On 25/04/2013 12:39, Gazz wrote:

Firstly, a 2 litre pop bottle is pretty flimsy, whilst it will handle
the couple of bar pressure in a motorhomes water system, can it handle
the vibrations and movement from driving down the road... basically if
it fails, you will pump the contents of the water tank into the living
area,

2 litre PET bottles are really remarkably robust. Scratch them and
you'll be in trouble but as long as the hose connector isn't rigidly
fixed to the van so it can vibrate with the bottle it'll probably
survive quite a lot. The lid will probably fail before the bottle.

Last one i bought for the cold side of the water system in my motorhome
was fiamma branded, and cost me about £14, looked similar to the one you
showed, but blue,

OTOH for 14 quid I might well go with the proper solution :-)