Andy Dingley wrote:
On Sun, 24 Oct 2004 17:19:29 +0100, "JM" wrote:

The installation instructions for the machine (http://tinyurl.com/5bru9)
specifically advise against using tools to tighten the connectors so that
sounds right to me.

I use tools to tighten these up (and more often, to unscrew them !).
However I'm using a curved jaw wrench of the right size. If you can
apply enough _even_ compression to get a grip, yet still hold the nut
circular, then you can apply quite some force without damage.

OTOH, if you go at it with flat-jawed Moles from opposite sides, you
distort the thing. Then it breaks in no time at all. If you're really
lucky you get to break the plastic valve body on the input side of the
machine.

Sorry I wasn't clear.
I'm not happy applying as much torque as I can get on the plastic, with
just hands and a bit of towel, when the compression seal on the valve
is taking all that torque.
I was just meaning to restrain the valve from turning.