Abstract: A sealing engagement between components in a catheter system is made using an elastomeric material. The sealing engagement is formed in a manner that allows a catheter needle to pass through a passageway in the center of the elastomeric material maintaining the sealing engagement between the components of the catheter system. The elastomeric material is shaped to fit circumferentially into one of the components and shaped to mechanically assist the passageway to close up after a needle passes through the passageway during retraction. The elastomeric material remains in a stationary position as the needle is retracted. One or more structures can be integrated within the elastomeric material to provide for compression and to prevent deformation of the passageway.