63mm MDPE inserts, are they needed?

[Samej1987]

I have to join two pieces of 63mm MDPE, the coupler came with plastic inserts. I always thought they were to help avoid crushing the pipe.

The MDPE pipe is so thick i wouldnt think i could crush it if i tried, therefore why is it supplied?

The pipe is having pumped grey water through it and i dont like the idea of constricting it at any point. (i also dont want to do it wrong and it leaks, hence the question.)

 

[Ian H]

I always use them but don't see the point, once the pipe is under pressure it will be pressing itself outwards.

I have a mate who works for AMEY fitting water meters, no one there uses inserts on 25mm mpde and your 63mm will be much stronger.