Job Description. Do you like travel and have a background in "hands-on" Mechanical Engineering. If you do, then we have the job for you. The job with OST Services (a subsidiary of LISEGA, Inc.) involves the Jr. Field Service Engineer ideally having some experience with pipe supports, restraints and snubbers. The work will be performed at non-nuclear and nuclear electrical generating facilities, waste treatment plants, paper mills, Petro-Chemical ...