There is indeed something to be said for a pioneering spirit. As long as there are no disputes among bidders or other parties etc. to a construction project, nor unanticipated problems with the performance of any chosen/supplied elements of a project once built, I guess there is for that matter arguably even little need for “consensus standards” (nor for that matter unquestioned conformance to same). I am however aware that pvc “welded” joint end pipes (i.e. solvent cement welded joints) were once specifically included in the original C900 standard (from the first edition in 1975), but they were removed in the 1989 version of that standard (with the statement in the Foreword to that revision, “Provisions for solvent-welded joints throughout the standard were deleted.”) I believe also that when the first edition/of brand new AWWA C905 standard was released in 1988, for 14” and larger pvc pipes, there was no reference whatsoever in that new large pipe standard to any solvent cement, nor for that matter any other form of pvc welding. That new standard even contained the specific requirement under Sec. 3.6 Joints, “A gasket joint shall be provided with each length of PVC transmission pipe.” However, I believe reference in the C90X series of standards to welding or fusing was again variously revived in later versions of the standards to present, but then it appears specifically only then/at least specifically directed to fabrication of pvc fittings, and then (with QC/QA for same etc.) to be under “factory” conditions, as I believe is noted in the PPI letter.
From a technical perspective pronounced thermal, Bourdon, and Poisson behavior (the latter e.g. as advised by Mr. Robert Hucks [e.g. see thread
.], in a July 1972 AWWA Journal article as, “Since PVC pipe moves axially as well as circumferentially in response to pressure surges (“Poisson’s ratio effect”), pipe may undergo scratching of the outside when buried and in contact with sharp stones in the backfill. This area requires further study…”) could perhaps result in some different responses in a system with at least some relatively long sections of welded pipes than in a conventional rubber-gasketed joining system. I do not know if these behaviours/this history has necessarily any specific relevance to the current dispute, but it perhaps makes it a little hard to believe given same that all members of the standards committees do not have any opinion as to need for minimum requirements/basic philosophy for/ of basic sealing to pipe ends etc!
[BTW I had occasion to see some fascinating construction just a very few years ago, of course now leading into this 21st Century, of a brand new open-air “aqueduct” to transport water a considerable distance in the Andes mountains of South America. While this new aqueduct employed some modern engineering materials e.g. an underlying impermeable membrane and steel-reinforced concrete sections with expansion joints, I suspected it would function in much the same way (i.e. with general success) as had similar aqueducts built in the area for hundreds of years. The only reason I was there was to help them design and install a quite large pressure pipeline siphon, that would allow the aqueduct to pass under a quite deep canyon (a technology I don’t believe at least quite as readily available to ancient engineers). I wouldn’t even be a bit surprised if there is also still some “wood” out there still functioning pretty well as pressure pipe, and/or as a sort of swelling/reasonably durable lining for metal etc. pipes, in an era when cement mortar lining technology was not well available/understood. I guess it remains to be seen whether many “new” products will provide similar value.]