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US 6,196,246 B1Granted
Freeze-resistant plumbing system in combination with a backflow preventer
OwnerWilliam D. Folsominventor
Life of this patent
Estimating the term…
Abstract
A plumbing system which, when ambient outdoor temperatures drop below freezing, circulates water to prevent it from freezing, utilizing a check valve to prevent water from flowing back into the water main and further utilizing a relief valve which can open to the atmosphere and relieve pressure in the system if necessary. The system can have two separate circulation pumps, one for hot water and one for cold water.
Claims7
A freeze-resistant plumbing system comprising:
- a service pipe for supplying water from a water main pipe to at least one water fixture in a structure;
- a housing with at least one check valve installed between said service pipe and said water main pipe;
- a first circulation pump connected in line with said service pipe, the circulation pump having an outlet and an inlet;
- a closed cold water system loop disposed between the outlet and the inlet of the first circulation pump;
- an ambient temperature-sensing means which activates said first circulation pump upon sensing an ambient temperature below a predetermined value, causing water untapped by the fixture to circulate continuously through the closed cold water system loop from the outlet to the inlet of the circulation pump at a desired rate to prevent freezing of said water, further causing said check valve to close when circulating water pressure exceeds water pressure in the service pipe, thereby preventing water from flowing back through the service pipe to the water main pipe;
- a relief valve assembly in said housing downstream of said check valve disposed in a reverse flow direction, said relief valve assembly having dimensions sufficiently large enough to empty said service pipe and further having a port open to outside atmosphere and a relief valve operable to open position automatically in response to a high pressure condition in said service pipe which exceeds a predetermined value, which causes said relief valve to open, thereby discharging water under high pressure to the outside atmosphere through said port.
3 more elements
A method for preventing a service pipe from freezing comprising the following steps:
- installing a relief valve assembly downstream from at least one check valve in a housing for passage of water between a water main pipe and a service pipe;
- installing a relief valve in said relief valve assembly, said relief valve being moveable between a closed and an open position;
- providing means for controlling said relief valve so that said relief valve automatically opens in response to a high pressure condition in said service pipe which exceeds a predetermined value;
- providing a port in said relief valve assembly, said port being open to the atmosphere so that said high pressure condition can be relieved;
- installing a first circulation pump in line with said service pipe, the first circulation pump having an outlet and an inlet;
- providing a closed cold water system loop disposed between the outlet and the inlet of the first circulation pump;
- providing ambient temperature means which activates said first circulation pump upon sensing an ambient temperature below a predetermined value, said circulation pump thereupon causing water untapped by the fixture to circulate continuously through the closed cold water system loop from the outlet to the inlet of the first circulation pump at a desired rate to prevent freezing of said water, further causing said check valve to dose when circulating water pressure exceeds water pressure in the service pipe, thereby preventing untapped water from flowing back through the service pipe to the water main pipe.
4 more elements
Dependencies are inferred from the claim text.