I'm putting together a fountain feature in my yard and I'm using vinyl tubing from the pump to the bottom of the feature (which has a copper tube inside). I've got a compression union to connect the two, and I'm pretty sure it'll work fine on the copper side. But on the vinyl side everything I see indicates that I should use a plastic sleeve on the outside of the tube inside the compression nut.

In this case, however, the fitting that I picked up has captured brass sleeves (by which I mean that they're attached to the nut, not a separate piece).

Is this likely to damage my tubing? Should I pick up a different fitting or can I just be extra careful about over tightening?

  • I used brass ferrule compression with vinyl tubing quite often and they work well. The only problem I have found is once compressed you have to cut the tubing to replace them. I never have blow outs with brass like I did with the plastic ones.
    – Ed Beal
    May 1, 2016 at 14:20
  • Awesome, thanks. I'll give it a whirl and see how it goes.
    – cori
    May 1, 2016 at 14:58
  • I have also done this in an industrial application for pressure taps. It seems to work well in a non-critical application.
    – Joel Keene
    May 3, 2016 at 19:11

1 Answer 1


To get a good "squeeze" when using a brass ferrule on plastic tubing, without collapsing the tube, you should be using a tubing insert:

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