Two pressure cooker questions

HI all.
Just wondering if any knowledgeable cooks out there cook corned beef and also beetroot in their pressure cookers.this is a whole new game to me as I only purchased my new toy a couple of days ago.i did beetroot this afternoon which turned out very well.i cooked it at low pressure, covered in water for 45 minutes for three globe beetroot.Does this sound about right?i'm doing corned beef tomorrow the way the book that came with my cooker said to do it.That is, high pressure for 55 minutes.however, it only has two cups of water and the meat sits on a trivet.i'll be putting my usual vinegar, brown sugar and peppercorns in as well.Just wondering how others have found cooking these particular items.my cooker is a digital one, but I don't think that should make any difference.Sorry for the somewhat rambling thread.lol!
Cheers

Hi there. I cook beetroot in my pressure cooker at high pressure for 15 minutes only and put the pressure cooker under cold running water to reduce the pressure quickly and stop the beetroot cooking. Corned silverside I cook at high pressure for about 30 minutes (sit meat on trivet). Use only 2 cups of water, (never less) 1 tbsp vinegar, peppercorns and 1 onion.Oh and let the meat cool down while still in the liquid (it absorbs more flavour) and use the liquid to make mustard sauce.

I do as Melford does.Mind you, my pressure cooker is 50 plus years old (was Mum's) and I don't have a pressure control.

Thanks so much for the replies.i'm sure I'll get a lot of use out of it.
cheers