Thu May 24, 2018 4:11 pm
If you are using a small compressor, say 2 to 5 cfm, I don't see a problem with a 1.75" outside diameter filter cartridge. You should only have about a 1/8" gap between the tower inner wall and the outside of the cartridge. Should be able to engineer something simple that would do the job. For example a 1/8" cross section oring of the right diameter might push into place and effectively seal the cartridge to the container, but you need some way to be sure the oring can't get out of position. For a quick example obtain or machine a couple of tubular plastic sleeves of the appropriate diameter to allow them to go over the cartridge, One goes over cartridge bottom, and is long enough to come up within a inch (just picking a number for example). Then the oring goes into place above that sleeve, followed by a short sleeve of appropriate length to retain the oring with your top plug/lid in place. You would need to make sure the fit of the oring is appropriate to make a sure seal between the cartridge and container wall.
Other methods I have used include fabricating a tube to go into inlet at inside of bottom plug of filter tower, and the upper end is exact size to seal into or onto the filter cartridge female or male end. (most of those will have internal or external oring seals at cartridge inlet end). Some machining is typically required to get this right.
Some photos of your filter tower ends, inside and out, would be helpful to generate some more ideas. Look forward to hearing from you.
The older I get the better I was.