Barbed pipe fittings should only be used with LDPE Pipe ( Low density polyethylene pipe). Low density polyethylene pipe can be used on the surface or just below the surface. The pipe is 4 bar rated and the fittings are 6 bar rated.
Installation tips
The LDPE pipe will need to be warm prior to the installation of a barbed fitting. This will make sure that the fitting is easy to push in and will allow the pipe to shrink back on to the barbs making a tough durable and reliable fitting