Viega 20673 ProPress 45° street elbow Smart Connect technology Copper, 3'' x 3''

P x FTG means one end is a press socket that slips over 3 inch copper tube, and the other end is a fitting-end (street) male spigot sized to drop into another 3 inch press socket or copper fitting cup. That is what makes it a street elbow: you can press it directly into the next fitting without adding a short stub of tube.

Yes. The 20673 is a 3 inch x 3 inch copper press fitting, and ProPress copper fittings press onto standard rigid copper tube in types K, L and M at the nominal size. Both ends are 3 inch, so the socket goes over 3 inch tube and the FTG end goes into a 3 inch cup.

Yes. 3 inch is above the range of standard compact press jaws. Sizes 2-1/2, 3 and 4 inch are pressed with a press ring and an actuator rather than a one-piece jaw, so plan the tooling before you take a 3 inch fitting to the job. Press ring and actuator are separate purchases, not supplied with the elbow.

Smart Connect is the feature built into the sealing element of ProPress fittings that intentionally leaks a small amount of water at an unpressed connection during pressure testing, so an installer can find the joint they missed before the wall closes up. On a 3 inch line with a 45 degree street elbow buried in a tight offset, that is the difference between finding the miss at test and finding it after drywall.