A fluid delivery system adapted to isolate an ampoule and/or process line during purge, including an inlet control valve connecting a source of pressurized gas to a refillable ampoule, an outlet control valve connecting the refillable ampoule to a location of use, a process control valve connecting a process line to the refillable ampoule, a process isolation valve, and a purge supply valve, e.g., a three-way purge supply valve, arranged between the process isolation valve and the process control valve. A method of purging a fluid delivery system is also disclosed, including closing a process isolation valve, connecting a process line to a refillable ampoule, supplying a purge gas through a purge supply valve, e.g., a three-way purge supply valve, and cycling open and close at least once a process control valve coupled to the process line. A manifold for use in refilling an ampoule and purging a fluid supply system is also described.