I wouldn't know for sure, but I would think that so long as it is before the membranes it doesn't matter....does it
![Huh ???](http://www.cleanitup.co.uk/smf/Smileys/classic/huh.gif)
I'll have a look and see where my own is, but I'm sure it is before it goes through any of the filters..........
Nope, I just went out and had a look, pressure guage is just before the membranes and after the pre-filters.
So don't worry
![Wink ;)](http://www.cleanitup.co.uk/smf/Smileys/classic/wink.gif)
Ian