Anyone an industrial/maintenance electrician who works on Hydraulics and Pnuemeatics stuff as well as electrical? I've been doing some research in terms of jobs, and a lot of the job listings I see says Hydraulics/Pnuematics are a plus, when applying, and some even say HVAC knowledge...why is that? I can't figure that out. So how do you learn these skills? Is some of it covered in the apprenticeship, or do you have to go about learning it by other means?