Typically, o-ring fittings are used for larger diameter pipes (4 inch and larger) where the runs consist of longer distances with a low density of fittings. Examples would be outside of the building civil work and inside (below grade) storm drainage.
When you have smaller diameter pipes and a high density of fittings, such as a bathroom group, glue fittings would be used.
Some advantages of o-ring fittings are:
- fittings can be reused
- quicker to install for large diameter pipes (> 6")
- no time constraint for adjustment of fittings
Some advantages of glue fittings are:
- fittings stay in the place they were set to
- available for small diameter pipes
- quicker to install when there is a high density of fittings