Described is a priming device to prime a gas from a fluid delivery system by receiving the gas and a fluid used to push the gas into a chamber, the priming device including a cover body having a lid, and a housing having a chamber, an inlet port and an opening to release gas received into the chamber. The device has a priming-ready configuration where the medical connector and the housing are coupled with the cover body, and the fluid path of the medical connector and the passage of the housing remain sealed, a priming configuration where the medical connector is advanced in the cover body to fluidly couple with the housing, and a post-priming configuration where the housing is decoupled from the cover body and the lid closed to prevent contamination of the medical connector.