion. There are also other non-corroding alloys -- monel, for one -- which could be used.

    But if a bit of iron in the condensate isn't a problem -- black iron.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England