add arrow-down arrow-left arrow-right arrow-up authorcheckmark clipboard combo comment delete discord dots drag-handle dropdown-arrow errorfacebook history inbox instagram issuelink lock markup-bbcode markup-html markup-pcpp markup-cyclingbuilder markup-plain-text markup-reddit menu pin radio-button save search settings share star-empty star-full star-half switch successtag twitch twitter user warningwattage weight youtube

Compression fitting fit clarification

kendiggy
  • 19 months ago

Working on my first rigid tubing build. Not entirely sure how to fit the compression fittings on the petc tubing. I have EK fluid gaming's aluminum fittings, they are 16mm OD 12mm ID, and 12/10mm tubing. There are 3 O-rings, one on the bottom threads (irrelevant to my question), another that goes on the tubing and the third stays inside the fitting. The third one, is the tubing supposed to fit inside the ring? I ask because it's a really, really tight fit even after using alcohol as a lubricant and I can't get it all the way in. Any other way and the tube just comes right out of the fitting.

Comments

  • 19 months ago
  • 1 point

Sounds like you have the wrong parts. The fittings and tube sizing should match up. So Fittings which at 16/12 will not work with 12/10 tubing.

I am assuming you have these fittings: https://www.ekfluidgaming.com/ek-hdc-alu-fitting-16mm

You need to purchase 16mm outer diameter tubing, can see it mentioned on their page: https://www.ekfluidgaming.com/ek-hdc-alu-fitting-16mm

The idea of compression fittings is the 16mm tubing has a snug fit against the wall of the 16mm fitting and the compression fitting with an O-ring clamps down and as the name suggests compress's.

TLDR you have the wrong tubing for the fittings. This is the tubing you need with those fittings: https://www.ekfluidgaming.com/ek-hd-petg-tube-12-16mm-500mm-2pcs

  • 19 months ago
  • 1 point

but isn't that the point though? 12mm outer diameter of the tubing fits snugly inside the 12mm inner diameter of the fitting? I have their 16/12 tubing as well and that also doesn't fit (ordered it originally, then got the 12/10 from a third party - faster shipping) edit - yes, those are the fittings I have

  • 19 months ago
  • 1 point

Not so much for compression, the inner diameter of the tubing does not matter for hard tubing with compression as the hold is made with the compression force hence the name. In fact most compression fittings do not have anything on the inside so you could actually use any size internal tubing as long as the outer tubing fits securely and the compression element locks on place. Is as you suggest the point is that 12mm outer diameter tubing should work with 16mm outer diameter tubing that is not the case. If you think about it, there would then be a gap around the tube and compression would be useless.

Those fittings and that tubing from EK should fit and work together. Use a bit of force but not excessive, and wet the oring.

Easiest way to check that the 12mm outer diameter tube will not work is out the compression element over the tube. You will literally see how loose it is.

  • 19 months ago
  • 1 point

I think you may be confused by the inner/outer diameter of this particular fitting. The outer diameter is largely irrelevant because the tubing goes inside the fitting, utilizing the 12mm inner diameter. The fact that they define the outer diameter is what mislead me to incorrectly purchase the 16/12 tubing in the first place. The 16mm tubing doesn't fit inside the fitting, the 12mm tubing does but it stops at the inner o-ring and i have to fight to get it past the o-ring. I'm of the school of thought that if it doesn't fit something is wrong so don't force it, so I don't want to fight too hard. Not sure if I'm doing something wrong or if maybe just sanding down the outside of the tubing will do the trick. I could try it, was hoping for a definitive answer here.

  • 19 months ago
  • 1 point

Tube may go inside which is normal of fittings, but how does the compression seal if there is a gap between the two.

Anyways best of luck. If its as you say, its weird. EK's own site lists the tubing to use as 16mm OD (see technical data on fittings page: https://www.ekfluidgaming.com/ek-hdc-alu-fitting-16mm) and all of my current builds use compression fittings with hard line tubing.

  • 19 months ago
  • 1 point

wow, I'm sorry, just realized that those are NOT the fittings I have. https://www.ekfluidgaming.com/ek-hdc-alu-fitting-12mm - these are. Sorry for making this so confusing...

  • 19 months ago
  • 1 point

https://photos.app.goo.gl/mDjJWUtywt1gweceA Here are some pictures of what I'm talking about. The first picture is the 16/12 tubing against the fitting, the second is the 12/10 tubing inside the fitting, the third is the problem I'm encountering. I'm not sure if you can tell in that picture, but the edge of the tubing will not go past the o-ring.

  • 19 months ago
  • 0 points

using alcohol as a lubricant

Just WTF man?

You lubricate your throat with alcohol, not your O-rings. If anything, it cleans them of the lubrication they came with. You use silicone-paste to lubricate your O-rings to make them last longer and the tubing slide in easier.

You should really watch some videos on how to build things before you start doing it.

Sort

add arrow-down arrow-left arrow-right arrow-up authorcheckmark clipboard combo comment delete discord dots drag-handle dropdown-arrow errorfacebook history inbox instagram issuelink lock markup-bbcode markup-html markup-pcpp markup-cyclingbuilder markup-plain-text markup-reddit menu pin radio-button save search settings share star-empty star-full star-half switch successtag twitch twitter user warningwattage weight youtube