SpudFiles

how exactly do you install them? do you just silde them over the pipe, and then tighten them down( not the ring, the other part).

also, whats the max psi one can handle? could they take 300psi?

You slide the pipe into it, then tighten the nut down until the rings bites into the pipe.
Markfh11q says they're rated to 750 psi; if you tighten the nut enough, I assume they could hold 300.

They won't hold 750psi if you follow the instructions given with them...

It usually says a half turn with a spanner after hand tightening it.

YEAH RIGHT.

I weld on the olives and then crank the nut on as tight as possible. I don't care what it says, a half turn is nothing I'd risk on my cannons.

well, if you didnt weld it, but you did crank it down as hard as possible how much would it hold?

Quite a bit, unless it cuts the pipe off. Try it out, experimenting is fun!

i heard that if you crank it too much it will hurt the olive? has this ever happened to you guys?

If you overcrank it then the pipe becomes visibly squeezed and the olive cannot be removed.

I'm not talking using a 12" spanner and a vice to wrench it til the nut can't physically move any closer to the rest of the fitting and the olive has been so squeezed into the pipe that the bore has halved but you'll know when it feels properly tightened and its not half a turn...

I also have a question. If the compression fitting leaks, what is the best way to stop the leak but still have it so you can take it apart again if you want to modify it?

silicone.

it worked for me.

Make sure it doesn't leak.

If it leaks then you've messed up something while putting it on.

Use fine sandpaper or wire wool to scrub the copper pipe, the olive (inside and outside) and the contact surfaces on the compression fitting where it will press against the olive.

That gives you the best chance of having a perfect seal when you assemble it all.

If it leaked it was'nt tightened enough and no they are not reusable

Yes they are.

You undo the nut and take it off. The olive might not be removeable but it's not important, thats why they're a couple of pence to buy.

This fittings are also called "Line Unions". I've used them on auto brake lins, hydrolic tractor lines, but never with air. I don't think scrubbing the "Ferrel/Olive" is a good idea, if you round the factory edge it will probly leak at that point. Snug down the "Flare Nuts", if it leaks, keep it pressureized then slightly tighten the Flare Nuts untill the leak stops.