RE: Piping Systems for High Purity Deionized Water

Bruce:

thank you very much for the recommendation. very cogent and complete.

i'll consult with the process guys for their input.

one question, why nitric acid rather than hydrochloric?

At 09:01 AM 5/21/2002 -0500, you wrote:
>Thomas:
>
>I can give a generalized recommendation, but specifics need to be
>tailored to the specific use. There area also considerations regarding
>capabilities for rinsing, much the same as one would do for pickling or
>passivating in place. Start with an organic solvent rinse (10% methyl
>or ethyl alcohol is fine, but generally avoid oxygenated organics),
>preferably circulating for several "volume changes", then a "tap" water
>rinse, then assuming that the circuit boards are acid etched, follow up
>with dilute nitric acid solution (not more than 1 Molar, not less than
>0.1Molar is needed), then a thorough rinse with the pure water until the
>pH gets up to about 6.5. Some of the wash solution selection depends on
>pipe assembly techniques (fitting), too.
>
> ... Bruce D. Bullough ...
> Sebesta Blomberg & Associates
> 2381 Rosegate
> Roseville, MN 55113
> 651-634-7344 (office)
> 651-634-7400 (FAX)
> www.sebesta.com
>
>
>-----Original Message-----
>From: Thomas Laupa [mailto:tlaupa@frii.com]
>Sent: Monday, May 20, 2002 10:59 AM
>To: PipingDesign@yahoogroups.com
>Subject: RE: [PipingDesign] Piping Systems for High Purity Deionized
>Water
>
>
>Bruce:
>
>per your recommendation, and some library work, looks like we'll use
>PVDF. what types of cleaning procedures would you suggest?
>
>
>At 08:00 AM 5/20/2002 -0500, you wrote:
> >"High Purity Water" is a relative term. At a certain point, PVC can
> >only serve after it's been leached (and therefore weakened). Go w/
> >resistoflex, PVDF or glass lined, but any need to be properly cleaned
> >and installed. Not all glass is even right (and everyone hates to fit
> >or pay for glass). Always be aware that ultra pure water is very
> >corrosive!
> >
> > ... Bruce D. Bullough ...
> > Sebesta Blomberg & Associates
> > 2381 Rosegate
> > Roseville, MN 55113
> > 651-634-7344 (office)
> > 651-634-7400 (FAX)
> > www.sebesta.com
> >
> >
> >-----Original Message-----
> >From: Thomas Laupa [mailto:tlaupa@frii.com]
> >Sent: Friday, May 17, 2002 3:03 PM
> >To: PipingDesign@yahoogroups.com
> >Subject: [PipingDesign] Piping Systems for High Purity Deionized Water
> >
> >
> >Gents:
> >
> >Have been given a project involving high purity water used for washing
> >integrated circuits. Looking for some advice:
> >
> >1>What piping systems are generally used? Existing system is a
> >hodgepodge
> >of PVDF and PVC.
> >2>Can anyone recommend standards or specifications?
> >3>Can anyone recommend good reference material?
> >
> >Thank you in advance for your help.
> >
> >
> >
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Received on Tue May 21 10:13:00 2002