open to atmospere caustic / HCl vessels
open to atmospere caustic / HCl vessels
(OP)
Hello once again,
I have another question for solving. My designers are designing vessels for 14.9 psi to keep from using an ASME code stamp. The problem is this:
These vessels will be located in the hot tropics in direct sunlight. There is to be a 2" open vent on each vessel as over pressure protection.
Question: Will condensation form on the inside of the vessel wall due to normal heating and cooling from the sun therefore diluting the HCl and Caustic which would increase the corrosion rate?
Evaporation and dewpoint calculations are totally unfamiliar to me.
Please advise....
I have another question for solving. My designers are designing vessels for 14.9 psi to keep from using an ASME code stamp. The problem is this:
These vessels will be located in the hot tropics in direct sunlight. There is to be a 2" open vent on each vessel as over pressure protection.
Question: Will condensation form on the inside of the vessel wall due to normal heating and cooling from the sun therefore diluting the HCl and Caustic which would increase the corrosion rate?
Evaporation and dewpoint calculations are totally unfamiliar to me.
Please advise....
Richard Schram
Mechanical Integrity Specialist
Pharmacia Global Supply Arecibo-P. Rico
rschram@pharmacia.com





RE: open to atmospere caustic / HCl vessels
Answer: probably...... Most tanks in the tropics are painted a light color to mitigate this effect.
As an apiguy, I am sure that you are aware of the design standard API-2000 that sizes vents based on several criteria...... This guideline can be used to evaluate the 2" vent line size.
Some companies make dessicant driers for tank vents
Try www.drytechinc.com as a start.....
MJC
RE: open to atmospere caustic / HCl vessels
RE: open to atmospere caustic / HCl vessels
Unfortunately, our vessels are painted pretty much like they are everywhere else....Dark Blue Caustic, Dark Red HCL.
twjag-
Your information is exactly the concern I have, although I cannot convince the designers that a corrosion problem may exist.
Thanks for all the information guys, I am forwarding it on....
Richard Schram
Mechanical Integrity Specialist
Pharmacia Global Supply Arecibo-P. Rico
rschram@pharmacia.com
RE: open to atmospere caustic / HCl vessels
Why don't you build the tanks out of fiberglass/vinyl ester and be done with it? You can have tanks built to standards - Section X or RTP-1 - and not "stamp." This type of construction, if properly fabricated, can be resistant to almost any concentration of NaOH or HCl to 150F. If higher temps are needed or there are dissolved organics, fiberglass can be mechanically bonded to a thermoplastic (polyolefin or flouropolymer) liner to give even better corrosion resistance.
Let me know if you want more information about this. I know someone who builds these type of tanks.
Greg Hopkins