No. The flanges are strictly cosmetic. If the penetration in the finished surface needs to be watertight, you will need to use an approved silicone product for application.
Does Dearborn Brass/Oatey offer any shower conversion products for a claw foot (tub on legs) bathtub?
You can easily transform the claw foot tub into a tub and shower with #R100 Kit. View the components in the kit.
What types of sinks can a Sink Hole Cover be installed on, and does it create a water tight seal?
The Sink Hole Cover can be used with any sink application when an extra hole on the faucet deck needs to be covered. The Sink Hole Cover will not achieve a watertight seal on its own, and an approved silicone product will have to be applied in-between the sink surface and the Sink Hole Cover.