In this paper we give an explicit
description of valuation rings compatible with certain infinite preprimes of a field.
These results are essentially constructive versions of the results of L. Brocker and E.
Becker relating fans and valuations. We discuss a number of examples in detail,
including the higher orderings recently introduced by E. Becker. One of several
applications is a generalization of the theorem of Brocker-Brown characterizing
superpythagorean fields.