Safely reusing a friend's Medela Pump
This may be of interest: I was prepping for our new baby when I stumbled on how to safely reuse a Medela pump. We had an Ameda Purely Yours pump that had broken and a friend gave us their old Medela Pump-In-Style.
After much googling on how to sanitize the Medela, seeing all the dire warnings, and taking it apart anyway I finally noticed the obvious. The Ameda tubing is the same size as the Medela tubing...or at least close enough that it fit into the Medela face plate and worked.
The Ameda system is a closed system where there is complete air separation from the pump and the breast shield unlike the Medela where milk can travel up the tube and onto the pump diaphragm. Closed systems are considered safe to reuse. Open systems, not so much. Because there is no air transfer between the two sections in the Ameda design there is no risk of cross contamination even from airborne pathogens...at least according to Ameda. :)
You can buy the Ameda part replacement kit from amazon. It doubles as a manual pump.
Note: I've only tried with our old Ameda parts and the 2008 PIS we were given. Your Mileage May Vary. Your warranty will certainly be voided if they ever find out.
It would be useful for some pros with access to more pump models and tubing to see how many models might be safely reused in this way. Engineering wise I don't see any cross contamination risk vectors unless the Ameda diaphragm tears (unlikely). In that case you'd probably want to toss that batch but that would be true in a used Ameda pump as well.
The details and research are on my blog.
Obligatory Disclaimer: I am not a doctor nor breast pump engineer. Do not rely on this post for medical advice. I am only describing what we choose to do for our baby.