Water freeze prevention valve

DETAILED DESCRIPTION It is accordingly an object of this invention to provide a device which furnishes completely dependable protection against freezing and consequent damage to water systems and the interiors of homes and other buildings.
It is another object to provide a water freeze prevention device which is automatically responsive to ambient temperatures that are at and near the freezing temperature of water.
It is still another object to provide a water freeze prevention device that is sensitive both to the ambient temperature and to the temperature of the water system in order to minimize the amount of water that must be wasted to prevent freezing of the water system.
It is an additional object to provide a water freeze prevention device that does not require venting of air during operation thereof.
It is a further object to provide a water freeze prevention device that derives its motive force entirely from the freezing of water within the device.
It is a still further object to provide a water freeze prevention device that is not subject to failure because of failure of o-rings, seals, or threaded connections.
It is still another object to provide a steam-actuating freeze prevention valve that is automatically operable during freezing weather and inoperable during above-freezing weather.
In accordance with these objects and the principles of this invention, it has surprisingly been discovered that the freezing of water can be utilized as the sole source of power for opening a relief valve which is connected to a water or steam system, such as a water supply system, a closed water tank, or steam tracer lines, thereby respectively bleeding or draining water therefrom or admitting steam to the tracer lines and thereby preventing damage to the system and subsequent water damage during a thaw.
It has also been discovered that the freezing of water can be utilized to provide an internal sealing means that requires no additional sealing device, such as an o-ring.
It has additionally been found that the freezing of water can be utilized to bleed water lines and to operate steam tracer lines for protection of aqueous systems during freezing weather but not during thaws