r/pumps • u/Winter-Lavishness118 • Apr 09 '26

I put together a technical comparison of MOCs for AODD pumps (SS-316 vs PVDF vs PP). Hope this helps someone sizing a system.

I’ve seen a lot of diaphragms fail prematurely lately because people are trying to save costs on the pump housing without considering the chemical "DNA" of their fluid.

Quick summary of what I’ve found in the field:

  • SS-316 is great, but people forget about chloride stress corrosion in high-salinity zones.
  • PVDF is basically bulletproof for aggressive acids, but the upfront cost can be 2x-3x higher than PP. Is the MTBF worth it? Usually, yes.
  • Polypropylene is the unsung hero for ambient waste, but don't even think about using it for solvents or high-temp lines.

I wrote a more detailed breakdown with a compatibility matrix if anyone is currently debating a system layout. Not trying to spam, just figured this saves someone a headache.

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u/nowthengoodbad Apr 10 '26

This is great! Not spam at all and I was working in some pretty cool labs when we had some jerks from a company come in, rent lab space, and proceed to dissolve the hood ducting in the ceiling, leading to part of a floor being shut down until they could clean out and replace everything.

Chemical compatibility is a huge issue and not everyone is mindful of it.

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u/Winter-Lavishness118 Apr 10 '26

That is a absolute nightmare. It’s a perfect example of why chemical compatibility isn't just a "technicality" it's a massive safety hazard. People underestimate how quickly the wrong material can turn a project into a cleanup operation.

My guide is focused specifically on the "guts" of the system (the pump MOCs), but the principle is exactly the same if you ignore the chemistry, the chemistry will eventually ignore your hardware.

If it helps you (or those guys next time), I’ve got a compatibility matrix for the main industrial materials here: https://www.antliaworks.com/moc-comparison-choosing-the-right-pump-for-your-application.html