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Substitution of stainless or aluminum for plated steel grating

2004

A sewage treatment plant has specified carbon steel grating with a electroless nickel plating to cope with DI water corrosion. The cost is prohibitive. The grating will only have incidental contact with the DI water, not submersion or containment.

I am proposing either stainless (304SS or 316SS low carbon) or aluminum grating instead. What are my pitfalls? The 304SS cost is 40% less, and the aluminum grating is less than half of the plated carbon steel.

Further, the electroless plating process is extremely slow and will cause serious delays, not to mention a lack of competitive sources. Comments?

Michael Seidelhuber
project manager - Hayward, California, USA

I don't think the aluminum grating will look good for long; aluminum gets dirty and stays dirty. The stainless will probably be okay but should ideally be electropolished. Vinyl ester fiberglass grating will be completely resistant to anything it will likely be exposed to and will give you the greatest assurance of being trouble free unless there is some special loading or abrasion situation that precludes it.

Electroless nickel plated probably would have been fine, and I'm sure there are many shops that could plate it for you in short order, but indeed it could be prohibitively expensive.

These are guesses, though, not based on actual application history in a sewerage treatment plant; some feedback from actual experience would go a long way.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2004

Michael,

What Ted said makes eminent sense ... but if people are walking on these FRP gratings, get one with a sanded top to reduce slipperiness.

Vinylester is a super choice but if there are only acid conditions, you could use a Polyester.

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).
2004

I installed grating like you in an industrial effluent treatment plant and the material was carbon steel hot deep galvanized and it is give a very good results.

Ahmed Fahmy
- Helwan, Cairo, Egypt
2004

The responses so far are well taken, however, my opinion about fiberglass grating, galvanized grating, and any coated or plated grating is that any scratch or scrape will open the core metal to corrosion. In the forty years I've been associated with building treatment plants, metals that can oxidize themselves after damage will prevent corrosion in the long term. Further, aluminum is 1/3rd the weight of steel or stainless steel and can be easily handled. The best option in the given situation is aluminum grating.

Michael J. Seidelhuber
grating manufacturer - Hayward, California, USA
2004