Document oDZjNxpNxMpQbGBMRxEKpNde8

THE DOW CHEMICAL COMPANY MIDLAND DIVISION July 28, 1969 -*J. M. Scovlc cc: R. G. Carlson D. D. Deline A. C. Wilcox INSULATION MATERIALS The Productivity Committee has reviewed your letter of July 24 with the attachments that outlined some of the economic considerations comparing Aircell asbestos insulation with Fiberglas. It is clear that we have not only a significant safety advantage with Fiberglas but an economic advantage as well. We strongly support your pursuing the necessary conmunication program within the Mainten ance organization that you suggest and taking positive action steps to discontinue the use, wherever possible, of asbestos Insulation. DOW 00098 ST0000302 !%o\*2 MIDLAND July 24, 1969 THE DOW CHEMICAL COMPANY ST0000303 J. M. Scovie Manager of Services 47 Building INSULATION HAZARDS AND MATERIAL REVIEW (ECONOMIC PHASE) The prime objective in developing our program on insulation hazards and materials has been to correct a potential safety hazard we may have. Attached you will find an economic analysis. This analysis is in much greater depth than we intend to present in our communications program as part of the formal agenda. This economic information has been gathered mainly for background information and will be used to answer economic questions which I am sure will arise. I might at this point say a few words about the attached exhibits. Exhibit lisa letter written by Roy Anderson which is intended to be mailed out to the production representatives after they have attended our communications meeting. The objective of this letter is to reinforce our opinions on the merits of the various insulation materials. Exhibit II is a simplified, straightforward, hypothetical cost comparison. Exhibit in is the backup data used to develop the figures in Exhibit II. Wc have a factor in the economics of comparing insulating materials which we have previously not examined closely which is the thermal conductivity coefficient. The k factor for Aircell is .61 while the k factor for Fiberglas is .29. Over the years Aircell insulation has been grossly misapplied. The top temperature limit for Aircell is 200F. In order to have a working system we have found that additional steps have been taken to make up for this thermal conductivity coefficient deficiency. One that is commonly used is the wrapping of the pipe and tracer with aluminum foil prior to installing the Aircell. A second method which is commonly used is applying Thermon heat transfer cement on the tracer to more evenly distribute the heat. By using the proper insulation such as Fiberglas. the need for . :ese extra steps could be eliminated. The cost of these extra steps ce: -inly must be taken into consideration when comparing Fiberglas and Airceil insulation. DOW 00099 J. M. Scovie -2 July 24, 1969 Exhibit IV simply state? the volume of Alrcell insulation used. The latest figures available are for the year 1967. However, the insulation material costs are the current costs. It is undetermined at this time whether an increase in the volume of purchase of fiberglas would qualify Dow for a lower per unit cost. Exhibit V, which is an analysis by Roy Anderson, states the steam cost penalty we pay for under insulating when Aircell insulation is used without a backup of either aluminum foil or thermon* Our estimates do not include the additional cost of the safety precautions we will have to take to protect our people against the asbestos hazards connected with Aircell. We estimate an additional 20 minutes per day will be diverted away from the productive portion of a job into the safety portion of a job due to the use of respirators. This amounts to an additional cost of roughly $58, 000 on an annual basis. The purchase of the respirators themselves and the replacement cartridges will add another $4, 000 annually. Shower time will not be automatic when insulators install Fiberglas. The Foreman on the job will use his discretion with the insulators as he does with the other craftsmen as to when shower time should be recommended. I am sure that the cost of shower time will diminish as Fiberglas becomes a more accepted insulation material. Following is a combination of the data shown in Exhibits II and V reflecting the most extreme conditions. The example was to insulate 200 feet of traced pipe: Fiberglas insulated Aircell insulated One shot savings on insulation costs Steam cost increased $23 per year Return on investment 42.6% $506 $442 $ 54 1 believe first and foremost from a safety standpoint that it is imperative that we change our insulation practices. I believe from an economic stand point the overwhelming use of Fiberglas insulation throughout the country would certainly indicate an economic benefit will be gained from using it. I would like at this point to express my appreciation for the assistance that Larry Warren and Roy Anderson gave in developing the attached data. I think these are two professionals that we can truly be proud to have within our organization. ST000030U DOW OOlOO J. M. Scovic - 3- July 24, 1969 Please feel free to contact roe on any further questions you may have. T. J. Madden Maintenance Manager Agricultural Chemicals Production Organic Chemicals Production 222 Building Phone 6-2225 TJMrrb Enc. ST0000305 DOW 00101 INSULATION ECONOMIC ANALYSIS AIRCELL VS. FEBERGLAS EXHIBIT I EXHIBIT II EXHIBIT III EXHIBIT IV EXHIBIT V Roy Anderson's letter to Plant Supervision on insulation alternates and applications Summary of comparative insulation costs on a hypothetical job Detailed labor and material cost comparisons Aircell insulation usage and material costs of Aircell vs. Fiberglas Theoretical heat loss comparison between Aircell and Fiberglas insulation ST0000306 DOW 00102 MIDLAND July 24, 1969 EXHIBIT 1 Page 1 of 2 THE DOW CHEMICAL COMPANY ST0000307 INSULATING MATERIALS AND ALTERNATES We are principally concerned in this discussion with materials which may be substituted for some of our existing asbestos*containing in sulation and how this will affect us economically. The use of Aircell pipe insulation should be eliminated from the plant. It should never be used in any application over 200F. and then for personnel protection only. It has a K factor of . 61 as compared to .29 for Fiberglas. Fiberglas is about 25% more expensive to purchase; however, if aluminum foil is used with Aircell, as is the case many times, it is questionable whether one is more expensive than the other. (See table of estimated costs attached.) Temperature wise, Fiberglas is recommended up to 400F. It is available either plain or with a number of factory applied jackets, some of which are self-sealing. Ordinarily, we would cover the plain Fiberglas insulation with the same JM paper that is now Used over Aircell.- It is necessary to wire the paper onto Fiberglas inasmuch as staples will not hold. This procedure makes the process slightly more time consuming than with staples. A completely dry piping system can be made up by using wedges of Fiberglas blanket for ells and fittings and covering these with preformed fittings of PVC. A waterproof tape can be used to seal the joints. In the temperature range of 400 to 1200F., calcium-silicate is still the standard insulating material. As a substitute, we are presently making a survey of Careytemp 1500. This is an expanded silicon (perlite) material with a temperature range up to 150OF. It does not absorb water and has a very low chloride content. At the present time it con tains about 6% asbestos; however, in the near future it may be available in an asbestos-free form. The K factor is almost identical to calciumsilicate. Another alternate material for temperatures up to 800F. is cellular glass. This material is more expensive than calcium-silicate and should be used only where its special properties merit the extra cost. It is more dense than calcium-silicate and non-absorbent. This property makes it especially valuable where there is danger of autoignition. It is ideal for dual temperature vessels or pipelines. The material is easily worn away by abrasion and for this reason tank heads should be adequately protected. Glass cloth imbedded in epoxy resin is excellent for this purpose. ^ EXHIBIT 1 Page 2 of 2 If The material is available in preformed sections for both pipes and tanks. The K factor is very similar to calcium-silicate. The Dow Chemical Company has only recently entered this field with a material called Ceramic Foam. If you have any questions or want further information on insulation, please feel free to contact me. Roy Anderson Maintenance Engineer ACP L OCP Maintenance 222 Building Phone 6-4456 rb DOW 00104 ST0000308 HYPOTHETICAL COVERING JOB ST0000309 EXHIBIT II DOW 0 0 1 0 5 Aircell Labor & Material Aircell with aluminum foil Aircell with thermoh Fiberglas $506 2" product pipe with steam tracing using 2-1/2" I. D. insulation. Labor rate 0.00 $/hr. J. M. Paper weather proofing INSULATING A 2" PIPE SYSTEM PER FOOT EXHIBIT HI AIRCELL Material: (Aircell (J.M. Paper Labor: (Aircell (J'.M. Paper A ire ell total cost: .29 per ft. .30 per ft. . 59 per ft. 1.50 per ft. . 12 per ft. 1.62 pmer ft. 2.21 per ft. ST00003I 0 AIRCELL WITH ALUMINUM FOIL Material: (Aircell (J. M. Paper (Aluminum foil Labor: (Aircell (J. M. Paper (Aluminum foil AIRCELL WITH THERMON Aircell with aluminum foil total cost: Material: (Aircell (J. M. Paper (Thermon Labor: (Aircell (J. M. Paper (Thermon Aircell with thermon total cost: . 29 per ft. . 30 per ft. . 09 per ft. . 68 per ft. 1. SO per ft. . 12 per ft. . 03 per ft. 1.65 per ft. 2. 33 per ft. . 29 per ft. . 30 per ft. . 40 per ft. . 99 per ft. 1. 50 per ft. . 12 per ft. . 26 per ft. 1. 88 per ft. 2.87 per ft. Material: (Fiberglas (J. M. Paper Labor: (Fiberglas (J.M. Paper* Fiberglas total cost: *J. M. Paper wired on Fiberglas vs. stapled on Aircell T% M . 43 per ft. . 30 per ft. . 73 per ft. 1. 50 per ft. . 30 per ft. 1. 80 per ft. 2. 53 per ft. DOW 00106 exhibit IV COMPARATIVE INSULATION MATERIAL COSTS Size (inches) 1/2 3/4 1 1-1/4 1-1/2 2 2-1/2 3 3-1/2 4 5 6 8 4-1/2 12 7 1967 Usage of Aircell (feet) 400 1500 4000 6000 9000 11000 20000 6000 3500 3000 2500 7000 4000 3000 1500 1968 Prices (per ft.) Aireell _________Fiberglaa .18 $ .29 .19 .31 .22 .34 .24 - ,26 .40 .29 .43 .32 .46 .36 .50 .40 .55 .48 .65 .56 m .64 - .88 1.46 .52 .69 1.48 4 1.18 82,400* of Aircell used in 1967 ST0000311 TJM 7-24-69 qO\07 OOU EXHIBIT V THEORETICAL HEAT LOSS COMPARISON BETWEEN AIRCELL L FIBERGLAS INSULATION Conditions: Assume: Equation: 3/8 inch tracer with 150# steam on a 2 inch product line 200 feet long. Insulation thickness 3/4 inch That heat from 1/2 of the area of the tracer is absorbed by the product and heat from the other half goes to ambient (70F.) thru the insulation. Q * -^At- where: Q 8 BTU/hr. heat loss k 8 Thermal conductivity A 8 Area of pipe surface At s Temperature difference between tracer (370F.l and surfaces being heated. Ax 8 Insulation thickness in inches BTU Hr. ST0000312 At a product temperature of 150F. the heat loss difference between Aircell and Fiberglas is about 4500 BTU/hr.per 200 feet 2 inch line. This represents 3. 75 lbs. of steam/hr. or $23 per year. Roy Anderson AfP At nr'P Maintenance DOU 00108