Stainless Steel

In the Composites industry, Methyl Ethyl Ketone Peroxide (MEKP) is widely used as a catalyst for many resin system and processes. It's manufacturers require any piping for the transport of, or working vessels for the use of MEKP, to be made of either 304 or 316 Stainless Steel.
No one here could give me a definitive answer (mostly all composite nerds) as to why these two exclusively are specified. Being an old "heat treater" myself, and having been thrust into the composite world only a short time ago, the steel man still in me needs a better answer.
Anyone ? TIA Tony Gaither

Heattg wrote:
  Quoted Text Here  
Both steels are quite simple - 304 beeing just primitive. It says: "All austenitic stainless steels are possible."
Michael Dahms

  Quoted Text Here  
Tony:
The manufacturers are very, very, worried about reaction between the MEKP and the pipe or vessel. You need to look at material safety data sheets (MSDS) from knowledgeable chemical suppliers. For example, see http://www.atofinachemicals.com/orgper/pdf/ketone.pdf
which under "Equipment" on page 5 says:
"Recommended materials of construction - 304 and 316 stainless, Teflon, Nylon, Kynar and Kel-F"
"Avoid materials such as copper, brass, mild steel, aluminum alloys, natural and synthetic rubbers".
For scary safety info regarding reactivity and need for venting, look at CCOHS:
http://www.ccohs.ca/oshanswers/prevention/orgperox.html#_1_7
Pittsburgh Pete ________________________________________________________
DISCLAIMER
We don't believe what we write, and neither should you. Information furnished to you is for topical (external) use only. This information may not be worth any more than either a groundhog turd, or what you paid for it (nothing). The author may not even have been either sane or sober when he wrote it down. Don't worry, be happy.

Thanks to all.
I knew MEKP had positive reactions to quite a few metals and metallic compounds. I had surmised that the relative "inertness" of these two particular items were probable reasoning, but I still needed an answer from "steel" people.
Tony Gaither