I have attached a link to a photo to show what it looks like. The assembly in the photo is a 4 inch sched. 40 PVC pipe with a cap at the bottom and a screw cleanout at the top. I tapped the side of the top of the tube for the output of the regulator. The best thing so far to seal the spout is a special bottle, filled with water, made from a ball jar (see photo). It keeps the tube clear of dried glue and you just have to flush out the water by pulling the trigger and waiting for the water to drain (followed by the glue). It takes anywhere from 20 to 40 lbs to force the glue out at a decent pace.
I have an aluminum hanger to hold the gun while I am gluing and an aluminum support for the ball jar all clamped with a hose clamp. Although you can't see it, I have a rubber grommet in the top of the ball jar that sort of seals the glue gun barrel when I am not using the gun. The tip of the gun is held in the water in the ball jar. I am hanging the assembly with a simple wire hanger that is attached (along with the regulator) by another hose clamp. I was looking for a simpler way of sealing the tip of the gun to keep the glue from drying, but so far caplugs and other approaches have limited success.
Any other improvement ideas would be welcome.
Here is the photo