I have yet to find a -10 an to 5/8 tube compression fitting that's rated for more then 55 psi. has anymone? or at that pressure is everything going to be flared or welded?
http://www.mcmaster.com/#5220k46/=vy7a7s
For Tube OD 5/8"
Pipe Size 1/2
Pressure Rating
Maximum psi @ 72° F 650
For Tube Wall Thickness 0.035"
Temperature Range –65° to 250° F
Tubing Use with copper, aluminum, firm and hard polypropylene, polyethylene, and nylon
Additional Specifications Straight Adapters, Tube-to-Female Threaded Pipe
Easy-Align
RoHS Compliant
Also known as flareless fittings, these brass fittings are the most commonly used compression tube fitting. They are UL listed for flammable liquids, and can also be used with air, water, oil, and drinking water (where noted).
Easy-align fittings have a sleeve built into the nut, so they are always positioned for correct installation. They do not have to be disassembled to install and can be used on plastic tubing without changing the sleeve material.
Connections: Compression or NPTF (Dryseal) threads, which are compatible with NPT threads.