A catheter assembly is disclosed having a catheter adapter and a needle hub. The catheter adapter has an inner lumen with a septum located within the inner lumen. An introducer needle is inserted through the inner lumen. A septum activator also located within the inner lumen, such that a distal end of the septum activator contacts the septum. The septum activator has an internal cavity and a cavity seal forming a surface of the internal cavity.
