The whole thing is dishwasher safe except for the sealing-ring and overpressure plug. I've run the top and bottom through many times (and have even run the sealing ring through a couple times on the top rack when it was starting to smell like aromatics and alliums). It's a solid unit. Just pop the ring and plug out, and dishwasher-away!
Here's the link to the product page, which has the specs and manual (which contains a bunch of recipes and guidelines, if you're new to pressure cooking... which I don't think you are).
In related news, I miss having a dishwasher.
