No registration, no passwords; no pop-up ads -- just aloha, fun, & authoritative answers.
As an eBay Partner & Amazon Affiliate we receive compensation for qualifying purchases.
Home /
T.O.C.
FAQs
 
Good
Books
Ref.
Libr.
Advertise
Here
Help
Wanted
Current
Q&A's
Search 🔍
the Site
pub  Where the world gathers for
plating, anodizing, & finishing Q&As since 1989





-----

Pitting Corrosion in Domestic Hot Water Heaters in Greece





The domestic hot water system was affected fairly uniform with pitting corrosion. A Reverse osmosis plant is equipped (sea water) for preparation of desalinated water, which is then mixed with fresh water for domestic purposes.

Do you believe that the use of stainless steel 316 was the correct selection taking into consideration the following:

Temperature
PRE (pitting resistance equivalent)

iS IT POSSIBLE TO HAVE PITTING CORROSION EVEN AT NORMAL pH (7.5)

CHRYSANTHOS CHRYSANTHOU
LCL - Athens, Greece
2001



Dear Crysanthos

For your first question I would say about the kind of SS 316 is the right choice but not the best, I recommended 316L(14435 german number)with his higher resistance against seawater. And second you have to passivate all surfaces that have bean treated with welding grinding etc. Because I know how my homeland fellows works and that is something they never do and I am 99% sure that this is the solution of your problem.

Athanassiadis Stelios
Passivation Greece SA - Thessaloniki
2001



I experienced deep pitting corrosion on type304 stainless steel twice last year. One is under fresh water use, and another one is sea water use. Both cases were finally supposed being occurred by deposit formation on the surface of stainless steel. And I verified that reason was correct by lab testings. In the testings, 316 showed better resistance tendency than 304, and 316L showed better than 316L Although better materials are more expensive.

Any stainless steels should be susceptible for pitting by deposit formation. The important thing to use such materials sound in likely possible in deposit formation is to avoid stagnant region in the system. Of course, it is much better to eliminate debris in the stream.

Hiromi Kawaguchi
- Tokyo, Japan
2001


Perhaps you should consider using epoxy vinyl ester resin to be used in the construction of the inner tank.

Dawie Thirion
- Cape Town, RSA
2004




(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

 
Jobshops
Capital
Equipment
Chemicals &
Consumables
Consult'g, Train'g
& Software


About/Contact  -  Privacy Policy  -  ©1995-2024 finishing.com, Pine Beach, New Jersey, USA  -  about "affil links"