Dear Frineds

Can any body help me what are the galvanized iron bolt sizes to be used with PN 10 flanges. I have a pumping station for a raw sewage water treatment plant with PN10 valves and pipes. How much clearance should I use between bolts and flange holes. is 2 mm enough.
Does anyone have a chart for the anchor bolts sizes to concrete foundation, how much hole should I specify in the concrete base.

You quick reply will be highly appreciated

Regards

Basha