# US 2014/0150892 A1 · Access cover in backflow prevention device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0150892 A1 - Document ID: US20140150892A1 - Status: Published application - Kind: A1 - Application number: 13/705,024 - Filed: 2012-12-04 - Published: 2014-06-05 - Earliest claimed: 2012-12-04 - Inventors: Douglas Hunter Powell - Web page: https://patentgrep.com/patent/US20140150892A1 ## CPC - E03F 7/04: Valves for preventing return flow {(in gullies, drains or the like E03F5/042)} - F16K 27/0209: {Check valves or pivoted valves} - F16K 27/12: Covers for housings - Y10T 137/3294: Valved - Y10T 137/7838: Plural - Y10T 137/7898: Pivoted valves - Y10T 137/87917: Flow path with serial valves and/or closures - E03F: SEWERS; CESSPOOLS - F16K: VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING {(devices for emptying and evacuating the excess liquid in valves or conduits F16L55/07)} - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A backflow prevention device including an opening in the housing configured to provide a user with access to the upstream check valve and the downstream check valve. The backflow prevention device further includes a cover configured to cover the entirety of the opening. The cover includes a portion of a lateral surface of a right cylinder. The backflow prevention device additionally includes a seal configured to sealingly engage the cover and the housing along the perimeter of the cover. ## Claims ### Claim 1 A backflow prevention device, the backflow prevention device comprising: a housing defining a water flow stream; an upstream shutoff valve, wherein the upstream shutoff valve is configured to allow a user to control the water flow stream through the housing; an upstream check valve: located within the housing downstream of the upstream shutoff valve; and including: an orifice, wherein the orifice is configured to allow the water flow stream through the upstream check valve; and a clapper, wherein the clapper is configured to: allow the water flow stream through the orifice when open; and prevent the water flow stream through the orifice when in a closed position by mating with the orifice; a downstream check valve: located within the housing downstream of the upstream check valve; and including: an orifice, wherein the orifice is configured to allow the water flow stream through the downstream check valve; a clapper, wherein the clapper is configured to: allow the water flow stream through the orifice when open; and prevent the water flow stream through the orifice when in a closed position by mating with the orifice; a downstream shutoff valve, wherein the downstream shutoff valve is configured to allow a user to control the water flow stream through the housing; an access port in the housing configured to provide a user with access to the upstream check valve and the downstream check valve; a cover: configured to cover the entirety of the access port; and including a portion of a lateral surface of a right cylinder; and wherein the lateral surface is non-concentric with the axis of curvature of the housing at the access port; and a seal configured to sealingly engage the cover and the housing along the perimeter of the cover. ### Claim 2 (depends on 1) The backflow prevention device of claim 1 further comprising: a first elastomer disk in the clapper of the upstream check valve, the first elastomer disk sealing the mating of the clapper with the orifice; and a second elastomer disk in the clapper of the downstream check valve, the second elastomer disk sealing the mating of the clapper with the orifice. ### Claim 3 (depends on 2) The backflow prevention device of claim 2 further comprising: a first lip located on the outer edge of the orifice of the upstream check valve configured to sealingly engage the first elastomer disk; and a second lip located on the outer edge of the orifice of the downstream check valve configured to sealingly engage the second elastomer disk. ### Claim 4 (depends on 1) The backflow prevention device of claim 1 further comprising a relief valve, wherein the relief valve is configured to operate based upon the pressure differential between: the volume between the upstream shutoff valve and the upstream check valve; and the volume between the upstream check valve and the downstream check valve. ### Claim 5 (depends on 1) The backflow prevention device of claim 1 further comprising: a first bias configured to hold the clapper of the upstream check valve in the closed position unless a predetermined upstream pressure exists; and a second bias configured to hold the clapper of the downstream check valve in the closed position unless a predetermined downstream pressure exists. ### Claim 6 (depends on 1) The backflow prevention device of claim 1, wherein: the first bias includes a first spring; and the second bias includes a second spring. ### Claim 7 (depends on 1) The backflow prevention device of claim 1 further comprising a check retainer configured to maintain a minimum distance between the upstream check valve and the downstream check valve. ### Claim 8 (depends on 1) The backflow prevention device of claim 1 further comprising: an upstream control configured to allow a user to control the position of the upstream shutoff valve; and a downstream control configured to allow a user to control the position of the downstream shutoff valve. ### Claim 9 (depends on 1) The backflow prevention device of claim 1 further comprising: an upstream sensor configured to trigger an alarm when the upstream shutoff valve is in a closed position; and a downstream sensor configured to trigger an alarm when the downstream shutoff valve is in a closed position. ### Claim 10 (depends on 1) The backflow prevention device of claim 1 further comprising: a first sensing port configured to provide access through the housing to the volume upstream of the upstream shutoff valve; a second sensing port configured to provide access through the housing to the volume between the upstream shutoff valve and the upstream check valve; a third sensing port configured to provide access through the housing to the volume between the upstream check valve and the downstream check valve; and a fourth sensing port configured to provide access through the housing to the volume between the downstream check valve and the downstream shutoff valve. ### Claim 11 (depends on 1) The backflow prevention device of claim 1, wherein the radius of curvature of the cover is larger than a radius of curvature of the housing at the access port. ### Claim 12 A backflow prevention device, the backflow prevention device comprising: a housing defining a water flow stream; an upstream shutoff valve, wherein the upstream shutoff valve is configured to allow a user to control the water flow stream through the housing; an upstream check valve: located within the housing downstream of the upstream shutoff valve; and including: an orifice, wherein the orifice is configured to allow the water flow stream through the upstream check valve; and a clapper, wherein the clapper is configured to: allow the water flow stream through the orifice when open; and prevent the water flow stream through the orifice when in a closed position by mating with the orifice; a downstream check valve: located within the housing downstream of the upstream check valve; and including: an orifice, wherein the orifice is configured to allow the water flow stream through the downstream check valve; a clapper, wherein the clapper is configured to: allow the water flow stream through the orifice when open; and prevent the water flow stream through the orifice when in a closed position by mating with the orifice; and a downstream shutoff valve, wherein the downstream shutoff valve is configured to allow a user to control the water flow stream through the housing; an access port in the housing configured to provide a user with access to the upstream check valve and the downstream check valve; a cover: configured to cover the entirety of the access port; and including a portion of a lateral surface of a right cylinder; and wherein the lateral surface is non-concentric with the axis of curvature of the housing at the access port; wherein the radius of curvature of the cover is larger than a radius of curvature of the housing at the access port; and a seal configured to sealingly engage the cover and the housing along the perimeter of the cover. ### Claim 13 (depends on 12) The backflow prevention device of claim 12 further comprising a mount configured to secure the cover to the housing. ### Claim 14 (depends on 12) The backflow prevention device of claim 12, wherein the mount includes: a first attachment point to the housing; and a second attachment point to the housing antipodal to the first attachment point. ### Claim 15 (depends on 12) The backflow prevention device of claim 12 further comprising: an attachment configured to secure the cover to the housing. ### Claim 16 (depends on 12) The backflow prevention device of claim 12, wherein the attachment includes a bolt. ### Claim 17 A backflow prevention device, the backflow prevention device comprising: a housing defining a water flow stream; an upstream shutoff valve, wherein the upstream shutoff valve is configured to allow a user to control the water flow stream through the housing; an upstream check valve: located within the housing downstream of the upstream shutoff valve; and including: a seat configured to mate with a portion of the housing; an orifice, wherein the orifice is configured to allow the water flow stream through the upstream check valve; and a clapper, wherein the clapper is configured to: allow the water flow stream through the orifice when open; and prevent the water flow stream through the orifice when in a closed position by mating with the orifice; a downstream check valve: located within the housing downstream of the upstream check valve; and including: a seat configured to mate with a portion of the housing; an orifice, wherein the orifice is configured to allow the water flow stream through the downstream check valve; a clapper, wherein the clapper is configured to: allow the water flow stream through the orifice when open; and prevent the water flow stream through the orifice when in a closed position by mating with the orifice; and a downstream shutoff valve, wherein the downstream shutoff valve is configured to allow a user to control the water flow stream through the housing; and an access port in the housing configured to provide a user with access to the upstream check valve and the downstream check valve; a cover: configured to cover the entirety of the access port; and including a portion of a lateral surface of a right cylinder; and wherein the lateral surface is non-concentric with the axis of curvature of the housing at the access port; wherein the radius of curvature of the cover is larger than a radius of curvature of the housing at the access port; a seal configured to sealingly engage the cover and the housing along the perimeter of the cover; and a mount configured to secure the cover to the housing. ### Claim 18 (depends on 17) The backflow prevention device of claim 17, wherein the seal includes an elastomer. ### Claim 19 (depends on 17) The backflow prevention device of claim 17, wherein: the housing is cylindrical; and the access port is half-cylindrical. ### Claim 20 (depends on 17) The backflow prevention device of claim 17, wherein the cover is secured to the mount along the edges of the cover.