A sampling port (10) has a generally tubular body (12) defined by a wall (18) arranged about an axis (42) which defines a space (21) for a sampling vial (72, 102). The wall (18) has a waisted region (60) intermediate a base (16) and an open end (20). The wall (18) is expandable radially in at least the waisted region (60) to accommodate different sized sampling vails (72, 102).
