Schedule 40 PVC fittings are the standard for use in irrigation systems, both for Drip Irrigation and Sprinkler Irrigation.
When installing a few simple rules apply.
If gluing make sure both parts are clean then coat both parts with a thin layer of PVC glue.
If pipe is old or has been exposed to weather use a PVC cleaner first.
If both fittings are threaded use two to three wraps of teflon tape on the male threads before screwing together.
If threading a softer plastic piece to threaded PVC teflon tape is not normally needed but one or two wraps maximum may be used. Most softer plastic in this situation will be a black color.
Grey sprinkler risers should always be installed with teflon tape.