Diameter limitation for SS anchor bolt in API 650 tanks 1

There's a minimum size given in the section on anchor bolts.
I'm not aware of any maximum. Quite often, bolt sizing is limited in practical use by the size of the anchor chairs required to distribute the load or by embedment considerations.

Are SS anchors specifically required and in the Tank Data Sheet in table 2? Otherwise you are stuck with Section 4.7.b. Also, be sure to not use over 55ksi yield strenght anchor bolts per 4.7.b. As the esteemed colleage JStephen says, there is no maximum size for anchor bolts but given the need to also design the anchor-to-shell connection, embedment strength and foundation capacity, very large anchors are seldom seen. What size is your tank, what type of foundation are you looking at, what is the soil capacity, how large are the seismic factors?