Check valve for use with intravenous pump
First Claim
1. A check valve for incorporation into a liquid supply system for preventing flow from a location in the system downstream from the check valve to a location upstream from the check valve when the downstream pressure is greater than the upstream pressure by no more than a selected value, the check valve comprising:
- a housing configured to be disposed in the system between an upstream liquid source and a downstream portion of the system;
a valve seat disposed in the housing;
a valve member disposed in the housing having an upstream-facing surface and a downstream-facing surface; and
means in the housing for supporting the valve member downstream from the valve seat when the upstream pressure is greater than the downstream pressure, the valve member being movable to the valve seat for preventing flow in an upstream direction through the check valve when the downstream pressure is greater than the upstream pressure by no more than a selected value, the valve member including means for relieving downstream pressure when the downstream pressure exceeds the upstream pressure by the selected value.
5 Assignments
0 Petitions
Accused Products
Abstract
A medical liquid administration set is provided with a check valve which is configured to relieve excess pressure downstream from the check valve. The check valve includes a resilient valve disc and a valve seat, which engages the disc when the valve is closed. The administration set includes primary and secondary liquid sources connected through a Y-connector to a pump, which pumps liquids sequentially from the first and second sources to a patient. The check valve is disposed in the set between the Y-connector and the primary liquid source and is in its closed position with the valve disc on the valve seat when the liquid level in the secondary liquid source is higher than the liquid level in the primary source to thereby prevent backflow of liquid from the secondary source into the primary. The check valve is in its open position, allowing flow from the primary source to the patient when the liquid level in the secondary source has fallen to the level of liquid in the primary source. The valve disc is of a resilient material, and a slit is through the disc so that when the downstream pressure is greater than the upstream pressure by a selected value, the slit is forced open to relieve the excessive pressure.
136 Citations
18 Claims
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1. A check valve for incorporation into a liquid supply system for preventing flow from a location in the system downstream from the check valve to a location upstream from the check valve when the downstream pressure is greater than the upstream pressure by no more than a selected value, the check valve comprising:
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a housing configured to be disposed in the system between an upstream liquid source and a downstream portion of the system; a valve seat disposed in the housing; a valve member disposed in the housing having an upstream-facing surface and a downstream-facing surface; and means in the housing for supporting the valve member downstream from the valve seat when the upstream pressure is greater than the downstream pressure, the valve member being movable to the valve seat for preventing flow in an upstream direction through the check valve when the downstream pressure is greater than the upstream pressure by no more than a selected value, the valve member including means for relieving downstream pressure when the downstream pressure exceeds the upstream pressure by the selected value. - View Dependent Claims (2, 3, 4, 5, 6)
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- 7. In a check valve for preventing liquid flow from downstream thereof to upstream thereof when the downstream pressure is greater than the upstream pressure by no more than a selected value, the check valve comprising a flexible valve disc, a housing comprising a lower housing member connected to an upper housing member, wherein the lower housing member includes means for supporting the valve disc when the valve is open, to thereby permit liquid flow from upstream thereof to downstream thereof and wherein the upper housing member includes a valve seat for engaging the valve disc when the valve is closed, the improvement comprising means formed in the valve disc for relieving downstream pressure when the downstream pressure exceeds the upstream pressure by the selected value.
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13. A medical liquid administration set for administering first and second liquids to a patient comprising:
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a first liquid source; a second liquid source; connector means for combining two flows into one flow; first conduit means for connecting the first liquid source to the connector means; second conduit means for connecting the second liquid source to the connector means; third conduit means for connecting the one flow from the connector means to the patient; means disposed along a path of the third conduit means for pumping liquids from the first and second liquid sources to the patient; and a check valve disposed along a path of the first conduit means for preventing liquid flow from downstream of the check valve to upstream thereof when the downstream pressure is greater than the upstream pressure by no more than a selected value, the check valve comprising a housing, a valve seat disposed in the housing, a valve member disposed in the housing having an upstream-facing surface and a downstream-facing surface, means in the housing for supporting the valve member downstream from the valve seat when the upstream pressure is greater than the downstream pressure, the valve member being movable to the valve seat for preventing flow in an upstream direction through the check valve when the downstream pressure is greater than the upstream pressure by no more than a selected value, the valve member including means for relieving downstream pressure when the downstream pressure exceeds the upstream pressure by the selected value. - View Dependent Claims (14, 15, 16, 17, 18)
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Specification