42 Engineering; Consulting in the field of mechanical engineering; Custom design and engineering of HVAC, mechanical, process piping, ventilation, plumbing, and building automation control systems; Engineering design services; Engineering services in the field of HVAC, mechanical, process piping, ventilation, plumbing, and building automation control systems; Industrial design services; Mechanical engineering; Planning and layout design services for HVAC, mechanical, process piping, ventilation, plumbing, and building automation control systems in facilities, buildings, factories, and manufacturing plants