I was doing a project a few days ago, and used some plastic drums, for a water storage system, we took three drums and wanted to leave them sealed,
in the past I have used bulk head fittings that one had a "Nut" on the back side that need to be tightened up to seal the washer,
I ran across these on a net search, called a "Uniseal" which is a rubber garment that one uses a hole saw to cut the correct size of hole, and put in the Uniseal and put the pipe in the uniseal, a leak free seal in my situation,
I used 1" and 3/4" I used 5 one inch units and three 3/4 using PVC plastic pipe in the seals,
there low cost, I found them as easy to use if the pipe and tank is properly prepared,
some possible sources of them, there are many more out there, may be even your own hardware store,
http://www.tank-depot.com/product.aspx?id=161
http://www.boatdepot.com/product.asp...Categor---=536
http://www.bulkreefsupply.com/store/...iseal&x=15&y=7
I was impressed with them, and did a good job for me in my situation,
U tube video on there use,
and just wanted to pass the info along,
I doubt they would work well in a pressurized system,
