Is this a DOT-approved compression union for brake systems?

Pulled from my thread here (http://www.automotiveforums.com/vbulletin/showthread.php?t=578324).

Take a look at these pics:

http://www.chicagophoto.net/JeffStuff/1991.Oldsmobile.98.BrakeHardware1.jpg

http://www.chicagophoto.net/JeffStuff/1991.Oldsmobile.98.BrakeHardware2.jpg

The top upper left fitting is a brass double-flare union I picked up at Lee Auto Parts. That's standard stuff: cut two lines, double-flare them with fittings and connect them up. Probably makes a good connection, but there seems to be some debate regarding the use of brass in braking systems?

The top two upper right fittings are what's needed to adapt the large GM bubble-flared fitting. It adapts to a female double-flared fitting and will accept standard double-flared lines/fittings. No one seems to understand the purpose of these GM fittings, and no one has pre-flared bubble line with these fittings either. Even a reputable local GM parts/dealership was of no help with this.

The bottom two fittings are interesting. According to NAPA, these are DOT-approved compression unions for use in brake lines. The general consensus out there is that compression unions are a big no-no in braking systems. They convinced me though, and I bought a few. The top one is one I opened up; you can see that they do differ in design from the typical compression union found in water supply systems (household plumbing). On the left, I took out the compression ring and hand tightened the nut down; I imagine this is closer to how it will appear with an actual line in and the ring/nut tightened down. The bottom one shows what they look like as purchased from the store and hand tightened with compression ring inside.

Also, when I stopped by an AutoZone on the way home and asked them about brake compression fittings, they showed me a brass one like that found in household plumbing.

So, do you all think this DOT-approved compression union is the real deal?

IMO a compression brake fitting is like a plumbing compression fitting; it's an easy, convenient way to do a specialised or temporary installation.

I have found compression fittings elsewhere to be temporary; they often loosen or leak over time.
IMO brake fittings should be flared wherever possible, and a compression fitting to be avoided, regardless of any DOT (possibly counterfiet??) rating.

Finally, I have often used brass unions in braking systems with no problems. As far as I know, the brass is fine (please correct me if I am wrong on this); it's the copper pieces that are weak and hazardous.

I'v seen brass parts used many times, and copper parts (parts, not lines) used without problems also.