Viega 26745 MegaPress reducer Smart Connect technology Carbon steel, 4'' x 2''

The 26745 is an FTG x P reducer: the FTG end is fitting-sized so it slips into the socket of another 4 inch MegaPress fitting, while the P end is a press socket that receives 2 inch pipe. So it is not a pipe-to-pipe coupling on both sides. You need a mating 4 inch MegaPress fitting or socket on the FTG side, and 2 inch carbon steel pipe on the press side, then press each connection with the jaw matched to that size.

No. This reducer is carbon steel and is made for black iron and carbon steel pipe systems. For copper you need a copper press fitting system, and for stainless you need a stainless press fitting. Putting a carbon steel press fitting on copper or stainless mixes metals and is outside what the fitting is built for.

Smart Connect is a feature of the MegaPress sealing element that leaves an unpressed connection intentionally leaky during test, so a joint you skipped shows itself during pressure testing instead of after the ceiling is closed. On a 4 inch by 2 inch reducer with two separate press points, that matters: it is an easy fitting to press on one end and forget the other.

It is the choice when you cannot get hot work permits or cannot shut down long enough for welding. A press reduction goes together cold in seconds per joint versus cutting, threading and doping, or welding and inspecting. Where you would still weld or thread: systems outside what the MegaPress carbon steel line is rated to carry, and anywhere a specification calls out welded joints outright. Also note this one reduces 4 inch to 2 inch in a single fitting, so you are not stacking bushings.

Yes, and it catches crews out. The reducer has a 2 inch press socket on one end and a 4 inch fitting end that gets pressed into the mating 4 inch fitting, so you need tooling covering both sizes on site. Large-diameter MegaPress sizes use a press ring and actuator rather than a standard jaw, so confirm you have that ring before the truck leaves.