Ring insert for combustor liner and associated method

A gas turbine combustor liner (10) has at least one circumferential row of air holes (16) which are arranged to supply air in a radial direction into a combustion chamber at the inside of the wall inside. One or more of the air holes have a fixed in the respective hole ring (22), wherein the ring has a substantially circular body and a pair of lips (26, 28) which are diametrically opposite from an inner end of the ring into a extend upstream and downstream direction.