Dover acquires WellMark Dover announced that its energy segment has acquired The WellMark Company headquartered in Oklahoma City, Oklahoma. WellMark is a leading manufacturer of valves, instrumentation and chemical injection pumps serving the oil and gas industry. The company also announced that WellMark will be merged with Norriseal, a long standing business within the Energy segment. WellMark expects to generate revenue of approximately $55M in 2014. Terms of the transaction were not disclosed.