| Sorry this isnt meant as a hijack, When I went invert a while ago on for me a new twinset there was a discussion on here about how to shutdown, I stated that I would go for the rh valve (same reasons as you - most likely) and I'm sure I recall one of the DIR guys/instructors saying "go for the isolator", I will see, when I have a moment if I can find it in the archives.
I'm still not sure though that item 11, close and open isolator will tell you if the manifold has gone or not, surely only by closing both pillar valves will you then know, gas can only escape through the manifold whilst you have gas in the tanks, shutting the isolator will tell you nothing about the manifold. It wont stop the gas leaking from it.
Matt |