We could not find any reference to grooved joints in piping in NFPA 14.
Are they allowed as a piping joining method in non-sprinkler protected spaces?
[R M Arsenault Engineering Inc. www.rmae.ca]
NFPA 14-2013 4.4.3 Groove Joining Methods
184.108.40.206 Pipes joined by grooved fittings shall be joined by a listed combination of fittings, gaskets and grooves.
Good to go.
Above is a snippet.