I have a Bombas ITUR F3 pump with a pressure control valve on top.  Pressure reads between 6 & 7 bar which I now understand is far too high.  If I remove the domed plastic top of the controller will I find adjusters underneath? My query is - is it safe to remove this top or is there some enormous spring contraption there which will bite my hand off?  If safe,  then guidance will be appreciated to get down to a more reasonable 3 bars.  Many tks in antic.  Cannot find anything via Google.

Er, yes.  Would you care to help by expanding a little?  It is a full industrial and commercial site and I have spent two hours trying to find an answer to my query.  If you know the site so well then I'm sure you can focus down to the area I need to concentrate on.  At the mo I am no more the wiser.  Thank you for your consideration.

What is the power of the pump and from what depth is it pumping - maybe it is overrated for the house?

What type of control ? a press control - see picture?
Generally these are not adjustable (I have seen a couple that are but they are not very common). They usually work at the máximum pressure of the pump so it depends on the pump power. Most domestic pumps manage to pressurise up to around 3 bar. If you have a powerful pump it will have a higher pressure.

You may end up having to put an inline pressure control valve in that will reduce the input pressure to the house - I have had to fit several of these to agricultural wáter supplies in the Burgar valley.