After 4 1/2 years with Fairbanks, Morse & Co. back in the '50s, Myles spent 38 years with "Durco", the Duriron Company Inc., which  became "Flowserve Corporation. Myles served in many capacities: Sales Engineer, District Manager, Caribbean Area Manager, Regional Manager over 1/3 of the US with responsibility for pump and valve sales, Sales & Marketing Manager for the Valve Division in Cookeville, TN, and finally Business Unit Manager over two regions (Gulf Coast and Southeast), responsible for valve and actuator sales. In these activities he gained knowledge on process equipment ranging from pumps, valves, actuators, to filters, compressors, mechanical seals and reactors. He became familiar with the process industry across North America. He gained market knowledge on many corrosive and hazardous services. He hired, trained and motivated sales engineers, distributors and representatives in most markets in North America.

He was named "Man of the Year" by the Valve Manufacturers Association Of America in 1987 for his work calling attention to the "Bogus" valve issue.

As founder and originator of Durco's authorized repair shop program, the "Black Tie Shop" program, Myles gained knowledge of the entire valve repair industry. This led to his being the Founding Chairman of the Board of the VRC, the Valve Repair Council, an arm of the VMA

Retiring early in 1998, Myles saw the need for his knowledge and established Myles Sweeney & Associates, LLC.