Richard BealeHi raybuckner,
I agree with both 11echo and Jop, but I would like to expand on their answers. I believe that the answer to your question lies primarily in the state government legislation. In Alberta, Canada, I know of two government legislations that speak to pressure equipment, which includes process piping. The first is the Safety Codes Act and the second is the Pressure Equipment Safety Regulation; the second of which is more specific to your question. We also have the Engineering and Geoscience Professions Act which requires that all engineering work done in Alberta must have the stamped approval of a licenced professional engineer, or (unique to Alberta I think) a licenced technologist that has passed the scutiny of a joint engineering society and technology society panel of examiners. No doubt Minnesota has similar, if not identical, legislation, as do all states and provinces in North America and other countries throughout the world. By these acts it is a legal obligation of owners, designers, manufacturers and constructors to meet the requirements of the listed codes, which includes B31.3. It is also a legal requirement to have traceability of compliance. As Jop has said, the B31 codes speak to stress analysis. Such things as expansion loops, anchors and guides, and bellows and expansion joints design and placement clearly require the services of an experienced stress engineer. I cannot see how code compliance can be documented and traced, in accordance with government regulations, by any other means than that of having a professional engineer stamp the piping configurations as is detailed in the piping arrangements and/or the isometrics. Additionally, with respect to 11echo, a civil/structural engineer requires the input of a stress engineer as to the static and dynamic loadings that will be imposed by the piping on the structure in order to design their structures and piling.
Another code compliance requirement that I can think of, that can also only be ensured by an engineering review of the piping layouts, is pressure safety. For instance, when installed on the piping systems, PSV’s that protect equipment cannot be located any further away than a 3% pressure drop between the equipment and the PSV.
Leaving aside any legislation, I think that it is almost common sense that if an engineer is required to do, oversee, or approve the designs, then it is also necessary for the engineer to sign-off on and stamp the designs. I can’t speak for the rest of the world, but in Alberta it is common practice to stamp the piping designs; so-much-so that constructors will refuse to build without them.
The only debate I’ve seen recently surrounding the stamping of piping drawings is whether or not to stamp the piping arrangements or the isometrics or both. This, however, is a debate generated by the advent of 3D CAD and not a debate as to whether or not to stamp piping drawings, but rather which ones to stamp.
In the past, in the manual and even the 2D CAD drafting world, it was common practice to stamp the piping arrangements only and consider the isometrics as secondary construction documents that reflected a compilation of already signed and stamped information, and not requiring of stamping. But that was when we were doing fully dimensioned plans and sections that included all anchors and guides placement. Nowadays, with automatically generated isometrics from the model databases, piping arrangements are often plans only with minimal detail or not produced at all, and the isometrics are no longer generated by the efforts of a manual drafter from the copying of the piping arrangements and compilation of BOMs by reading the piping specs.
Rather, commonly speaking, because of the automatic isometric generation, what I see now are stamped isometrics issued for construction, and unstamped piping arrangements that are plans only issued for information, although, this does vary somewhat according to client requirements.
For your information, I have attached the below links to the Alberta legislation to which I have referred. No doubt you can do a Google search and find the applicable Minnesota legislation.
http://www.qp.alberta.ca/documents/Acts/S01.pdf
http://www.qp.alberta.ca/documents/Regs/2006_049.pdf
http://www.qp.alberta.ca/documents/Acts/E11.pdf
Please let us know of any developments and/or decisions that the engineering company(ies) you work for make. I think we’d all be really interested in a follow up of the rational and concerns behind not wanting to stamp the piping drawings.
Best wishes,
Flowr8