push-fit plastic water pipe. How vital are the inswerts?

[AL_z]

When using push-fit couplers in pipe, how necessary is it to use inserts to support the pipe where it fits in the coupler? I seem to recell forgetting to use them once or twice but have never noticed a leak develop. Does anyone here purposely avoid using inserts in the belief thay are unnecessary?

Thanks

Al

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "AL_z" saying something like:

I've always used them, simply because the makers say it is necessary and a flood is just so inconvenient. To deliberately not use them would be pretty daft.

[Andrew Gabriel]

Certainly essential for compression fittings on plastic - I had to fix a leak on a new run a friend installed, and it was on the one and only join where he'd forgotten to use an insert (and it was a low pressure supply).

[1501]

And the one and only one that leaks will be the least accessible one.

Also known as "The law of sod".

[Owain]

Probably Dribble.

Owain

[dom]

I've missed them out on *temporary* work, when I ran out. No leaks seal on speedfit at 3 bar (cold supply only).

As others have said, disasterous on compression fittings.

[The Natural Philosopher]

Low pressure is probably the worst, as it wont swell the pipe..

[Tim Watts]

I've done the same - forgotton and observed no leaks. However, I have gone back and put the inserts in.

Do it - you know it makes sense...