VPC Home-Flex 18-445-005 1/2" IPS Poly DR 9.3 to 1/2" MIP Underground Yellow Poly Gas Transition. The IPS size Yellow Poly Gas Pipe Transition Fitting allows you to transition from MDPE Yellow Poly Gas Pipe to metal pipe. One end of this Transition Fitting is plain in. IPS poly gas pipe that will connect to your run of poly pipe using one of the Home-Flex Underground fittings such as the Coupler, Tee or Elbow. The other end of this Transition Fitting has steel Male Pipe Threads that you can use to couple to metal gas pipe. Be sure to use an appropriate thread sealant on the pipe threads.