Document YGBaOOqj2nykMEx7Vv3RoYX9V

April 27, 1956 Mr. Bucskews';!: SUBJECT: The Value of Pulverised Paste in the A/C Pipe Furnish Several weeks ago, you and Mr. Lanz discussed at considerable length the Value of Pulverised Waste in the A/C Pipe Furnish. A3 a result of your conversation, 3ome experimental runs were made at Santa Clara in order to get data on the subject. The data has now been secured and based on it, together with other information, Mr. Lans has prepared a report on the Value of Pulverized Waste in the A/c Pipe Furnishes* His report is attached hereto. You will find it Very interesting. Based upon the information therein, it is my recommendation that we change the Making Particulars for St. Louis and Santa Clara to limit the amount of Pulverized A/C Waste returned to the pipe at those plants to a maximum of six per cent, and at Ambler to a maximum of ten per cent. Before going forward with the change, will you please advise if you would accept this recommendation. CRH:ec Att. cc - Messrs/Euczkowski (2) 'Kuehlock ''Maloney `'Angstadt 'Meek ybstrowski Naeman Rhoades 'Taylor 'Gear Kaco Malone 'Hlnlcel / rLanz v/ File CTD001020 FILLt/&: April 27, 1956 SUBJECT: The Value of Pulverised Vaate in the A/C Pipe burnish 3 discussed at considerable the .A/C Pipe Furnish. As erinisntal runs were .r.ade at subject. The data has now been secured and based on it, together with other information, Hr. Laws has prepared a report on the Value of Pulverised taste in the to the pipe at tho3e plants to a maximum of sis per cent, and at Ambler to a maximum of ten per cent. Before going forward with the change, will you please advise if you would accept this recommendation CRH:ec Att. cc - Messrs / Bucnkow3lci ^Muehlock ^Malcnoy ^Angstadt */'Meel: ^Ootror/ski Kuaman Rhoades -^Taylor "'Gear '/Maco Halone ^Klnkel / vLanz \S File (2) CTD001021 April 27, 1955 SUBJECT: The Value of Pulverised Waste in the A/C Pipe Furnish Surrrni'vi?. Pulverized Wants when added to the A/C Pipe furnish reduces the density of the finished pips and thereby reduces strength. Additional fiber reinforcement must be added when the amount cf Pulverised '-.'asfee ia increased to overcome the loss of strength duo to the lfv?ered denaity. It was doterr.ined that the cort of the additional fiber nearly if not completely offsets the savings due tc the use of Pulver ised Waste. Became the use of Pulverised haste ir. the furnish results in lo*.:cr density pipe, and because lew density pipe are a potential source of difficulty due to weepege and/or leakage, and because it costs little if any more to make higher density pipe by minimizing the use of Pulverised Waste, It is recommended that the use of Pulver ised haste be United to a Eaximun of si:: per cent at St. Louis and Santa Clara. At Ambler, where higher densities are obtained because no silica i3 used in the furnish, it is recommended that the use of Pulverized Waste be limited to a maximum of ten per cent. It is not recommenced that Pulverised Warta bo.eliminated from the A/C Pipe furnish because it is desirable to use as much scrap as possible, to prevent it from accumulating and also, some Pulverized Waste in the furnish undoubtedly aids formation and filtration. History? \ Several months ago, I discussed with Hr. Buczkovjaki the problem J of determining a proper value to placs upon Pulverized Waste when it is used in a furnish for A/C Pipe. I v?a3 of the opinion that, since Pulverized Waste had been found to ha/e a relative value of 5 in Laboratory tests, it should be possible to use ICO pounds of Pulver ised Waste to replace 5 pounds of C?;G/3 (relative value ICO) and 95 pounds of cement-silica mix (57 poinds cement and 33 pounds silica). Using Santa Clara costs, for example, the value of 100 pounds of Pul verized Waste isould be calculated as: (5X.1712) + (57)(.0089) + (38)(-0058) - $1.62 or 0.0162 per pound At Santa Clara, no financial value is given to Pulverized Waste. Thus, for each pound of Pulverized Waste used over and above the amount in the standard furnish, a profit of 0.0162 should result. If Plant Ko. 6 used 100 tons of Pulverized Waste in a month, this should represent a saving of $3*24-0 over the cost of furnishes if no Pulver ized Waste had been available. (100)(2000)(0.0162) $3,240 Mr. Buczkovfski questioned whether v;e had any data to prove the foregoing hypothesis, and, having none, we agreed to ask f-lr. C. R. Mselc to make a trial run at Santa Clara in which Pulverized Waste with an assumed relative strength of 'j would be* used to replace a calculated equivalent amount of fiber., cement and silica. - -:^S A CTD001022 -2- Dlscussion: Uuivlr.:.; the experimental run which was-mace, the fiber blend In use vrc.,'3 C&G/3. 623 pound,-; CoG/4, 375 pounds; and Blue 375 pounds. An experimental furr.ich, No. 54S v:as used with a regular production furnish, No. 54. These were: <K Fiber blend, pounds Pulverised waste, pounds Cement, pounds Silica, pounds Bo. 5* , ~71037"br',1i/Ht 800 533 204 1,,-,4 257 ';7# 715 477 t 3,3 -z-\ 34 45 Total 1713 1713 Furnish No. 543 la identical to furnish No. 54 except that $ pounds of fiber, 65 pounds of cement, and 56 pounds of silica have been replaced with 150 pounds of Pulverised Baste. The effective* ness of furnish for both To. 54 and No. 5!:-S is 1377 which means the 150 pounds of Pulverized Baste with a relative value of 5 has a calculated reinforcing value equal to the 9 pounds of fiber blend plus the 85 pounds cf cement and the 56 pounda of silica. The two furnishes were made into 6 inch. Class 150 pipe using Identical been prca.eu.res for both furnishes. Original data obtained by Hr. Knelt are shorn on the attached data sheet. Average strength values for the two furnishes are shown In the following table. Eurstlng Pressure,P.S.I. Mod.of Rupture.Bursting,?.S.I. Crushing Load,Lbs.Per Ft. I-*od. cf Rupture, Crushing, P. -3.1. Density, P.C.I. 3570 8520 7700 0.0624 3300 7290 7140 0.0606 An examination of these average values shows that pipe made with the experimental furnish were weaker in bursting and crushing than pipe made with the regular furnish but also that the experi mental pipe -were lower in density than the regular pipe. Three conclusions are possible: (1) the e::porimontG.l pipe were weaker because the Pulverized Baste was not the equivalent of the fiber, cement and silica for which it was substituted, or (2) the experi mental pipe were weaker only because the density was lower, or (3) the experimental pipe were weaker because of a combination of (l) and (2). It has been found in both the TiN and X&M Laboratories that, when other factors are held constant, the strength of an asbestos- cement product i3 proportional to tho square of the density. Thus we can estimate what strength values :?ould have been found for No. 54 if tho density had been exactly 0.0620 pounds per cubic inch by CTD001023 ' -3 multiplying the values actually obtained by (0.0620)2/(0.0624)2. Similarly, the values for No. 54S can bo corrected to a density of O.C620 pounds per cubic inch by multiplying by (0.0520)2/ (0.0505)2. The calculated strength valuoa for both furnishes at a density of 0.0620 pounds per cubic inch are shown in the followln^ table: Eursting Pressure, P.3.1. Mod.of Rupture,Bursting, P.S.I. Crushing Load, lbs.Per Ft. Mod.of I-hjpture,Crushing, P.S.I. Calculated Values at 0.0520 i\0* J5*'* 767 3520 767 3450 8410 8360 7600 7470 The values are remarkably close, being within two per cent of each other in all cases. It is nov; possible to say with soma assur ance that the right conclusion is the second one: (2) the experimental pipe were weaker only because the density was lower. From tills we can infer that, if density can be maintained constant, a relative value of 5 for Pulverised Wa3te is correct and 100 pounds of Pulverised Waste can be considered the equivalent of 5 pounds of C&G/3 and 95 pounds of cement-silica ml:: in furnishes for A/C* Pipe. In this run, the furnish with the largest percentage of Pulver ized Waste had the lo-west density; we have noted in several experiraontal runs that the addition of Pulverised Waste to pipe furnishes has resulted in reduced density. From the meager data which were available, I estimated that the use of one per cent Pulverized Waste reduces the density of A/C Pipe by 0.00025 pounds per cubic inch (the value for this run was 0.00021 P.C.I.). Thus, In A/C Pipe, v;e cannot add Pulverised Waste to the furnish and maintain constant density; this complicates the question of the value of Pulverized Waste in the furnish for A/C Pipe* If other factors are constant, the strength of an asbestoscement product depends on the effectiveness of furnish and the density. The use of Pulverized Waste in the pipe furnish adds to the effective ness of furnish by the relative value' of 5 but reduces the density by 0.00025 pounds per cubic foot for each one per cent used; these tv/o factors tend to offset one another, the relative value of 5 tending to increase strength and the reduction in density tending to reduce strength. To determine the net effect of Pulverized Waste on the breaking strength of pipe an empirical equation was developed. (See Appendix). Ey using this equation It was possible to calculate the estimated bursting pressures for 6 inch. Class 150 pipe made from furnishes using varying amounts of the fiber blend and Pulverized Waste, all furnishes having the same effectiveness of furnish; cal culated values are shown in the follo:?ing table: CTD001024 Per cent Fiber Blend ib.3i 16.01 15.71 15*42 15.12 Per cent Pulverized Waste 0 5 10 15 20 Effectiveness of Furnish 1377 1377 1377 1377 1377 Calculated Density of Pipe Lbs./Cu.In. 0.0040 0.0628 0.0615 0.0602 0.0590 Calculated Bursting Pro3S.P6" Class 150 504 772 741 710 680 It is evident from this table t'c at the net effect of adding Pulveriz cd Waste and retaining a cons tent effectiveness of furnish is to reduce density and bursting pressure. If Pulverised Noisto :ls added to replace cement and silica, the effectiveness of furnilsh is increased but despite this. the calculated bursting pressure sti.11 falls off with increased percentages of Pulverized Waste as shown in the following table: Per cent Per cent Fiber Pulverized Blend Waste 15.94 0 15.94 5 15.94 10 15.94 15 15.94 20 Effectiveness of Furnish 1346 1371 .1396 1421 1446 Calculated Density of Pipe Lbs./Cu.In. 0.0640 0.0628 O.C615 0.0602 0.0590 Calculated Bursting Press.PSI 6" Class 130 7S3 768 749 730 709 From the preceding two tables. It is evident that the per cent fiber blend must be Increased with increasing amounts of Pulverised Waste If strength Is to be maintained. This Is 'shown In the follow ing table which gives the per cent fiber blend required with varying amounts of Pulverized Waste to obtain a calculated bursting pressure for 6 inch. Class 150 pipe of 750 pounds per*square inch. Per cent Per cent Fiber Pulverized Blend Waste 15.04 0 15.48 15.96 5 10 16.49 17.08 15 20 Effectiveness of Furnish 1270 1332 1398 1468 1542 Calculated Density of Pipe Lbs. /Cu.In. 0.0640 0.0628 0.0615 0.0602 0.0590 Calculat Bursting ?r 6" Clas3 750 750 750 750 750 On the attached sheet are shox?n several graphs which are of Interest. Graph Ho. 1 shows how the density drops as the per cent Pulverized Waste is increased. Graph Ho. 2 shows how much the fiber has to be increased a3 the per cent Pulverized Waste is increased in order to maintain a bursting pressure of 750 pounds per square inch. Graph No. 3 shows the furnish cost per pound to retain a bursting pressure of 750 pounds per square inch. Two curves are shown: one for Pulverized Waste at 0.0050 per pound and one for Pulverized Waste at no value. Plant No. 6 has set up Pulverized Waste at no value but V CTD001025 -5- this la obviously fictitious; Kr. Hedrick estimates a falx* value as 0.005 per pound. While coat of furnish per pound increases with increasing percentages of Pulverized Waste, the density decreases; the net effect is plotted on Crarh Uo'. 4 v;hich shows the cost of furnish per foot of 6 inch. Class 150 pipe. With co3t of Pulverised With- the coot of Pulverized Waste at 0.005 per pound which Is believed very slightly with increasing amounts of Pulverised Waste up to about five or six per cent and thereafter remains essentially constant. Thus, above about five or 3lx per cent, it is not an economy to use Pulverized Waste at Santa Clara; it is actually dotz mental because of the lower density and the likelihood of receiving complaints on weepage and/or leakage. The same conclusion applies to St. Louis which also uses an autoclave furnish. It is interesting to speculate whether one of the reasons that Santa Clara has been able to use con siderably cheaper furnishes than St. Louis is due to the use of about six per cent Pulverized Waste at Santa Clara and about twice this amount at St. Loui3. Plant 8 can probably afford to use slightly more Pulverised Waste, say up to ten per cent, because of the inherent higher density of the normal cure furnish. The use of some Pulverised Waste in the furnish is desirable, not only to prevent the accumulation of scrap but also because it probably aids In formation and filtration. Recommendations; Because the use of Pulverized Waste in the furnish results in lower density pipe, because low density pipe are a potential source of difficulty due to weepage and/or leakage, and because it costs little if any more to make higher density pipe by minimizing the use of Pulverised Waste, it is recommended that the use of Pulverized Waste be limited to a maximum of six-per cent at'St. Louis and Santa Clara and a maximum of ten per cent at Ambler. RLL:ec Att. CTD001026 APPENDIX In Mg work on fiber evaluation, Mr. J. A. Malone has developed an equation: S = 33.4 + 0.149 (RF + 5W). where S <= breaking load of the pressed cake used for determining the relative strength of the fiber, pounds. P. a relative strength of the fib r. J? * per cent fiber in the furnish. W <* per cent Pulverised Waste in the furnleh. Assume that the bursting pressure of n $ inch. Class 150 pipe ia proportional to the strength of the furnish and therefore is proportional to tho breaking load of Mr. Malone's pressed cake. B = aS where B = bursting pressure of a 6 inch, Clasa 150 pipe, PSI. a 3 constant substituting, B a(33.4 + 0.149 RF + 0.745 W). lie knew that strength is proportional to the square of the density and we have also estimated that the density of pipe made ) at Santa Clara without Pulverised Waste would be about 0.064 pounds per cubic inch. A factor correcting for density (D/0.064)2 can thus be Introduced. B = a(33-4 + 0.149 RF + 0.745 W)(D/0.064)2 where D is the density of pipe in pounds per cubic inch. Prom several experimental runs v;e have estimated: that one per cent Pulverized Waste reduces the density by 0.00025 pounds per* cubic inch. If pipe made without waste is 0.064 pounds per cubic inch, D 0.064 - 0.00025 W. Substituting for D. B a(33.4+0.149 RF+0.745 W)(0,064 -0.00025 W)2/(0.064)2 Simplifying, B a(33-4+0.l49 RF+0.745 W)(l - 0.004 W)2 The data for five experimental runs of six inch. Class 150 pipe was inserted in the above formula and five values of "a" v?ere determined: 3.43, 3.43, 3-04, 3.35, and 3.45. The value of 3-04 was discarded and the remaining four values averaged to gii-'e a 3.41. Substituting and simplifying we get the equation: B = (115 + 0.5 RF + 2.5 W)(l - 0.004 W)2 This is the formula which was used to calculate the data in the tables In the body of the report. ^ CTD001027 J CTD001028 Mfl CTD001029