Compression fitting and tube removal

[Teenyman45]

Recently, I tried to do a test fitting with some 3/8id 1/2od tygon tubing and a similarly sized Swiftech Lok-Seal compression fitting. The tube required some effort to go on, but I did not need to warm it first.

I then began hand-screwing the cap back onto the base. I got as far as having two exposed revolutions worth of threading before I could turn no further. Is this normal or did I mis-thread it?

I was also unable to remove the cap by hand-unscrewing... so what method do people use to remove the caps without damaging them? I was going to use a 13mm hex wrench with a paper towel or a sheet of two-ply to act as a buffer/ cushion and prevent scratching or is there a better method?

 

[Crispy002]

Screw until it's tight by hand, they're not meant to be threaded all the way. Further tightening can strip the threads, or worse, tear the tubing causing a leak.

 

[featsdontfailme]

Aren't the lok-seal fittings flat on two sides?

I generally use a needle nose plier with rubber tubing slid over the jaws to reduce injury.

Unfortunately, you can't help but slip and marr the metal. It's generally pretty soft brass.

 

[Tsumi]

Usually, tightening it in by hand is all you need for compression fittings. To test it, just try to pull the tubing out from the fitting. If you can't pull it out, it's more than secure enough.

 

[Teenyman45]

Aren't the lok-seal fittings flat on two sides?

I generally use a needle nose plier with rubber tubing slid over the jaws to reduce injury.

Unfortunately, you can't help but slip and marr the metal. It's generally pretty soft brass.

The stated design goals with this brand of compression fittings were that 1) it was supposed to be "lok"-ed into place against the block/pump/whatever with a wrench; 2) that it required very little wrenching to ensure a firm seal against the block; and 3) that the finish would be more likely to survive having a wrench applied to it. The screws on my three new radiators are all copper as part of the pure copper design motif for the brand.

Usually, tightening it in by hand is all you need for compression fittings. To test it, just try to pull the tubing out from the fitting. If you can't pull it out, it's more than secure enough.

Oh it definitely would not yank free. After a significant humidity change in the living room, I was able to unscrew the cap. The tubing itself could only then be pulled free by first running it under hot water. The underlying barb is fine. The screw threads past the barb had a small amount of black finish removed by the cap's screw threads, so I will need to use a bit of cushioning once I actually begin assembling my loop.

Tangent: after a week's delay, NCIX has finally figured out how to process a credit card and then once that was done figured out in only half a week how package and ship my order so I can hopefully begin the picture taking and loop assembly process this weekend.

 

[featsdontfailme]

OK.

But what I'm referring to is this: http://www.swiftech.com/lok-seal.aspx

The lok-seal fitting's outer ring is different than other compressions, in that it has opposing flat sides; rather than being all rounded. That's so you CAN tighten the ring down with a wrench.

I'm not sure if Swiftech includes a spanner in the purchase. If not a simple plier applied to the flat sides should be able to tighten the ring securely without marring the finish.

The white paper on these fittings is in this thread: http://hardforum.com/showthread.php?t=1686384&highlight=swiftech+lok-seal

 

[Teenyman45]

Each fitting comes in its own little plastic polyhedron with a square label that looks like it was hand cut and printed off of a home color inkjet and comes with nothing else. There is no free spanner/wrench, but these fittings (at least in the size I bought) are about $1 or more cheaper per fitting than most of the other name brands out there. With 18 fittings, 2 45 degree bends, and 2 short male to female extenders that adds up to a good bit of savings. The shipping charges were also negligible because it was shipped with a 7970 komodo blocks and a komodo tri-fire bridge.

The hex shape is for tightening the fitting to the block and not so much for tightening the cap which is screwed over the tube and back onto the fitting. The flats, particularly on 1/2od fittings are really, really tiny and have the swiftech logo painted on them. Even though the shape is more conducive to tool use, it looks like gripping the flats with a tool will probably strip off or mar the logo if there is no cushion between the cap and the tool.