Document rxZz1Gmv0B7K76p3Eo8Zo5B7

NIMA Molded Section Report at Absecon, October 10, i960 E. C. Shuman - Chairman The Molded Section held a scheduled meeting in New York on June 22, I960, for which Minutes have been distributed. Of interest to the meeting today are the studies made of the Federal and Military Specifications for molded insulations and cements and to special specification; such as Corps of Engineers, CS-301.21, for underground systems. On the basis of these studies, Secretary J. M. Barnhart, in cooperation with Ray Parlett, has written to the appropri ate specification authorities requesting consideration of suggested changes. In general, the suggested changes bring the government agency specifications into line with specifications and test methods of ASTM where most NIMA members also work diligently. The specific specifications are listed in the June 22, I960 minutes. It should be recognized that our concern in both ASTM and gove mment is the development of realistic test methods and sampling procedures which keep the cost of testing at a minimum consistent with good quality control and which keeps manufacturing costs at a minimum consistent with specified performance. As an example; former length requirements were 18 or 36 inches minus zero plus 1/4 inch. With recent attention to better fit of adjacent pieces in applications, requirements for square ends induced more care in end trimming which frequently had not been done. To end trim meant shortening the piece so that a length requirement of minus zero tolerance would mean rebuilt or new molds for most manu facturers, From a practical standpoint, a slight change in tolerance to -1/16 inch permitted end trimming for square ends without extensive mold changes. In general such specification changes suggested by NIMA have met with good acceptance, since they are based on reasonable modi fications aimed at keeping the cost of insulation down. The writer was asked to present the NIMA approach to dimensions and standard nesting sizes to ASTM Sub-committee S-VIII on General Standards. These were the dimensional tolerances circulated to NIMA on which there was general agreement. From this joint discussion, the proposed molded pipe insulation and block variations were generally agreed upon in this Sub-committee as NIMA proposed* However, some users of insulation emphasized that their acceptance was on a basis aimed at getting standards started rather than a basis for purchase. This implies that closer control of dimensions will be expected in the future.