Putting the valve in the bottom would tend to attract dirt and grit, and possibly fail a little earlier.

Glue a piece of vinyl tubing into the side of the bag as a spot to attach a purge valve.

Cut a small horizontal slit in the side of the drybag--a 1/2" slit should work for 3/8" tubing. Slide the tubing in so it rests vertically against the drybag. Glue around the slit with Aquaseal. Glue the bottom of the tube to the inside of the bag, and a short section of the upper part of the tube to the outside of the bag. This will keep the tube lying flat against the bag and out of the way.

Shawn

: Evan;
: I'd be happy to send you some. I'm sure I have lots.
: I'm trying to mount one in the bottom of a store bought nylon pvc coated dry
: bag so I can purge the air out after filling with stuff.
: Not much luck so far.
: Email me an address and I'll send you some in an envelope.
: If I can't fit a valve to a dry bag then I will have to build from scratch
: with heat seal nylon which I don't have yet. I think there is a supplier
: in Calgary.
: Terry