Patent ID: 7240688

Claim:
A method for retrofitting a fire hydrant with a secondary valve comprising: (a) selecting a hydrant, which has been installed in a water supply system and is in service in the system, the hydrant comprising an outlet, an interior cavity and a primary valve; (b) temporarily removing a portion of the hydrant to allow access to the interior cavity for conducting the retrofitting; (c) installing a secondary valve in the interior cavity of the hydrant between the primary valve and the outlet, the secondary valve adapted to cooperate with an insert to form a secondary valve, the secondary valve adapted to prevent fluid flowing toward the primary valve; (d) installing an insert in the interior cavity of the hydrant between the primary valve and the outlet, the insert comprising a seat adapted to fit with the secondary valve in a substantially fluid tight relationship, and an elongated portion for positioning the seat at a desired position in the interior cavity of the hydrant; and (e) reconnecting the portion of the hydrant that was temporarily removed, or connecting corresponding structure, to restore the hydrant to service.