It varies by state, but generally the requirements are a BS or Engineering Technology degree, relevant experience in the field of license, and passing the PE exam. Not sure what you mean by saying everybody can be a professional engineer; surely there's a license/certification for qualified personnel to stamp/approve designs?

I (being in the states) would not hire a pipe stress company if no one was a PE. I'm paying for an engineering assessment/report; if they're just going to toss the model reports at me they don't offer much value.

"Not sure what you mean by saying everybody can be a professional engineer; surely there's a license/certification for qualified personnel to stamp/approve designs?"

The profession of mechanical engineer is completely open,
there are no licenses, permissions, certifications etc.

That's really surprising considering how anal Europe is about most things

Generally, if you're going to act as a consulting engineer, you'll need a PE license in the state(s) where the projects are to be built (not necessarily where your home or office are). Many states also require a PE license for your business as well. The individual PE license may require you to take tests and document your education, etc, but you just need that in the first state you're registered in. The corporate licenses are usually just a matter of filling out forms and paying money.

Many states have industrial exemptions, where if a business is doing engineering for its own facilities, the engineers involved don't need to be registered, and that probably applies to a fair percentage in this field- that would apply to people working for refineries, etc. For people working under the supervision of a PE, the work can be sealed by that PE.

All of the engineering licensing varies from state to state, so pick the state of most interest and start looking into the requirements there, which can generally be found online.

You may run into a chicken-vs-egg situation trying to establish residence and get visas to work and trying to get work going to establish a residence.

"Not sure what you mean by saying everybody can be a professional engineer; surely there's a license/certification for qualified personnel to stamp/approve designs?"

In Spain, and in industrial engineering at the very least, you must be a member of an engineering professional society and have finished a master's degree in industrial engineering to be able to stamp designs.

Also, there are some initiatives to bring PEs to Europe: https://www.aqpe.org/?lang=en

Thank you.
Do you think there is a chance to start business before visit the US?
Finding a company willing to cooperate remotely isn't easy, but it can be a good deal for them, engineering calculations can be performed remotely without loss of quality.

I'm not as familiar with the business side, but I believe in order to apply for the business PE license you need at least one person with a PE to be a part owner or maybe in a position of management. Not sure what the rules are; check the most applicable state you're looking at it.

I think you'd have a hard time setting up a business in your desired state with no PE and no presence in the area.