A shiny Viega press fitting is almost too pretty to use where it can’t be seen, but that doesn’t mean you should hesitate to bury it.
It’s one of the most common questions we get: can MegaPress, ProPress and other fittings be used underground? The answer is yes. Viega press fittings are approved for underground installations, per Uniform Code and International Code listings.
Of course, local jurisdictions having authority (AHJ) always have the final say in approval, and installations must comply with all local codes. The product doesn’t necessarily require approval beforehand as it’s already an approved joining method per the listing and the code, which will reference the approved joining methods by referencing the standard and listing. However, it is always easier to check with your local AHJ in case there are amendments to the local code the prohibit such installation.
Incidentally, approval of the underground application is based upon performance testing conducted by NSF International, which includes withstanding pressure, temperature, water hammer, bending forces, torsion, temperature variation, vibration and vacuum.