Compression uses a ferrule or brass ring around the pipe that is compressed by the nut into the pipe and against the fitting. There is no such thing as Female Pipe Threads. There are Male and Female fittings, the pipe is the Male side and the fitting is Female. The Male goes inside of the Female. They both have pipe threads. Pipe thread, Compression, and Flare all have different thread pattern so that they cannot be mixed. They all do different jobs.
You may mean Qwest fittings. (yes, with a 'w' not a 'u') This is a range of plastic plumbing compression fittings to fit many different pipes. They have an 'O' ring and a gripper inside a large nut to tighten onto the pipe. -Very hot item when they came out 20 or so years ago, now a little old fashioned compared to Sharkbite and similar fittings.
NPT is a standard for threaded pipe and fittings. NPT stands for national pipe thread. NPT fittings are tapered thread fitting and usually rely on mechanical deformation in between the male and female fittings to create a seal in addition with teflon tape. Over tighteting may result in a leakage SAE O-ring fittings are straight fittings and rely on the O-ring to create the seal rather than deformation as in NPT fittings. Since these fittings do not depend on deformation chances of a broken fitting are virtually eliminated.
YOU thread or braze copper pipe Copper tubling you solder, braze, flaire, compression ring, mechincal joints
Compression fittings unscrew. Inside you will find an 'olive' (a thin copper ring) which is compressed onto the pipe to create a seal when the outer nut is tightened up. If you wish to replace the compression fitting then you may need to use a junior hacksaw to saw through & remove the olive - be careful not to cut into the pipe unless you wish to replace it too. As for the dishwasher I would guess that you could use the same fitting unless it is leaking. If it is leaking then replace the olive as above.
Did you put the ferrule on, the little brass ring?
Yes, pipe fittings can be designed to be compatible with metric pipe systems. These fittings are specifically sized to fit metric pipes, which are measured using the metric system (millimeters and centimeters) rather than the imperial system (inches). Make sure to confirm that the fittings are compatible with the specific metric pipe size you are working with before making a purchase.
What is actually broken the flnge ring rusted out and broke or the abs pipe? Abs pipe/flange broken: Use a ram bit to cut it out and install a new one. http://www.plumbingsupply.com/pvcsaver.html use a compression or expansion flange http://www.plumbingsupply.com/toiletflanges.html or just cut the pipe and put in a new one Flange ring rusted/broken: install a toilet flange repair ring or a spanner flange.
The lowest ring is the oil ring
There are compression ring and oil control ring
They are brass body fittings containing an 'O' ring and a serrated steel gripper ( the shark's mouth) at each end. They are excellent for joining different types of water pipe. I use all types of them and the can even join different sizes, -1/2 to 3/4 for instance.
HDPE pipe can use a rubber ring, if the rubber ring is properly sealed with a steel gasket. The rubber ring must be placed in a groove in the pipe and then the steel gasket is placed on top of it.