Design Engineering

A design engineer is a general term that covers multiple engineering disciplines including electrical, mechanical, chemical engineer, aeronautical engineer, civil and structural /building/architectural.
Although, there is no specific design engineering degree listed by the National Center for Education Statistics, individuals who graduate with a degree in one of the main branches of engineering - such as mechanical, electrical, civil or computer, can make career choices that focus on design. Possible degrees include a Bachelor of Engineering, a Bachelor of Science in Engineering, a Masters in engineering, a Master of science in engineering, and a doctor of engineering. Hopefully, design engineers can expect to take classes in calculus, physics, chemistry, writing, computer science and communication in addition to their engineering courses.

You can refer to the links mentioned below:
http://edpti.com/PipingDesignTraining.aspx
http://www.ssitedi.com/Pipe_design_engineering_course.html
http://www.cadc.iitb.ac.in/
Scope:
Piping constitutes of 40~45% of total process plants (Only refineries, petrochemical and fertilizers complexes). Piping is only relevant in oil and gas downstream industry, and it's known as Plant Design and Piping Department. There are 3 kinds of piping engineers:
1. Layouts.
2. Materials and
3. Supports (stress).
While supports or stress engineers need good foundation on mechanics of materials, they play only 10% of the role, they only interact with layout and structural engineers, on the other hand, layouts plays a prominent role in whole process plant development, layouts interacts with all disciplines, layout engineers need good understanding of cross functional teams and interdisciplinary teams, layout engineers are answerable to all engineering teams viz mechanical, chemical, metallurgy, civil and project management.
Frankly speaking piping is a hot cake job during peak oil demand, but during recession it's the worst job, skills of piping engineer are applicable nowhere, their knowledge is only useful where several kinds fluids flow in piping system namely acids, carcinogenic liquids, poisonous gases, caustic liquids, corrosive fluids, hydrogen and very high-pressure jet, all these coexist in downstream industry not anywhere. If the world is moving away from Oil, you will be the first person to lose the job.
Someone of the tedious jobs by piping engineers will be taken up by software such as SmartPlant will reduce the burden of MTO creation, thus the overall job of piping will get reduced, thus less and less manpower is required for piping in future.