Body liquids drainage control method and apparatus.

摘要

A drainage control valve (10) is provided having a housing (11) inlet tube (16) and outlet tube (33). A piston (22) includes a flexible valve seal (23) to close an inlet opening (26) under the action of return spring (25). At a predetermined inlet pressure the piston moves against the return spring to open communication between the inlet tube and outlet tube. The suction of fluid draining through the housing acts on the rear face of the piston to maintain the valve in the open condition until drainage is substantially complete.