Duplex vs Admiralty Brass
Duplex vs Admiralty Brass
(OP)
Hello all,
I'm lookin for some quick comparison numbers for 2205 to compare to SB 111. I want to know how much heat transfer I will give up if re-tube insitu. Thanks all.
I'm lookin for some quick comparison numbers for 2205 to compare to SB 111. I want to know how much heat transfer I will give up if re-tube insitu. Thanks all.





RE: Duplex vs Admiralty Brass
rmw
RE: Duplex vs Admiralty Brass
The real trick in the tube side flow, what happens when you reduce the pressure drop? Do you get much more flow?
If this is directly fed by centrifugal pumps then you will prob not see any change in overall heat transfer.
Can you keep the duplex from biofouling? SS isn't toxic like Cu is so things can grow on it if you don't treat the water.
We need to know fluids, flows, and system dynamics to give a better answer.
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Plymouth Tube
RE: Duplex vs Admiralty Brass
These exchangers are in clarified cooling water service with varying process fluids and ar gases. We should be able to keep bio-fouling to a minimum.
I've heard that many operators are standadizing on duplex vs. ad. brass. Thought someone would have a rule of thumb or have knowledge and experience.
We will do the engineering but I want to hear others' experiences.
Thanks all
RE: Duplex vs Admiralty Brass
If you go this route throw out old rules about wall thickness and do the pressure rating and vibration calculations yourself.
Remember that there is no corrosion allowance with SS, since all corrosion failures are localized.
And remember to raise flow velocities as high as you can. A good place to start is 10 ft/sec, there will be no flow erosion unless you have a lot of abrasive solids.
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Plymouth Tube
RE: Duplex vs Admiralty Brass
A star for you!
RE: Duplex vs Admiralty Brass
RE: Duplex vs Admiralty Brass
rmw
RE: Duplex vs Admiralty Brass
On another tack, if you change the bundle out altogether, with a tubesheet metallurgy to compliment or match the duplex, then you can change tube size, pitch, count; any of these, all of these in order to match your pump flow to your heat transfer surface. Give it a thought.
rmw
RE: Duplex vs Admiralty Brass
RE: Duplex vs Admiralty Brass
If there is any doubt then look at having an entire bundle with new tubesheets made. If you do this you could possibly change tube size or count to reengineer the heat exchanger.
2. You need to analyze the flow. Is the restriction of the tube bundle really what is controlling the flow? Where are your pumps running on their curve now? If the bundle is the major restriction and the pumps are above the BEP then you might be in great shape. Otherwise a new impeller designed for lower head/higher flow might be what you need.
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Plymouth Tube