•ADI Systems
•AEC Engineering
•Aker-Kvaerner Process
•Ambitech
•AMEC
•AMG, Inc
•Apex Engineering
•Anderson Engineering
•Apex Engineering
•Benchmark Engineering
•B.E. & K. Engineering
•Bibb & Associates
•Biothane Corporation
•Black & Veatch
•Burns McDonnell
•C. J. Schnieder
•Delta T Corp
•Denco Inc
•Dow Engineering

•Duke Fluor Daniel
•Fluor Daniel
•Fore Runner
•Foster Wheeler
•Frucon
•Harza Engineering
•GEA Evaporation
•Graycor
•H & M Engineering
•Harris Company
•Haskel Company
•Ibberson Engineering
•ICM
•Jacobs Applied Technology
•Jacobs Engineering
•Katzen & Associates
•Kvaerner Songer
•Lockwood Greene
•Lurgi-PSI