A system for inflating a cryogenic ablation catheter balloon, the system comprising a fluid source containing a fluid in a liquid state, a first supply line fluidly coupled to the fluid source and configured to be fluidly coupled to an internal space within the cryogenic ablation catheter balloon, the first supply line including an inline multi-stage pressure regulating system. The multi-stage pressure regulating system includes a first stage configured to cause the fluid to transition from the liquid state to a gas state, and a second stage downstream of the first stage configured to maintain the fluid downstream of the second stage at a pressure corresponding to an inflation pressure of cryogenic ablation catheter balloon.
