Murphy Company Mechanical Contractors and Engineers, St. Louis, MO, has named Dave Hardin , P.E., as chief operating officer. Hardin will retain his current title of executive vice president. Hardin joined Murphy Co. in 1976 and has more than 26 years experience in the mechanical contracting industry. Murphy Co. is a diversified firm serving as constructors and engineers for the mechanical and industrial construction markets, including maintenance and service. The company completed nearly 900 projects in St. Louis, Denver and other national locations last year.