A medical valve assembly includes a tube extending between a first tube endanda second tube end to define a passageway extending along a longitudinal axisbetween the ends.A plunger plate extends radially from the second tube end of the tube, and avalve housingsurrounds the tube about the second tube end and extends from a first valvehousing end to asecond valve housing end. The valve housing includes a flange extendingradially inwardlyfrom the second valve housing end and disposed in spaced relationship with theplunger plate todefine a distance dimension D extending therebetween. An elastomeric seal iscompressedbetween the plunger plate and the flange, and one of the valve housing and thetube is axiallymovable relative to the other to vary the distance between said plunger plateand said flange andadjust an inner diameter of the elastomeric seal.
