Weldon 10161 1 Quart 721 PVC Cement, BlueWeldon 10161 1 Quart 721 PVC Cement, Blue, Features; PVC cement; Premium, high strength formulation for irrigation, DWV, pool & spa and plumbing; May be used without primer on schedule 40 and SDR water piping systems thru 4" unless primer is required by local code; Do not use 721⢠without primer in any other application schedule or size such as schedule 80 industrial applications; When primer is used, joints must be properly cured before backfilling; Maximum 6" PVC pipe or 4" schedule 80 PVC; Fast drying; Blue; 1 quart