Hi Chaps,
Wayne,
All I have done is pushed the 10mm pipe into the cut off BP black pipe and put a jubilee clip on......no insert....and I have never had any trouble with it

Bazz,
Yes I wear it on my back ALL the time. I have NO other system. The trick is to mount the BP so as you DO NOT lift it with your arms.
Now I have gone 100% Backpack

and have developed my system around it.
I have a 1/2 ton trailer with a 250ltr flat tank a 50ltr/min transfer pump and the BP is mounted at back hieght on the back of the trailer so all I do is store the BP full back up to it strap on, grab a pole, connect up, turn on BP, extend pole, flip the flow valve on the pole and wash away. When the BP runs out of water all I do is back to the trailer back up to the rack, BP off, lid off, pipe in top, flip transfer pump switch, 30 secs - full, flip tran pump switch, lid on, back up, strap on.....etc.
I have learned where to fill up and to work furthest away first etc. Its just me, BP and pole. I can get just about anywhere.