Hi, I recently filed a claim with my insurance company due to the compression fitting to a claw foot bath tub giving way in the crawl space. There was over $20K of damage to flooring and subfloor. The was a 1/2" copper supply line that terminated with a 90 vertical elbow and a short riser of 3" copper with a 1/2" threaded mail copper fitting. The 1/2" threaded mail fitting is about 4" below the subfloor. The 1/2" chrome tube from the tub was then connected to the threaded fitting via a chrome compression nut, cone washer and brass ring washer.

My question; Due to whatever reason for the compression fitting failing or being pulled away from the 1/2" chrome tubing (to much pressure, someone tampered with it, ???) could there be sufficient water pressure to push or blow the rubber cone washer through the hole of the compression nut with it still being screwed to the 1/2" copper fitting?

The insurance company has paid for damages but this is something that I just cannot quite bind my mind around how I found the rubber cone on the ground and the compression nut still screwed to the fitting.

Can you post a pic of the rubber cone washer thing. With a compression fitting, it shouldn't be there. Use go advanced/manage attachments.

I was wrong on the copper supply which is more like 3/4" and the compression nut is for 3/8". Setup is like 3rd from top at Supply line installation tips for old bathtubs (http://www.oldtub.com/supply_line_installation.htm). tgcase

From an engineering standpoint, the method seems bogus at best. I do think the rubber gasket can slip through.

I definitely don't call it safe.

Why can't a real compression fitting and ferrule be used?

Using Compression Fittings - ManageMyLife.com (http://www.managemylife.com/mmh/articles/authored/using-compression-fittings)

Thanks, checked your URL and will definitely replace the fittings.

Some useful info:

Use nylon ferrules for plastic supply lines.
There is a ferrule removal tool available.