I have a 30" diameter pipe that is supported about every 5-6 ft using bolts in a steel pipe support. As you can see in the attached photo, there is a pretty good size gap between the bolt/nut and the top surface of the pipe support, and also between the two faces of the interface. My question is where can I find a good resource on allowable gap spacing between these types of pipe supports (these pipes are galvanized carbon steel and are for transporting water)? My gut tells me to place a shim between the bottom gap and leave the top gap open, but this is purely speculation without some decent documentation on the allowable spacing. Thanks in advance.