A slit valve 10 for use with an inflatable medical device having a flange surface 12 with an opening therein. The slit valve 10 has a valve body 14 connected to the flange surface 12 and a chamber formed in the valve body 14 for accepting an inflation tube 34 inserted through the opening in the flange surface 12. The slit valve 10 has a concave section at one or both ends, which are connected by a slit 24 formed in the valve body 14.
