A manifold (46) for connection to a medical/surgical waste collection unit is described, wherein the waste collection unit has a receiver for receiving the manifold. Said manifold comprises a housing having a void space, wherein the housing is dimensioned to fit in the waste collection unit receiver. The manifold further comprises at least one fitting (48) attached to the housing that extends away from the housing. The fitting is dimensioned to receive a suction line. At least one port (237) formed in the manifold provides a fluid communication opening between each fitting and the interior void space of the manifold. A valve unit (248) is associated with the fitting. The valve unit is configured to allow fluid flow through the fitting into the housing void space and block fluid flow from the housing void space out through the fitting. An outlet opening (170) is provided in the manifold housing that allows fluid from said void space into the waste collection unit. The valve unit is disposed in the housing void space and includes a hub (250) formed from compressible material. Said hub has opposed first and second faces, wherein the hub first face is distally directed and disposed against the housing. Said hub is held in the housing in that it is compressed between components of the manifold and has a number of ribs that extend outwardly from each of the opposed faces of the hub. At least one valve member (262) is pivotally connected to and extends from said hub. Said valve member is positioned and dimensioned to cover the port.