"Gazz" wrote:
"Tim+" wrote in message
...
wrote:
On Thursday, April 25, 2013 10:19:43 AM UTC+1, Tim+ wrote:
I'd like to experiment with using a 2L coke bottle as a pressure
vessel but I haven't worked out how best to make a leakproof plumbed
connection to the bottle.


http://www.mindsetsonline.co.uk/prod...roducts_id=354

Nice, but I think the connections would be just too small. I want it to
act as a pressure reservoir to prevent rapid pump cycling in a
motorhome pumped water system. The exisiting system uses a pressure
switch which was okay with the old pump but a new uprated pump is
causing problems and the recommended solution it to fit a pressure accumulator

Of course I could just spend lots of dosh and buy the recommended one
but it's more fun to try and do it on the cheap. ;-)

http://www.ebay.co.uk/itm/SHURFLO-Ac...item27d2223cd7

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,

Have you ever tried jumping on one? They are incredibly strong. Yes, they
can get pierced but that's easy to prevent.


secondly, the 'proper' accumulator has a diaphragm inside it, water on
one side, air on the other, it's the compressible air the other side of
the diaphragm that acts as the buffer,

I guess that the diaphragm stops the loss of the air cushion caused by the
air getting dissolved in the water but it would be easy to "recharge"
periodically.


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,

Well that might be the easiest solution! Not as much fun though. ;-)

Tim