A method for manufacturing a safety catheter includes a flexible, multi-lumen shaft having a drain lumen draining fluid adjacent a distal tip of the shaft out a proximal drain end of the shaft and an inflation lumen. A hollow balloon portion has an inflation port fluidically connecting the inflation lumen to the balloon interior to inflate the balloon outwardly larger than a diameter of the shaft. The drain lumen is fluidically connected to the balloon interior by a drainage port. A hollow stretch valve in the drain lumen prevents fluid from passing through the drainage port in a steady state and permits fluid to pass therethrough in a stretched state when the shaft is stretched. Distal of a proximal end of the stretch valve, the shaft has a stretching extent that is relatively more stretchable than at least a portion of the shaft that is proximal of the stretching extent.