Viega 91720 MegaPress 90° elbow Smart Connect technology 316 stainless steel, 2'' x 2''

Both ends of the 91720 are press connections, listed as P1 x P2, in the 2 inch size. There is no threaded or grooved end on this fitting, so you press it onto 2 inch pipe at both the inlet and the outlet with a press tool and the correct 2 inch jaw or ring.

No. MegaPress fittings in this line press onto steel pipe, and the 91720 is a 2 inch press by press stainless body. Copper tube takes a ProPress copper fitting and PEX takes a PureFlow press fitting, so switching material means switching fitting system, not just adapting the end.

The 91720 is made of 316 stainless steel, which is the grade you specify when the line or the environment is corrosive and plain carbon steel would rust out. Carbon steel MegaPress bodies cost less and are common on dry fire protection, compressed air, and black iron gas or hydronic lines, but on anything where moisture, washdown, or chemical exposure is in play, 316 is the material call. Both press the same way, so the decision is about the media and the environment, not the install method.

Smart Connect is Viega's unpressed-connection feature: if a joint gets missed during pressing, the fitting leaks visibly at low test pressure so you find it during pressure test rather than after the walls are closed. On a 2 inch stainless 90 it matters, because a single skipped press on a run that size is an expensive callback.

The elbow ships as a complete pressed fitting with its sealing element in place at both ends, so there is no separate gasket or nut to order. What you supply is the 2 inch pipe, a proper square cut with the burr removed, insertion depth marked, and the press tool with 2 inch tooling.