Automatic draining back flow prevention device
AssigneeWCM Industries, Inc.
InventorsWilliam T. Ball, Eric Pilarczyk
Life of this patent
Estimating the term…
Abstract
A double check valve is provided that includes an in-line inlet check valve and an outlet check valve that cooperate to prevent back flow of fluid through the valve. The check valve also includes at least one vent that allows for fluid trapped within the check valve to drain, thereby preventing freezing of the check valve and hydrant to which it is interconnected. The check valve provided omits many superfluous components and thus is smaller and easier to install than check valves of the prior art.
Claims20
A method of manufacturing a back flow prevention device:
- providing a valve body that defines an inlet volume and an outlet volume;
- forming at least one vent in the valve body that allows fluid from inside the valve body to escape;
- positioning a seal within the valve body such that the seal selectively blocks the at least one vent;
- securing the seal within the valve body with a valve cap;
- positioning an inlet check valve within the inlet volume, wherein an inlet check body of the inlet check valve is biased at least partially within the inlet volume;
- and
- positioning an outlet check valve within the outlet volume, wherein an outlet check body of the outlet check valve is biased at least partially within the outlet volume, wherein at least a portion of the outlet check body is coupled to the inlet check body.
A method of preventing back flow into a fluid source:
- attaching a back flow prevention device to a faucet that selectively controls a fluid flow from the fluid source, wherein the back flow prevention device includes a valve body with an inlet, an outlet, and at least one vent, a seal proximate the at least one vent, and a valve assembly having an inlet check valve and an outlet check valve;
- and
- selectively moving the valve assembly to define a plurality of flow conditions of the back flow prevention device, wherein:
- a back siphonage condition of the plurality of flow conditions is defined with a hose connected to the outlet of the valve body and a vacuum at the fluid source such that the outlet check valve moves towards a closed position and back flow through the valve body is prevented from entering the fluid source;
- and
- an open flow condition of the plurality of flow conditions is defined with the hose not connected to the outlet of the valve body and the fluid flow is supplied to the inlet such that the fluid flow forces the seal to directly block the at least one vent and moves the valve assembly towards an open position so that the fluid flow is channeled through the valve body and out the outlet.
A method of testing a double check valve that includes an inlet check valve and an outlet check valve, the method comprising:
- coupling a hose to a valve body, wherein the valve body includes an inlet and an outlet, wherein one or more vents are defined in the valve body between the inlet and the outlet, and wherein the hose couples to the outlet;
- substantially simultaneously with coupling the hose to the valve body, moving a plunger into the valve body, wherein the plunger forces the outlet check valve towards engagement with a seat within the valve body;
- adding fluid into the outlet of the valve body;
- and
- determining integrity of the engagement between the outlet check valve and the seat.
Dependencies are inferred from the claim text.