1) Plastic-Commingling. There shall be no commingling of plastic materials within the same plumbing system except through the use of proper adaptors or approved solvent as listed in Appendix A.Table A, for connections transitioning from one material to another, only.
Transition glue is rated for non-pressurized systems only, however our gas utility uses it to connect new PVC lines to the old "high pressure" ABS gas lines.