THOMASVILLE — Jim Wilden’s big idea keeps getting bigger.

In 1955, Wilden revolutionized an entire industry with his invention of the air-operated double-diaphragm pump. The California company that bears the former steel foreman’s name has grown into a global business that expanded its operations to Thomasville with the acquisition of Griswold Pump Company on Sept. 18.

“We were looking to move beyond the air-operated pump business,” said Darren McGuire, a former Wilden Pump and Engineering marketing director who was named Griswold’s managing director. “We knew there were some good companies out there with great service, great products and (who) had a real name for themselves.

“Griswold fit the bill for us.”

Griswold’s specialty is centrifugal pumps that can move a variety of liquids, including gasoline and milk. The Thomasville-based company, featuring a payroll of 35 employees, posted sales in excess of $10 million last year.

Jim Wilden’s first pump, built in his backyard, originated from the need for a way to flush water out of an underground room at his steel factory. Additional products that stem from his invention generated $130 million in sales in 2006.

“Wilden does more than 60 percent of its sales internationally,” McGuire said. “So overnight, Griswold, whose business has been 95 percent U.S. and Canadian based, will immediately have access to the rest of the world through (Wilden’s) distribution network. In fact, we’ve gotten inquires from Australia, Indonesia, Vietnam, China and the list goes on.”

McGuire expects Griswold, which will maintain its name, to grow exponentially, depending mostly on its current employees to start the process. Griswold began its independent operation in 1997 after its owners broke away from Fairbanks Morse.

“Everybody in the building is going to have to play a significantly larger role as we grow to five, even 10 or 15 times our current size,” he said.

Preparations for increased volume are under way, including discussions about expanding Griswold’s facility at 107 Plantation Oaks Drive.

McGuire, set to move to Thomasville today, expects the transition to continue smoothly.

“It comes down to the family culture in the way Wilden operates and the way Griswold operates,” he said. “It’s nearly identical in the way employees, distributors and customers are treated and valued. It’s a perfect fit because we saw a great company and a chance to grow.”