There is no requirement for a "chief engineer".
In general, by law all technical submittals are required to be sealed. Here is an example:
"Every licensed professional engineer shall have a reproducible seal or facsimile, which may be computer generated, the impression of which shall contain the name, the license number of the professional engineer, and the words "Licensed Professional Engineer of Illinois". A professional engineer shall seal all documents prepared by or under the direct supervision and control of the professional engineer. Any document that bears the name of a professional design firm, rather than bearing the name of the individual licensed professional engineer responsible for the document, shall be deemed an invalid seal. The individual licensee's written signature and date of signing, along with the date of license expiration, shall be placed adjacent to the seal. Computer generated signatures will not be permitted."
Note there is no exception for industrial work.
However, unless submittals are submitted to government agencies, there is no enforcement of the seal requirements.
Lastly, you can not call yourself an engineer unless you are licensed:
"(o) "Professional engineering practice" means the consultation on, conception, investigation, evaluation, planning, and design of, and selection of materials to be used in, administration of construction contracts for, or site observation of, an engineering system or facility, where such consultation, conception, investigation, evaluation, planning, design, selection, administration, or observation requires extensive knowledge of engineering laws, formulae, materials, practice, and construction methods. A person shall be construed to practice or offer to practice professional engineering, within the meaning and intent of this Act, who practices, or who, by verbal claim, sign, advertisement, letterhead, card, or any other way, is represented to be a professional engineer, or through the use of the initials "P.E." or the title "engineer" or any of its derivations or some other title implies licensure as a professional engineer, or holds himself out as able to perform any service which is recognized as professional engineering practice."
Thats why people call themselves Project Managers, Associates, or whatever. I guess these terms sound better whatever.
There is a definitely a need for engineers to self police their profession. Have you ever heard of a doctor or lawyer practicing without a license?