Viega 84890 MegaPress 90° street elbow Smart Connect technology Carbon steel, 1-1/4'' x 1-1/4''

The 84890 is a carbon steel MegaPress fitting, which is the material family made for black iron and carbon steel pipe systems rather than copper. Size is 1-1/4 inch on both ends, so it presses onto 1-1/4 inch carbon steel pipe. For copper tube you need a copper press fitting instead, not this one.

No. MegaPress carbon steel fittings are a press connection, so the 1-1/4 inch pipe end gets cut, deburred and marked, then pressed with the matching jaw. No threading, no cutting oil, no hot work permit for the joint itself. You do need the correct press tool and 1-1/4 inch MegaPress jaw, which is not supplied with the fitting.

Smart Connect is Viega's feature that leaves an unpressed connection deliberately leaking during pressure test, so an installer can spot a joint that was missed before the system is buttoned up. On a 1-1/4 inch carbon steel line with a dozen joints behind a wall, that's the difference between finding the miss at test and finding it after drywall.

Use the street version, like the 84890, when the turn happens right at another fitting: its FTG spigot end slips into that fitting's press socket, so you skip the stub of pipe and one extra press joint. Use a P x P elbow when the 90 falls in the middle of a pipe run with tube on both sides. Fewer joints in a tight mechanical room is usually the reason to pick street.