A few years ago we made some Wiggins couplings for water plumbing.
These are widely used in airliners and military aircraft as well as Formula 1 race cars. They are highly reliable, long lasting  and quick to take apart. They must be tig welded to aluminum tube. If you buy the race car versions they are about $100 each. We simplified them by doing away with the outer trick clamp and used a mundane hose clamp instead. We also standardize on 1.5 inch OD aluminum tubing for water plumbing. That would be the only size we would make.

We are thinking of making another batch but we would need to make at least 50 sets. Is anybody interesting in buying some of these? My guess is they would be half the price or about $50 a set.

Paul Lamar