A dressing assembly for providing negative-pressure therapy to a tissue site, the dressing assembly comprising: a pouch (105, 205, 305, 405); a cover (103, 203, 303, 403) configured to cover the pouch (105, 205, 305, 405); a negative-pressure source (104, 204, 304, 404) having resilient walls fluidly coupled to the pouch (105, 205, 305, 405), the negative-pressure source (104, 204, 304, 404) having a first position and a second position; a first check valve (144, 244, 344, 444) fluidly coupled to the pouch (105, 205, 305, 405) and the negative-pressure source (104, 204, 304, 404) and operable to prevent fluid flow from the negative-pressure source (104, 204, 304, 404) into the pouch (105, 205, 305, 405) if the negative-pressure source (104, 204, 304, 404) is moved from the second position to the first position; and a second check valve (150, 250, 350, 450) fluidly coupled to the negative-pressure source (104, 204, 304, 404) and the ambient environment and configured to prevent fluid flow from an ambient environment into the negative-pressure source (104, 204, 304, 404) if the negative-pressure source (104, 204, 304, 404) is moved from the first position to the second position, characterized in that the pouch (105, 205, 305, 405) is coupled to the cover (103, 203, 303, 403), the cover (103, 203, 303, 403) having a periphery extending beyond an edge of the pouch (105, 205, 305, 405); the negative-pressure source (104, 204, 304, 404) is coupled to the cover (103, 203, 303, 403); and the dressing assembly further comprises a tube fluidly coupling the pouch (105, 205, 305, 405) to the negative-pressure source (104, 204, 304, 404) through the cover (103, 203, 303, 403), wherein the first check valve (144, 244, 344, 444) is disposed in the tube (140, 240, 340, 44). a pouch (105, 205, 305, 405); a cover (103, 203, 303, 403) configured to cover the pouch (105, 205, 305, 405); a negative-pressure source (104, 204, 304, 404) having resilient walls fluidly coupled to the pouch (105, 205, 305, 405), the negative-pressure source (104, 204, 304, 404) having a first position and a second position; a first check valve (144, 244, 344, 444) fluidly coupled to the pouch (105, 205, 305, 405) and the negative-pressure source (104, 204, 304, 404) and operable to prevent fluid flow from the negative-pressure source (104, 204, 304, 404) into the pouch (105, 205, 305, 405) if the negative-pressure source (104, 204, 304, 404) is moved from the second position to the first position; and a second check valve (150, 250, 350, 450) fluidly coupled to the negative-pressure source (104, 204, 304, 404) and the ambient environment and configured to prevent fluid flow from an ambient environment into the negative-pressure source (104, 204, 304, 404) if the negative-pressure source (104, 204, 304, 404) is moved from the first position to the second position, characterized in that the pouch (105, 205, 305, 405) is coupled to the cover (103, 203, 303, 403), the cover (103, 203, 303, 403) having a periphery extending beyond an edge of the pouch (105, 205, 305, 405); the negative-pressure source (104, 204, 304, 404) is coupled to the cover (103, 203, 303, 403); and the dressing assembly further comprises a tube fluidly coupling the pouch (105, 205, 305, 405) to the negative-pressure source (104, 204, 304, 404) through the cover (103, 203, 303, 403), wherein the first check valve (144, 244, 344, 444) is disposed in the tube (140, 240, 340, 44).