A sprinkler assembly includes a connection fitting and a fire protection sprinkler. The connection fitting includes a tubular member with a first insertion end and a second insertion end with an internal conduit extending between the first and second insertion end along a longitudinal axis, the tubular member including an exterior surface and an inner surface, the inner surface defining a sealing surface between the first and second insertion ends circumscribed about the longitudinal axis and including a gripping portion axially spaced from the sealing surface. The fire protection sprinkler has a body defining an inlet and an outlet, a deflector spaced from the outlet, the body having an outer encasing surface surrounding the longitudinal axis and including a leading portion and a trailing portion for insertion in the second insertion end with the leading portion received within the sealing surface before the trailing portion engages the gripping portion.