I started on this P valve a several months ago but never finished it.
Off to the Lermi in a few days and I want to take my backup drysuit just in case so I thought I better add a P valve.
Very simple design that uses an Apeks cuff dump. There is no valve to open or close and no bolt to lose.
Currently its unbalanced but easy enough to add a T piece and check valve ( if I can find one small enough) or a duckbill check vale in the main body if I can source one. But to be honest Im not convince balanced is really required.
If anyone wants one of these and has a cuff dump sitting around let me know.