Leaky Needle Valve - Crap Fittings?

[madmattie]

I'm a noob, so maybe I'm doing it wrong. Here's my build:

full rig 2.jpg

I'm using this Watts valve:

front.jpg

full.jpg

I can't seem to get this valve to tighten to my 1/4" OD copper tubing. Given my setup, there is some strain on the valve itself as it's holding up the liebig condenser. However, I can't even tighten the damn value to any 1/4" OD tube!

Most compression fittings I've seen look like this:

compression.jpg

From what I can tell, these types of fittings work by compressing the ring to the threaded connector, which only works because the ring doesn't let the tube slip through. If the ring let's the tube slip, then you can just pull the tube out regardless of how tight the nut is screwed on.

The Watts valve has "Ander-lign Brass Nuts and Brass Inserts":

detail.jpg

I don't see how these fittings apply any pressure to the copper. In fact, the copper doesn't even slip all the way through the nut:

no slide through.jpg

Are these fittings just complete shit or am I doing it wrong?

Thanks for your help.