Document rX4GvDRK99z4OMqww2572zME

CONFIDENTIAL Division Headquarters December 28, 1961 FDA # 54 PLAINTIFFS - EXHIBITS^ JMMC-244 TO: 322-S, 321-S, 12, 1071 PERSPECTIVE It is salutary we feel, to step back from the heat and action of the day's battle and view your adversary long range. Often it is revealing because points of vulnerability sometimes stand out quite clearly. The service record of cast iron pipe in the past and the promise of future service life can be "appreciated" in practical perspective when one reviews a simple chronological listing of Time vs. Events that illustrate the evolution of cast iron pipe. Notice the trend in wall thickness. CLASS 150 TIME EVENT WALL THICKNESS 6" 12" Circa I664 Versailles, France In- | stallation. 1 2L" " 1803 First cast iron laid in U.S. in Philadelphia. " 1850 " 1881 1908 1924 Vertical pit casting start ed in U. S. American Water Works Association formed. First AWWA Specification covering Pit Cast Pipe Centrifugal casting started in U.S. on production basis PIPE O.D. F/PST STANDAPD ON WALL thickness j P/PE ID. I I J > 0.51" .68" 1.04" 1927 Federal Specification covering centrifugal cast pipe (WW-P-421) .37 .50 .76 1952 ASA Specifications covering centrifugal cast pipe .38 .48 .73 1955 Federal Specification (WW-P-421a) changed to agree with ASA 1957 Present Cast Iron pushing higher strength metal (21/45) Rumor about Ductile Iron .35 .41 68 r 1 CONFIDENTIAL -2 December 28, 1961 Corrosion of Cast Iron of Various Compositions "The many experiments on a laboratory scale, using agitated water as the corroding agency resulted in the conclusion that all cast iron of com positions usable practically in cast iron pipe for water and gas--that is, capable of being cut, drilled and tapped--corroded at substantially the same rate, so that the problem of preventing corrosion remained one of protection rather than composition of iron." (Quotation from ASA - A21.1 - 1957 "Manual for Computation of Strength and Thickness of Cast Iron Pipe"). Observations 1. Standardized wall thicknesses have been in use for only the past 54 years. Wall thicknesses of pipe before 1908 may have been much thicker. 2. Cast Iron Specifications have permitted a 25 to 30 per cent reduction in wall thickness (depending on size) from pit cast to present ASA thicknesses. 3. Cast Iron pipe as supplied today (centrifugal casting) enjoys an actual service record of 38 years (since 1924) in the U, S. and not 100 years plus as suggest ed in advertising, (note Transite dates from 1930). 4. In view of the comment on corrosion, it is doubtful that today's cast iron pipe will provide a similar long service record (on the average) as pipe of the 1800's has provided. Place this in TR 200-A under Competition. OAW/bgs 0. A. WIRSIG