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High purity DI water compatibility with Stainless Steel
Q. Hi,
I have read conflicting opinions on this matter. I am trying to find out if very high purity DI water as used in the semiconductor industry can cause corrosion or metal leaching problems with stainless steel. If so are there any high grade s.s. available that can resist corrosion ? If not, would some kind of polymer coatings (Teflon, PFA) help ? The DI water is contained in stainless steel container, heated and passed through stainless steel tubing.
Thanks.
Semiconductors - Santa Clara, California
2004
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A. Stainless steel is often used for pumps and heat exchangers for Types E-III and E-IV DI water (up to about 12 Meg-Ohm-cm). For 17-18 Meg-ohm-cm water, it is OK to use passivated or electropolished stainless steel as long as there is a tank of mixed bed ion exchange resin after the stainless to remove any dissolved metals. consultant - Cleveland Heights, Ohio 2004 A. Your worry is normally not the extent of the attack of the DI on the SS, but the amount of the SS that dissolves into the DI and spoils it for the intended use. For high grade DI, Teflon is the only answer. James Watts- Navarre, Florida 2004 |
A. DI water penetrates (316L & 304) SS with a rate of up to 20 mil/yr. For best results use 316L that is electropolished and passivated. However, this would not prevent ions leaching from S.S. Heat makes things worse.
Q. I would like to know or obtain a references about the rate and type of ions leaching from 316L S.S. specially at elevated temperature.
- Los Angeles, California
2005
Q. I have a pump that has some 17-4 Stainless Steel parts in it. We will be pumping Deionized water and have some concerns regarding the compatibility of the 17-4 Stainless Steel and the DI water.
Greg E Olson- Minneapolis, Minnesota
2006
Q. Hi
I have to ask about chemical compatibility of stainless steel 316L, and how long was 316 SS standing with specific chemical solution e.g halide solution and acidic solution.
What is pH and concentration and time?
regards,
medicare - Kota Bharu, Kelantan, Malaysia
2006
A. I found the following older article that addresses various materials and how they react to semiconductor grade pure water.
PURE MATERIALS - Water Quality and Materials of Construction: A water chemist's approach.
By Samuel J. Pengelly
ULTRAPURE WATER, May/June 1987
Pgs. 24 -32
The article references the trend to PVDF as the material of choice in semiconductor (this trend has already occurred).
- Los Angeles, California
January 12, 2010
A. Why not use PTFE or PVDF components instead of stainless steel? That's the way to circumvent the problem entirely.
H. MacPhee- Rijswijk, South Holland, the Netherlands
July 16, 2018
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