Rated 4 out of 5Â by MisterE Tight fit, do the job.
I'm not entirely convinced that these are necessary for the 22mm MDPE pipe, but if you are burying it underground you don't really want to take a chance in a leaky coupling. A tight fit, they have to be pounded in with a soft mallet.
Rated 5 out of 5Â by brennyn Inserts
Very well made just insert them into the pipe and away you go (must be used with mdpe pipe to stop the chance of the pipe collapsing