Have encountered a big surprise. Yellow gas pipe (1 1/4") supplying natural gas to a pool heater and an inside gas log fireplace ... with WHITE PVC for the 90 degree El's and unions glued with blue glue. Are you a master plumber from the 1980's? I understand this was done before the invention of HDPE yellow pipe with fusion fittings and stab connectors. This old pipe may have been lined with PVC which would not allow gas to leak through the lining. I am told the old pipe, fittings and glue are hard to source. Know anyone who has it? I need to transition from the old pipe to the new HDPE ... OR, abandon the old line entirely and re-pipe back to the main with modern yellow gas pipe. Your thoughts??