Below is a list of Stainless Steel Manways manufacturers from Clarkston, Michigan. A stainless steel manway is the lid that serves as access point to the inside of a vessel, usually consisting of a flanged nozzle with a cover plate. Also called a “manhole,” the size, style, and number used may vary from application to application. Stainless steel manways might be selected as part of a custom design or may be specified as an addition to an existing vessel.