How to choose the most suitable materials? 1

[dangchung]

Hi all,
I want to ask about the chemical resistance, I saw an online tool (link:

https://phutungbom.com/kha-nang-khang-hoa-chat-cua-vat-lieu-bom-mang)

showing the resistance of Santoprene against hexyl alcohol is only B-rating, and it is A-rating for Teflon.
However, when I tried to ask an AODD pump salesman, he told me that I have to use A-rating materials.
Is it correct?
When I read a chemical resistance guide, there is a paragraph like this: "Neoprene or Wil-Flex™ diaphragms should generally be used unless the chart shows them to be unsatisfactory. Even though Buna-N, Nordel®, and Viton® may show “A” ratings, if neoprene or WilFlex™ have at least a “B” rating, it will probably be the most economical choice on a “cost of diaphragms per gallon pumped” basis."
So what should I choose?
Thanks.

 

[GregLocock]

That depends on the application. If maintenance or failure is mission critical, go for A. If cost is important then B might be better. If all these issues were obvious we wouldn't need brains, just salesmen.

Cheers

Greg Locock


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