Wilden Pump & Engineering has acquired Griswold Pump Company, Thomasville, GA. With the acquisition, Wilden, a division of Dover Corp., will have annualized sales of more than $140 million.   ; Griswold manufactures ANSI centrifugal pumps for use in the petroleum, petrochemical, wastewater and pulp & paper industries.   ; Wilden, whose international business exceeds 60% of total sales, has locations in Dusseldorf, Shanghai, and Chennai, respectively. International growth will be a highlighted area in Griswold's strategic plan going forward.   ; Wilden says it will use its distributor network in introducing the Griswold line to a worldwide market.