Hi Jim,
I know the Weber gas bbqs come with regulators that are designed to connect to a Calor patio gas type bottle, using the 27mm clip on connector. Theres quite a bit of info here on the Weber Q bbqs
https://www.bbqs2u.co.uk/blog/weber-q-b ... 00-bbqs-n9This product should attach to your large 47kg bottle
https://thegascentre.co.uk/propane-regu ... Gwodpl4OCgYou'll then need to remove Weber's regulator from the rubber hose and attached the hose directly to that product with a jubile clip.
Probably best to talk a local gas centre to confirm with a professsional, but i'm sure Weber gas bbqs use a pressure of 37Mbar.
Hope that helps, you'll cook a lot of food with that gas bottle!