A method facilitates replacing a portion of a gas turbine engine combustor liner. In accordance with one embodiment an Offline Access Server offline Web infrastructure based on a scalable, polite communication technology. Thereby are obtained ceramic discs for utilization in mixer valves of single-lever mixer type whose friction coefficient is lower that of the ceramic discs currently used, all this without loss of leak tightness, without having to use grease and with a low manufacturing cost.