A fluid drainage system adapted for sealed engagement to a first end of a drainage tube having the opposite end positioned at a fluid drainage site in a patient, comprising: a first container made of polymeric material, said first container having an interior cavity defined by a sidewall in sealed engagement with an upper end and a lower end; said first container having a useable configuration wherein negative air pressure is present within said interior cavity; a connector extending from said upper end and having an axial conduit therethrough communicating between said interior cavity and an axial passage of an engaged tube configured at a first end for sealed engagement to said connector; a second end of said tube, configured for a sealed engagement of said axial passage, with said first end of said drainage tube; a sealing component having a first position blocking communication of a suction caused by said negative pressure in said interior cavity, through said axial passage to said second end of said tube, and having a second position, allowing communication of said suction to said axial passage; and whereby said fluid drainage system is engageable to said drainage tube with said sealing component in said first position, is engageable without loss of negative pressure in said interior cavity, and can communicate said suction to draw fluid from said patient to said interior cavity with said sealing component in said second position, characterised by the sidewall of said first container being arched from the lower end toward the upper end, and a continuous annular arched portion extending outwardly or inwardly, respectively from said sidewall around a circumference of said first container in a central area thereof between said upper end and said lower end; said annular curved portion defining a structural reinforcement to said sidewall to increase a resistance to inward deflection from a force from said negative pressure in said internal cavity. a first container made of polymeric material, said first container having an interior cavity defined by a sidewall in sealed engagement with an upper end and a lower end; said first container having a useable configuration wherein negative air pressure is present within said interior cavity; a connector extending from said upper end and having an axial conduit therethrough communicating between said interior cavity and an axial passage of an engaged tube configured at a first end for sealed engagement to said connector; a second end of said tube, configured for a sealed engagement of said axial passage, with said first end of said drainage tube; a sealing component having a first position blocking communication of a suction caused by said negative pressure in said interior cavity, through said axial passage to said second end of said tube, and having a second position, allowing communication of said suction to said axial passage; and whereby said fluid drainage system is engageable to said drainage tube with said sealing component in said first position, is engageable without loss of negative pressure in said interior cavity, and can communicate said suction to draw fluid from said patient to said interior cavity with said sealing component in said second position, characterised by the sidewall of said first container being arched from the lower end toward the upper end, and a continuous annular arched portion extending outwardly or inwardly, respectively from said sidewall around a circumference of said first container in a central area thereof between said upper end and said lower end; said annular curved portion defining a structural reinforcement to said sidewall to increase a resistance to inward deflection from a force from said negative pressure in said internal cavity.