Use of gasketed locknuts

[Esaul]

When using gasketed locknuts to prevent water from entering an enclosure can one be used either inside or out or must 2 be used. Where would this be addressed in the code?

 

[Volta]

Looks like one will do it. It would not be in the NEC, but rather part of the listing of the locknuts.

Sealing (Liquid-tight) Locknuts ? Sealing locknuts are intended for use with threaded rigid metal conduit and intermediate metal conduit with one sealing locknut in the outside or the inside and either an ordinary locknut or sealing locknut on the inside of the enclosure for wet locations or liquid-tight applications. Sealing locknuts may also be used with Listed wet location or liquid-tight fittings where so marked on the fitting carton and used on the inside of the enclosure.