Document jBD9R1nnbm69z8NnmbgXnorDR

Section A Transformer Askarel Introduction The term askarel as defined'by IEEE, ASTM and the National Electrical Code generally describes a broad class of non flammable synthetic chlorinated hydrocarbon insulating liquids widely used in transformers, reactors, and accessory equipment operated at power frequencies. Askarels of various compositional types are in use (for;the general properties and-types see ASTM D-2283). Under arcing conditions the gases produced, while consisting of predominantly non combus tible hydrogen chloride, can contain varying amounts of com- iistible gases depending upon the askarel type. r Thl3 manual describes the operating characteristica of trans former askarel liquid Insulation and how It differs from mineral oil. Appropriate handling and disposal procedures for both scrap-askare.l. liquid and impregnated solid mate rials are given in accordance with the guideline recommended by the American National Standards Institute. The information is based on facts gathered by Monsanto over ^0 years as producer of askarel* plus knowledge gained from the experience of transformer manufacturers and users. This guide outlines the very simple maintenance required for askarel fluid in "modern'' transformers and offers sugges- triSnSufor sealing and maintaining a3karel in old units. By-following this guide., users will obtain maximum service fSBSKS NPC00035415 PLAINTIFFS \ i EXHIBIT 1_|038_ 905077 '9 a -2- from askarel Insulation with a reasonable minimum of maintenance. If questions arise relating to the design ing and. building of transformers, these should be referred to regular transformer suppliers. Monsanto gratefully acknowledges the assistance, guidance, . and the contributions of certain data by the following: , v Edward L. Raab -- - General Electric Dr. T. K. Sloat --Westinghouse Electric Til. History of Trade Name Types "Askarel'' Is the generic name for the non-combustible St'liquid insulation and coolant first used by General Electric Company in'1932 for"their'Pyrahol brand name fire-resistant Hrans forrmerrss-.. ' -t- 1' Other brand names used by electrical manufacturers to desig nate transformer asicarels used in their products include: Asbestol, Chlorextol, Inerteen, No-Plamol, Saf-T-Kuhl. Whatever the trademarked brand, the askarel contains chlorinated biphenyl .. one of the best liquid insulations developed by science. This inert mate rial is chemically stable, fire-resistant, heat stable, non- corrosive, and has high dielectric strength under the opera ting conditions encountered in transformers. .'vtiswe. NC000354I6 -*JJ'Wfc^WBWnfIHT.IHIJ. 905078 -3- p In addition to manufacturing Aroclor (chlorinated biphenyl), Monsanto also mixes this dielectric fluid with chlorobenzenes to produce the presently used Inerteen and Pyranol blends de scribed in Table I. Table I The Composition of Transformer Askarels Type D Method ASTM Type Dc 2283 Type P -. Trade Names Inerteen 54201KA Inerte.cn 54201CM Pyranol.A13B3B2 Inerteen 70-30 Inerteen 100-42 ^Ingredients (% by wfe.) Aroclor 1254, pentachlorobiphenyl 70 ^Aroclor 1242, trichlorobiphenyl - 100 trichlorobenzene 30 - irt^tri-tetrachlorobenzene.w* . propene oxide scavenger 0.18 to 0,22 0 .18 to 0.22 MjfKptTdiepoxide scavenger 45 55 0 . 1 1 5 to 0.135 M ASTM Method D 2283, titled Chlorinated Aromatic Hydrocarbons / '. '/ (Askarels) For Transformers, also lists the composition of all transformer askarels used at various times since 1932. Monsanto manufactures similar transformer askarel fluids in England where the trade name Pyroc lor Is used.; III. Interchangeability In general all transformer askarels are interchangeable. How ever, it is suggested that the transformer manufacturer be consulted prior to mixing in significant proportions or total substitution. r . NPC00035417 905079 -4IV. Official Transformer Askarel Shipping Specifications/ The official shipping specifications for the three modern transformer askarel fluids are 3hown in Table II. NPC00035418 905080 U1 IJLCJ.Cl JL <4.J. ca' ^ ~ -- NPC00035419 Specification Properties Transformer Pyranol A13B3B-2 ASTM D2283 Type F Westinghouse Transformer IornerItneeerntee5n42J0O1K- 3A0 ASTM D2283 Type D Westinghouse Trans former Inerteen 54201CM or Inerteen 100-* ASTM D2283 Type : Color, AFHA I5O max. 150 max. 60 max ; Condition Viator content, ppm (ASTM D1533-60) Acidity, mg KOH/g (ASTM D974-55) Clear 30 max. 0.014 max. Clear 30 max. 0.014 max. Clear . , 35 max. 0.01 max. ' Dielectric Strength,25"C,0.1 in. gap 35 KV, min. 35 KV, min. 35 KV, min. 7 (ASTM 0377-^9) Dielectric Constant,100C, 60 Hz 4.2 to 4.6 4.2 to 4.5 4.7 to 4.9 (ASTM D924-49) Volume Resistivity, 100C, 500 volts DC 0.1 inch gap, 109 ohm-cm (ASTM DI169) Inorganic chlorides, ppm (ASTM DI82I and 100 0.10 max. 100 0.10 max. 100 0.05 max. G.E. Method E4c41B) Refractive index, 25 C (ASTM Dl807) Viscosity at 3 7 .8C (ASTM D83-56) .I.6060 to 1.6070 , :39;to 43 1 .6 15 3 to 1.6173 1.6240 to 1.6260 56 to 61 82 to 92 Saybolt Universal Seconds ir\ i Pour Point "C (ASTM D-97-57) Specific gravity 25/ 1 5 .5C (ASTM Dl8l0) Burr, point (ASTM D92) Distillation range (ASTM D20-56) corrected for stem and barometric pressure ?-- 42 or lower 1.515 to 1.525 None to boiling 1st drop 210C min. %3555%^ >i 224900 to to 270 330 _6556 t355 to 380 -30 or lower 1 .5 1 8 to 1.528 -17 or lower 1.3 8 1 to I.392 None to boiling None to boiling 1st 35^ drop 200C min, below 270C 9100% 325C min. 380 max. 90^ 379 to 394 f.95*:-375 to 395 Fixed chlorine Corrosion test 458.5 .5J6 55.6# min. 430.5# After heating with aluminum for 6 hrs. at 200 to 220C, :;lwtehieghatlumIinnsupmectmuisotn not and be corroded the askarcl on either visual or should meet the fol Color, APRA Acidity, rg KOH/g Inorganic chlorides ppm Condition Scavenger content '}l 2o0w0inmgax.specifications: 200 max. -0.014 max. 0.014 max. io.L5 max. 2.0 max. :i5 to 0.135# Clear 0.18 to 0.22# oxide phenoxy propine 7 i1(Cy,P$ l S I( /y 0.18 to 0.22% pbhcxy oropene Typical Properties Coefficient of Thermal Expansion oxide 0.0007 oxide 0.00068 .(ASTM D1903), cm2/cm2/ ^ f Arc formed gases .. -6 Footnote 1 Askarcls of various compositional types are used. Under arcing conditions the gases produced,- while consisting predominantly of non-combustible hydrogen chloride, can include varying amounts of combustible gases depending upon the askarel type. Insulation systems incorporating these askarcls and cclluloslc or other organic materials may, when arced, produce gaseous mixtures''which are moder ately flammable. As a precaution, such gases should be removed from the askarel by bubbling dry nitrogen through the askarel and flushing the gas space with dry nitrogen ^before any work Is performed-on the apparatus. NPC00035420 905082 -7- IV. Ordering Instructions These transformer fluids must be ordered through the manufacturers of askarel transformers rind not Monsanto. The transformer name plate indicates the transformer maker and usually gives sufficient data to identify the specific a3karel fluid used. V. Stability Askarel liquid insulation is highly pure, fire-resistant liquid made under close chemical control to meet the exacting specifications as shown in Table II. It does 'not vary in composition like the commercial range of mineral oils. Askarel insulation must never be mixed with mineral oil. Over two percent of mineral oil by volume in askarel be gins to lower its fire resistance. Askarel does not deteriorate when exposed to air, heat, hot metal; it does not break down over long use to form conducting or corrosive chemicals; it does not oxidize or sludge. Askarel will remain perfectly stable year after year unless broken down by severe electrical discharge. NPC00035421 905083 -8In modern transformers, the only real "enemy" of askarel Is contamination by water. Keeping askarel v/ater-free will insure long-time service* Askarel is heavier than water. If water gets into askarel insulation, .only a .tiny, amount (125 ppm) dissolves -- the. rest floats on top. Askarel is very insoluble in water/ only about 200 parts per billion of askarel dissolve in water, at normal temperatures. Precautions Vfhen Handling Drums, Tankcars and Opening Transformers The American Institute of Electrical and Electronic Engineers Guide No. 76, Dec., 1958 has been revised to give more deu *tail^d instructions and guidance For Acceptance and Main- ' tenancs of Transformer Askarel In Equipment* The following are significant precautions; A. Keep Dry During Handling: In handling, storing, sampling, inspecting askarel -and in operating askarel transformers --take every pre caution to guard the askarel insulation from exposure to high humidity and moisture contamination. Keep 5, 30 or 55 gallon drums of askarel dry; lay stored drums on their sides with the bung at the highest point from floor to keep water off the drum head (which can be sucked into the askarel by the drum "breathing"). This precaution is not necessary when ,,drums are stored Indoors, "T. which is the preferred wav of storing. NPC00035422 905084 -9To avoid leakage the drums used for askarel are of heavy construction, -Sixteen gauge metal is, used, with special rim seal and bung'construction* The drums should be, drained a3 completely as possible and then flushed twice with kerosene type solvent to re move all of the askarel. The solvent washings must be incinerated at high temperatures, e.g. 2000P to destroy the polychlorinated biphenyls (PCDs), Tank cars used to transport askarels are in exclusive service and not used interchangeably for other products. e unloaded through the top (dome fitting) either by pumping or with controlled pressure using dry air or dry nitrogen. If nitrogen has been used for un jlv/ xo iiece3sary to advise the shipper so that when the car returns the nitrogen can be replaced with dry air before any one may enter the car If the car is. to be unloaded by pumping it will be.neces sary to use a dryer on the air intake line to remove moisture. All tank cars are fitted with steam coil3, which are available for unloading under extreme conditions of low temperature. Convenient handling and pumping temperatures and the re lated' approximate viscosity ranges arc given in Table III. NPC00035 4 905085 -10- Table III Produc1: Unloading, Handling and Pumping Tem perature C Approximate Viscosity SUS Pyranol A13B.1D-2 15-40 . ' 100-40 Incrteen 54201KA 1 . 20-55 100-40 Incrtecn 54201CM 35-75 100-40 B. Use Ordinary Personal Precautions: Transformer askarel has been made, handled, and used for over 40 years without causing toxic or other ill effects. It can be handled with only minor precau tions. If accidentally spilled on hands, no serious skin irritation will occur. However, liquid askarel */*>' _ has a solvent action (similar to paint thinner) on the fats and oils of the skin and prolonged contact may lead to drying and chapping of the skin. In case of contact, wash off the skin with soap and / water; remove and dry clean saturated clothing. Clean up spills with rags, sawdust or absorbent clay. Eye contact may result in painful irritation but no per manent damage to tissues. If askarel gets in the eyes, flush with large amounts of water. 3 with all eye \ first aid, refer to a physician. To relieve irritation, \ i physicians have used a 1$3 Fontocaine as well as opthal- mic cortisone acetate solution, or castor oil. Hi : = NPC00035424 905086 -iiInfrequent exposure to askarel vapors will not cause ill effects. However, prolonged exposure to high vapor concentrations should be avoided. If hot askarel must be handled in a closed or confined area, provide the area with ordinary exhaust ventilation -- or' wear an organic cartridge respirator approved by the U. 3. Bureau of Mines. Precautions On Opening an Askarel Transformer: Askarels of various compositional types are used. Under arcing conditions the gases produced, while consisting of predominantly non-combustible hydrogen chloride can yield varying amounts of combustible gases depending upon the askarel type. Insulation systems incorporating these askarels and cellulcsic or other organic materials may, when arced, produce gaseous mixtures which are moderately flammable. As a precaution, such gases should be removed from the askarel by bubbling dry nitrogen through the askarel and flushing the gas space with dry nitrogen before any work is performed on the apparatus. NPC00G35425 905087 -12VII. Avoid Environmental Pollution Transformer asicarels contain polychlorinated biphenyls (PCBs) which have been used In the United States and elsewhere over the past 40 years, for many industrial and consumer applications. During the past several years evidence has accumulated to indicate that PCDs are widely dispersed throughout the environment and that they can have adverse ecological and toxicological ef fects. The United States Governments Interdepartmental Task Force on PCBs, Com-72-104l9> In their March 20, 1972 report titled,"Polychlorinated Biphenyls and the Envlronment" recommended restricting PCBs to use in capacitors and transformers. This report is distributed by the National Technical In formation Service, tf.S, Department of Commerce, Springfield, Virginia 22151. A document titled,"Guidelines For Handling; and Disposal of Capacltor and Transformer Grade Askarels. Containing Polychlorinated Biphenyls," has been prepared by the American National Standards Institute, Committee C107, 155 East 44th Street, New York, N.Y. 10017. JJPCa0O35426 905088 -13- The scope, objectives and the composition of this committee are: ANSI Committee C107 Scope : Procedures and guides for 3afe use mainten ance and disposal of askardl and askarel-soaked materials used in electrical equipment. Objectives : 1. Source of technical information and advice for Federal, State, local authorities ancl all others concerned. 2. Encourage development of suitable disposal facilities and keep all concerned informed. 3. Serve as the advisory group for United'States participation in international organizations: CEE, IEC, CIGRE. Composition : Organization;active or represented by this ANSI committee include: National Electrical Manufac turers Association, Electronic Industries Assoc iation, Institute of Electrical and Electronic Engineers, American Society For Testing and Mate rials; Electric Light and Power; Environmental Protection Agency; Office of Environmental Affairs; tm sr. / NPC0003 54 27 905089 ' -U-. General Services Administration ; National Bureau of Standards; Dept, of the Army; Rural Electrification Administration; Dlv. of Environ mental Research, TVA; American Public Power Assoc., Water Pollution Control Federation; Food and Drug Administration; National Fire Protection Assoc.; Underwriters Laboratories; and several sections of the TJ.S. Department of Interior The following are pertinent excerpts taken from the ANSI Guidelines for askarel transformers: 1. Labeling Askarel Transformers I*!-" All new askarel transformers sh#ould be labeled: Caution The Insulating Liquid in This Transformer Contains Polychlorinated Biphenyls (PCBs). Care Should Be Taken To Prevent Entry Into The Environment. In Casa Of. Malfunction Or Leaks, Consult The Instruc tion Manual Or The Manufacturer.. The transformer manufacturer should make similar warning labels available for use on previously in stalled transformers.... 2. Disposal of liquid and Solid Wastes Disposal of askarel fluid and askarel-soaked mate rials must be accomplished by means in which there is no significant release of askarel to the environ ment. At present.* disposal is accomplished by care--- fully controlled high temperature Incineration of & 7 NPC000354 28 905090 -l6- ' earth in cartridges or bags when replaced should be allowed to thoroughly drain over drip pans to remove as much liquid askarel as possible. The cartridge units, of steel mesh construction should be placed in the "Steel Contaminated with Askarel" container for disposition. Cloth bags filled with Puller'3 earth should be placed in the "Scrap Burnable A3karel Waste" container for disposition. Teardown of Transformers for Repair or Scrap a. Drain all askarel from the unit either into a holding tank for reuse or into the drum labeled "Scrap Askarel" for disposition, then allow suf ficient time for all the askarel to drain from the core and coils. b. Remove the core and coil assembly from the trans former and place it on the floor. Sufficient absorbent material should be placed on the floor to absorb any askarel fluid that still drips from the transformer. . . c. Place all materials in the appropriate salvage containers during the dismantling for later dis position. d. All used materials, Including rags, sawdust, tape, etc., regardless of quantity, should be put into the appropriate containers for disposition. NPC00035430 905092 liquids, and soaked software; and by controlled dry land-fill burial of apparatus and other hardware from which askarel has been previously drained and washed. Present knowledge indicates that proper incineration should involve a suitable balance between dwell time and temperature in the incinerator plus oxygen availability and finally suitable scrubbers to re move HC1 formed; eg. (l) two-3econd dwell time at 2000F and 3# excess oxygen in stack gas; (2) 1-1-|second dwell time at 2700P and,2-5$ excess oxygen in stack gas. The ANSI Guide lists the locations of facilities that conform with the above requirements. Monsanto has such an incinerator at the W. G. Krummrlch Plant, Dept. a -246, Sauget, Illinois, where scrap askarel liquid is received for disposal at 3 cents per pound charge. Por disposal of solid scrap a, controlled dry land-fill or deep-well disposal can be used where permitted by Federal, State and local regulations. 3. Conditioning of New or Recycled Askarel Conditioning of new askarel or recycled askarel re quires Puller's earth treatment. The spent Fuller's ssm - NPC00035429 905091 18-' Mr. Frank M. Clark, who invented transformer askarels at the General Electric Company in the early 1930s, made the highly pertinent comment based on his many years of experience s*ith G.E. Pyranol (askarel type) transformers that -- "The important thing Is to keep them dry -- otherwise leave them alone . ' These words of Wisdom became especially applicable in more recent years when welding shut rather than gas keting became the main method of sealing askarel trans formers. These units are sold with the understanding that the liquid is In a normally hermetically closed: system. IX. General Characteristics of Transformer Askarel Fluid \ Appreciation of the following characteristics, as given in the IEEE Guide, leads to understanding the reasons .'for selecting dielectric breakdown voltage and moisture as the prime practical tests to Judge the quality of transformer askarel fluid. Also due to these characteristics the power factor of transformer askarel wiJl be normally much higher than the corresponding values for mineral oil. NPC000354 32 905094 -17- 5,, Transformer Disposal The ultimate disposal of an askarel-fllled transformer may be accomplished in either of two ways: a. Complete drainage and dismantling with the proper disposal of the askarel liquid and askarel-soaked components a3 described above. b. Disposition of askarel transformers by means of junk or scrap dealers should be avoided unless a transformer is .first drained, followed by soaking of the interior with a suitable solvent, 3uch as kerosene. Accumulated liquids and washings are to be disposed of as described earlier. VIII. Expected Service Life Properly designed and installed askarel transformers are expected to give trouble-free service for a minimum of 30 years. Since their introduction in 1932 > the manu facturers report finding the over-ail failure rate to be less than 0.5^ for all units under test and service con ditions. The Edison Electric Institute's report (19551958) on their member utilities publishes the failure rate for askarel transformers as 0.13 per hundred banks per year. NPC00035431 905093 -19In comparison to mineral insulating oil, .askarel is a relati vely polar material; i.e., itsmolecules are dipoles, free to rotate around their axes and responsive to orientation by elec trical forces. Askarel also exhibits a much higher dielectric constant and capacitance than Insulating oil, and these dif ferences must be kept in mind when interpreting electrical test data. Because it is relatively polar, and possesses high solvency S ; power, askarel is much more electrically sensitive than mineral oil to traces of extraneous soluble polar materials, and ccnsejuently the choice of constructional materials destined for u3e n'iaslcarel is very critical. This sensitivity is reflected in : . the power factor and resistivity (specific resistance) of the askarel. It is important to note that, with the exception of water, the dielectric breakdown voltage of askarel is not generally ad versely affected by many of the soluble polar materials to which its power factor and resistivity (specific resistance) are so sensitive. In fact, the dielectric breakdown voltage of askarel is somewhat greater than that of insulating oil. Therefore, who values assigned these dielectric fluids In newly supplied transformers are 30 KV min. and 26 KV min., respectively. NPC 000354 33 905095 -20- As with insulating oil, askarel must be kept dry. It can pick up moisture from exposure to humid atmosphere. Under similar conditions of exposure, askarel can pick up nearly twice as much moisture when measured on a parts per million weight basis. X. 'Sampling Transformer Askarel Fluid The following precautions about sampling are quoted from the IEEE Guide. Representative samples, whether of the complete contents or only parts thereof, are extremely important from the standpoint of evaluation of the quality of the product sampled. Obviously careless sampling procedure or con tamination in the sampling equipment will result' In'll ' sample that is not truly representative. This generally leads to erroneous conclusions concerning quality and incurs less of time, effort, and expense involved in se curing, transporting, and testing the sample. It is strongly recommended that all of the procedures and pre cautions outlined in the latest revision of ASTM D 923 (Sampling Electrical Insulating Liquids) be followed. Because of the high specific gravity (relative density) of askarel (greatei than 1), water and some other impu rities are most likely to be found at or near the surface. The top sample, therefore, is considered to represent Hi~worst condition. U.PCQD035434 905096 -21- Evaluation of Askarel Received in New Equipment Some users of askarel equipment find it desirable to make "as received tests'1 on all equipment. It is quite common to use the dielectric breakdown voltage test and visual appearance as the most significant tests. If suitable equipment and trained personnel are available additional information may be obtained from the power factor, color, and moisture content tests/ In.sampling askarel contained in apparatus extreme care must be exercised in order to obtain a representative sample* ASTM Method D 923 should be followed. New equipment with askarel exhibiting the following charac teristics i3 considered acceptable: Dielectric Breakdown Voltage Color Condition - Visual Water Content Power Factor at 25C ASTM Methods 30 kV min. D 877 300 max, (Straw color) D 2129 Clear D 1702 35 ppm max, *; D 1533 D 92^4, D 150 The power factor of askarel taken from new transformers, reactors and accessory equip ment can reflect the presence of moisture, . dissolved polar compounds, or other contami nants and may vary with the type of equip ment from which the sample was taken due to the different ratios of liquid-to-solid in sulation and to the high solvency power of the askarel. Given an acceptable water con tent and dielectric breakdown voltage of the askarel as indicated above, a high power factor seldom impairs the serviceability of _ the askarel within rather broad limits and is indicative of the degree of extraneous soluble polar materials present. `RE* NPC00035435 905097 -24- XIII, Turbidity ,.may be the visual sign of undlssolved water, or may indicate dirt. Cloudiness may also result from cold precipitation of tin tetraphenyl "seavenger" that was used in the earlier Pyranols. Tills scavenger begins to come out of solution around 15?. above zero* To redissolve it requires heating to 150-200P and agita tion. High dielectric breakdown voltage will quickly indicate that any turbidity present is not moisture; that the insulating.efficiency of the askarel is still excellent. However, if the dielectric strength is below 26 KV, moisture should be determined, using the Karl Fischer method (ASTM D1533-60). The dielectric breakdown voltage test for askarel serves primarily as an indicator for moisture. It is by far the most important maintenance test for transformer askarel. XIV. Check Points for Maintaining Askarel Insulation A. General Considerations: Modern askarel transformers with welded construction or siliccne or Viton gaskets for hand hole-cover, switch and terminal compartment covers, v/ith properly constructed bushings require little or no maintenance. -- IITl-Viith properly constructed transformers, annual or _ - semi-annual visual inspection and dielectric break- St NPC000354 36 905098 Vv3Bfr -25- down'voltage test of the aokarel fluid should suffice for routine maintenance chocking over many y e a r s of service. However, many aokarel units were installed in the early 1930s -- before the development of some of the better modern gasketing materials and before Improved designs were developed for sealing out moisture. Such early units should be, and can be, modernized. Leaky or deterio rated gaskets should be replaced. If the askarel has become contaminated, it 3hould be re conditioned. At the same time, a general clean up of the unit and possible refinishing may be desirable. If it is not convenient to take an old transfor mer out of service for general repairs, leaky gaskets can be sealed temporarily by painting over the leaky area with epoxy cement. A survey of users indicates a good number of early-built askarel transformers (over 20 years old) are kept in continuous service in critical installations by the fol.lov/ing steps (instead of modernization). .; , : i !i i\t )i; ji i ' ': .:\f NPC00035437 i i 905099 - 26- The operating units are equipped with compound pressure gauges for reading pressure above and below atmospheric. Positive pressure is main tained on the shell by introducing nitrogen at 2 to 3 pounds above atmospheric. Regular work men in the area daily record the temperature and pressure. If a sudden pressure drop is noted more nitrogen is Introduced and the gaskets are checked for leaks with soap solution. Leaks arc sealed by applying epoxy cement. Modern Sealing Procedures: Transformer purchasers should specify the follow ing modern techniques for sealing: 1. Welding Construction: Covers, radiator con nections, switch and terminal housings, in strument connections, etc. should be welded. 2. Bushing Connections: The most satisfactory bushings are the type with rolled-on flanges and two ring seals rolled into a depression in the porcelain -- scaled with silicone rub ber rings held under compression. Metal-toglas3 or metal-to-porcclain sealed bushings are also satisfactory. If for any reason the above type bushings cannot be used then use a porcelain or glass bushing with a silicone or Viton gasket re- or atoe. tained in a groove/ The gasket can be either NPC00Q354 38 905100 ..-27- rectangular or circular cross section, usually l / k inch thick, 3. Small Size Connections: When not possible to weld, small size connection seals should be made with Flexitallic stainless steel rings. The surfaces must be machined and parallel. The filler between the steel laminations of the Flexitallic ring should be either silicone or Viton. 4. Gaskets For Hand-Hole Covers: Modern design specifies.silicone gaskets. Such gaskets must be retained in a groove. The groove preferably is machined into the flange or cover. However, it can also be formed by welding concentric steel strips to the flange or the cover. Generally the gaskets should be 5/16 to 1/2 in. thick for covers, depending on the depth of the or stop, cross groove/ A rectangular/section is usually used. The silicone material should be Dow-Corning No. 50 Silastic or equivalent. This is a low com pression set material. For best sealing 20 to 25# compression is recommended, with ample or stop clearance in the groove/to allow fur this com pression. No cement is required. With reasonable care the gasket is removable without damage and is re us eable. --' NPC00035439 . 905101 ' -23Si las.tic 50 is slightly swelled by aslcarel which contributes to the tightness of the seal. It Is not deteriorated by aslcarel fluid or vapors. It resists weatherins and it is thermally stable and flexible at all operating temperatures. It is an excellent moisture barrier. Notes: a. Dow-Corning, Midland, Michigan will supply a list of Silastic 50 gasket fabricators to all transformer manufacturers or users. They will also furnish technical data. See Appendix K : Seals, Properties and Pro curements . 0. The Older Sealing Arrangements: The older type gaskets consist of either cork or cork-nitrile rubber combinations or straight nitrile rubber. 1. Cork-Nitrile Combinations: Covers for the main tank, hand-holes, switch and terminal chambers, relief diaphrams etc. are held in place by studs m NPC00035440 905102 -29welued to the flange or by bolts. Tho gaskets are cut''with openings and placed over thebolt3. Often Shellac (Weotinghouse Style No. 1150^19 , or General Electric Company's Glyptal 1276) 13 used to cement the cork to the flanges. The following Is recommended for sealing with the cork -- nitrile rubber combination: Use Armstrong NC-757 cork-nitrile material or equivalent. The gasket can be cut from a single sheet or by scarfing strips of the material. A convenient method for Joining strips is to make a Keystone Type Joint. For this, Westlnghouse, Sharon, Pa., offers their gasket cutter Stylo No. 528 S6l*J G01, (about $15). The joints should be cemented and the gasket also cemented to the flange, using one of the above cements. Excess cement should not be allowed to reach the interior of the transformer. After installation and belting, the outside edge of the gasket should be coated thoroughly with epoxy cement to increase weather resistance. This epoxy cement is a paste to which a curing catalyst is added immediately before use. Typical are:. NPC00035441 905103 -30- a. Epoxy Patch Kit #l-C tfysol Corporation, Clean, N*.Y* b* Scotchcast Resin Minnesota Mining and Manufacturing Co* St, Paul; Minnesota c. Adhesive A-l and Activator Type B Armstrong Products Company Argonne Rd., Warsaw, Ind. d. Adhesive 9860-1, Synthetics Organic Company, Cleveland, Ohio, used with activator diethy lene trianine (Carbide and Carbon Chen. Co*) 2. Straight Nitrile Rubber: When straight nitrile rubber was originally used, invariably the gas ket was recessed in a groove* This was to pre- . vent gasket flow and to protect the material against excessive compression* Although this type seal, was not cemented, the nitrile rubber gasket is not reuseable. Since grooves or stops have already been provi ded for the nitrile rubber seal, Silastic 50 can be easily substituted and is recommended. This conforms with modern practice. XV. Periodic Fluid Inspection and What Checkpoints Mean' On a regular schedule -- at six, nine, or twelve month intervals -- make a simple visual inspection of your askarel insulation and run a dielectric breakdown vol tage check. , NPCQ'00 3544 2 905104 $V:. . -31- A. Visual Inspection: Askarel is a clear, faint-yellow liquid. After'long term-.use this color may gradually intensify to light brown. The fluid should remain clear and free from turbidity or cloudiness. Any color change -- such as to a green, red or blue c a s t -- indicates extraction of impurities (color materials) from the solid Insulation. If a distinct foreign color pick-up is noted, check the complete range of electrical characteristics and notify the transformer maker. Blackening of the askarel may indicate an arcing condition. Other color changes alone are not danger signals since the dielectric breakdown voltage is not likely to be impaired. 3. Dielectric Breakdown Voltage If the dielectric breakdown voltage has decreased significantly from the last inspection, or if it has gradually decreased below 26 KV range (at 2 5 C) -- RON A CHECK FOR MOISTURE. Use ASTM D1533 (Karl Fischer Method). The dielectric breakdown voltage of askarel is the major indicator to the operating efficiency of your liquid insulation. Besides the "visual" inspection __ -- - tests, dielectric breakdown voltage is the only _ - test necessary to run on a routine basis. Wellsealed askarel transformers have service records_of 25 to 30 years on the original askarel. NPC0003S4 4 905105 -32- r :( i XVI. Inspection Check IAst 1. If askarel is clear, even though darkened to light brown, has no sediment or turbidity, has dielectric breakdown voltage over 26 KV ... give it the inspec tion M0K'f. 2. If askarel is clear; has foreign color of blue, green, red ... it is "extracting color" from internal mate rials. This is not, of itself, an operating hazard when the dielectric breakdown voltage stays over 26 KV and moisture remains low. However, this rare occurrance calls for checking into condition of the interior construction and consulting the transformer maker. However, when sampling the fluid care should be taken to avoid getting color into the askarel from paint that may be inside or outside of the sample valve. 3. If the moisture content is found to be above 70 ppm at operating temperature, then sampling should be done at more frequent intervals to establish a possible trend, particularly on out-door installations. b . If askarel is clear, but dielectric breakdown voltage drops to 22 or lower KV, and moisture rises over 80 ppm when sampled at operating temperature ... the __ askarel is ready for simple "refining". If the mois ture is near the saturation level (about 125 ppm at at room temperature) a thorough inspection should be made for water droplets in the transformer tank, oe & t U-Sr:..* fv.f*v NPC 00035444 905106 -33- iind even for "globules" or water floating on the askarel surface. If founds the transformer manu facturer should be consulted for reconditioning both the transformer and the fluid. 5. If askarel is dark brown to black, if black par ticles of carbon are seen, and dielectric strength is low...'-the askarel has been broken down by arcing. It cannot be refined and should be removed and incinerated under proper conditions. (See ANSI Committee C 107 report on Use and Disposal of Askarel and Askarcl-Soakcd Materials. 155 East AAth Street, New York, New York 10017). y ' '***~ ... '--* If any., of these four simple inspection tests appear out of the ordinary, or the relationship between appearance and test values is a b n o r m a l -- contact your transformer supplier for a complete analysis., Whenever a sample is to be shipped to Monsanto, please follow the directions shov/n under: "SAMPLING ASKAREL'1. XVII. Contamination in Transformers Moisture particulate matter and arced decomposition products .are known to be serious contaminating influences on transformer askarel. J41he--power factor test normally used for the detection of contamination in mineral oil filled transformers is of little use for this purpose in askarel filled trans- , ; NPC0003544 5 905107 -34- formcrs is of little use for this purpose in askarel filled transformers, due to the extreme effect of ex traneous soluble polar materials. This increase in power factor as illustrated in Table V has no adverse effect on dielectric breakdown voltage. Table V EFFECT OF COMMON INSULATION MATERIALS ON POWER FACTOR AND DIELECTRIC STRENGTH (HEAT AGED 96 HOURS IN ASKAREL AT 100SC.) Material Immersed BCPPSISMNryhlhrouoaacneepncnnsntlkpehsli.oalb.eea.l(cv.torc.i.af..pac.o..or...ra.n.r.n.r.d..pm..tiu....s.re....bh.a..o.r....ebl.....l..d.d..)..e.....e......r.....hc.............l...y.......o......d.........t......e..h.....................r................e...7.........s...........i...........n...................s....................................................................................................................................................................................... . . . . . . . PPeoeyrrercc.e,8r7.n1556021111tF.........0500005006aa0Act*tCso6k.r0a,rcl After ExposuDSreit1er5leecncCgtr.thic 443433333125079699 KV Similarly, trace contaminants from commonly used construction materials can lower the volume-resi3tivity of askarel, without affecting its dielectric breakdown voltage. Table VI shows thi3 Tabic VI EFFECT OF COMMON INSULATION MATERIALS ON VOLUME RESISTIVITY OF ASKAREL Sample L-- 231...' __ NcaANbdcfg.?...._.eeftwwGGPPGCGehrarrolraaeyaaaplhssnddtpdkeekooeeteaaraanlt.rir!AAA.cccwa!l1gr.ppp.r2ebai.arrrn.s7fee.eepig.t6fsssn.epo.ssscr.wr.ict.nebbbah.ii.ngtopooe.hh.e.aaaa..e.n.ctrrr..aid..dhdt..a,t..a,s..g(.(c.nqa..tlg.nu.ggaa...rr.gme.nii.ae..nnr.).dy.i.c.9g.n..m)fh...a.4t........t.S.a..h.s.e....t..p...od..eh....e...u..r...r..c...si.sr......ie...s.t....m..r...l......a..ia....e.....p.t..t....n...............sU....1..............0.....o0.........0......f.....:...C....C.............. (atVHol)u(mTCe .,R5e0si0stiVvoitlytsxp1r0.*. oOhm.r*cgmap) 21,,900000 1,455723100050000000000 NPC00035446 905108 -35- Whlle trace contamination easily lowers volume resisti vity from high love Is, it Is important to note that heavy contamination (as when arced) does not lower the resistivity below the order of 109 ohm-cm. at 100C. The different behavior of askarel vs. mineral oil in these respects can be summarized as follows: High power factor and low volume resistivity in transformer mineral oils are commonly re garded as "danger signals" that the oil has deteriorated and broken down chemically or excessive moisture is present, . `" This is NOT TRUE of askarel liquid insulation, unless the dielectric breakdown voltage is low, or the moisture content is high. Manufacturers of askarel type transformers point out that it is quite well known that askarel transformers with initial power factor of the askarel fluid in excess of 59^ at room temperature and 60 Hz are giving satis factory service life. However, there needs to be assurance that both dielectric breakdown voltage and moisture are at satisfactory levels and do not show adverse trends. NPC00035447 -.a?i 905109 -36- XVIII. AS.TM Method For Investigating The Compatibility of Transformer Insulation and Construction Matex'ials in Askarels This method, which is presently in process of publi cation by A5TM, uses the change of electrical and/or chemical characteristics of transformer askarol result ing from controlled exposure to insulation and con struction materials, to evaluate their immediate major "contamination" effect on the askarel fluid. Delayed or long time "contamination" effects may not be detected. The method also utilizes various physical tests on the insulation artd construction materials after controlled exposure to the a3karel to determine the compatibility of these materials with transformer askarel. Properly proportioned specimens of the insulation or structural materials are Immersed in refined a3karel for 168 hours at 100ilC In a forced draft oven. Changes in electrical and chemical properties of the transformer askarel are compared against a control sample of the askarel treated in the same manner, in absence of the test specimens. Dissipation factor, (ASTM. D92*0, change is one of the criteria ' used. The askarel fluid i3 refined by adsorb- tive treatment to a dissipation factor level of 0.05 max. -- at 100C and 60 Hz and 0,01 max. at 25C and 60 Hz. NPC000 J`544- 905110 -37 Corresponding values of the askarel fluid after heating 168 hours at 100C in absence of a test specimen are 0.075 and 0.02 respectively. The maximum dissipation XIX. factor levels suggested for the askarel after heating in presence of the test specimen are 0.20 at 100*0 and 60 Hz and 0.04 at 25C and 60 Hz. Refining Askarel For Re-Use A. Filtering Through Dry Blotter Paper to Remove Mois ture and Extraneous Particles: Most operators prefer portable refining apparatus, such as a plate press fitted with a dolly, (avall- _ able from Sparkler, Mundelein, 111., or General f-Electric Co.,.Pittsfield, Mass); or the earthen vyi.'i cartridge filter type, (available from Industrial Filter Corp., Lebanon, Ind.). Filter paper liners for the plate press are available from Carl Schleicher and Schuell Company, Keane, New Hampshire and manu facturers of filter presses listed above. The filter paper must be dried. Immediately before use. For best results, spread the paper for maximum surface exposure in a hot air circulating oVen and heat it for 4 to 6 hours at 110C. NPC00035449 ;c 905111 uv iu*.,-.*'V. -38- Circulate 'the-.askarel hot (but not over toC) through the filter, fitted with the dry. paper' liners. After filtration the dielectric breakdown voltage of the askarel should be 35 KV minimum. 1. Precautions: Filtering should not be done when the relative humidity exceeds 7 5 /6. 2. Any flexible hoses and gaskets on the refining equipment should be lined with or made of mate rials that will not be softened by contact with askarel fluid. ^ (Silicone or VIton or Teflon-.' v .. lined/ or flexible metal materials are suitable.) Table VII G U ID E 'T O -R A T E O F DISSO LV ED -W A TER R EM O V A L 11Y F I I . T F R f . N G . A S K A R E L T H R O U G H A P A P E R P R E S S Pass* Through Paper Press 0 l .2 3' 4 5 6 W ater in A sk a rti PPM in 35 22 - 18 12 10 10 B. If the solid insulation of the transformer requires drying, consult the transformer manufacturer or an apparatus service shop, as in such case oven drying is preferred. NPC00035450 905112 -39- C. Earth Treatment for Maximum Improvement of Power Factor and Volume-Resistivity: Note, however, that pumping and filtering, the fluid to achieve, for example, only a change in power factor or volume resistivity alone is said to be bordering on irresponsi bility in today's ecological climate regard ing PCBs. 1 Procedure: (The askarel liquid should be relatively dry prior to the following earth filtra tion. Use finely divided Attapulgus clay or Fuller's earth (dried and activated by heating for 12 hours at 300-350F immediately prior to use) as a coating on the filter paper surface. The amount of earth used should be 0 .1 to 0.2 per cent by weight on the weight of the askarel to be treated. (Askarel weighs about 12.5 pounds per gallon). To deposit the earth evenly, stir one-third of the earth with a small portion of askarel in a clean container. Pump the mixture through the filter and Pullow with two more one-third por tions. Then circulate askarel taken from near the top of the transformer, pass it hot (not over 55-6o *C) through the earth coated filter and feed back through the bottom transformer NPC00035451 905113 outlet. Continue circulation until the fluid is clear and tost shows that the electrical, properties are fully restored. 2, Effect of Earth on Removal'of Scavengers: Only slight and.-insignificant, loss (by selec tive absorption of tin tetraphcnyl and epox ides occurs when askarel is refined by treat ment with 0 .1 to 0.2 per cent by weight of earth. To remove significant amounts of the scavengers requires repetitious treatment with much larger amounts of earth. 3. Table IX --Approximate Relationship Showing U- " . -L-i :*' '- --' ' the Insignificant Effect of Power Factor and Volume-Resistivity on Dielectric Breakdown Voltage of Transformer Askarel: Power Factor Volume Resistivity x IQ? chm-cm (at Breakdown looor- 25%% 155 I-25JS >-50^5 mi 0.05/ 0O2...70I%%55 : -, ' DC, 0.1" gan) 1500 500 100 60-70 25 25C, 0.1" 3333355555 KV XX, Cleaning Arced Transformers If a unit has arced so that the askarel is no longer fit for use, a thorough cleaning of the unit is necessary be fore refilling with new askarel insulation and returning it to service*. Follow this procedure: Tty Drain out all dark/ carb .n-contarinated askarel. _ -Arrange to have the scrap fluid incinerated under proper conditions.: (iee ANSI Committee C107 report.) .. Th u - ` NPC 0 0 0 3 5 4 5 2 905114 -41- B. Carefully brush carbon deposits from internal parts and Insulation, using a soft bristle brush making sure that insulation is not damaged. C. Plush thoroughly using new askarel (not an oil, not a cleaning solvent). D. Plush a second time with fresh askarel; drain; then fill to the proper level with new askarel. E. .Energize-, transformer to warm the fluid for 24 to 48 hours; then circulate the askarel through a filter, returning it to the unit filtered and ready for use. ' s assumes that the cause of arcing has been established and corrections made. When severe arcing occurs, major repairs are usually necessary and the unit rebuilt. This procedure can be applied for flushing out repaired units. XXI. Sampling Askarel Take a sample as close to the top of the liquid surface as possible. (Many large askarel transformers have a built-in sampling tube near the surface for convenient sampling). Then, to make sure that your SAMPLE truly represents your askarel insulation, take another sample from the bottom. If additional sampling tube connec tions are contrived on the valves for easier sampling, _-- make the tubes of clean glass, stainless steel, aluminum _ or tin for rigid types; and silicone or Viton or Teflon tubing for flexible types, _ < v t a Z u S B B N P C Q O O 3S4s 905115 -42-. Use NEW containers for the askarel sample. A new and thoroughly pre-dried small-mouth quart glass bottle fitted with a Bakelite screw cap fitted with an alumi num or tin bottle cap liner is recommended for "quick on-the-site testing". (If complete analysis is to be made, a 5-pint size sample is required). Be sure that the new bottle does not stand open to col lect dust or moisture. Rinse the sample bottle and cap lining two or three times with askarel from the trans former; then fill it. If the sample will be tested prompt ly, a clear glass bottle oaj? be used. If sample is to be stored indefinitely>-useaan amber glass bottle or wrap clear glass with aluminum foil. A. Select a dry. day. Do not sample insulation on a warm, moist day when humidity exceeds 75& and ... B. Make sure that the askarel is at least as warm as the surrounding air. (Cold liquids can condense moisture from humid air.) C. When sampling askarel from transformers, it is best to take the sample when the unit is warm and opera ting at average or majciir.um load. Especially as a check on moisture (as reflected by a dielectric breakdown voltage test), sampling the warn askarel IE- more truly represents its condition during operation. NPC000 35 454 905116 -43-, Experience shows that water will migrate from a transformer's solid insulation to the askarel liquid and vice versa, depending on temperature. Therefore, when the transformer is hot, the mois ture is most likely to be found in the liquid. This accounts largely for periodic variations in dielectric breakdown voltage. Por example: a relatively high dielectric breakdown voltage may be found during winter months and a relatively low dielectric breakdown voltage during the summer months on samples taken from the same unit. NPC00035455 905117 UH- Section B ASKAREL FILLED SWITCHES AND TERMINAL CHAMBERS I. INTRODUCTION High -.voltage .leads; arc usually connected to askarel or mineral oil-filled network transformers and power centers through terminal chambers and switches. In some cases terminal chambers are not used, and the high voltage leads are connected directly to the switch terminals. They may bo filled with either aslcarel or mineral oil. Switches are usually rotary or drum type fitted with a revolving block and porcelain unit as the principal element arranged for three-phase service. (A cutaway view of a typical m f o r reference.) Askarel transformers with attached switches have been in use for about 30 years. then they wore first Introduced, the availability of insulating and gasketing materials was rather limited and even the best materials at the time had no service history. As a result, Inadequate gasketing materials such as cork/ nitrile rubber, and nitrile rubber^iiPeork particles were used., '.'hile satisfactory for a NPC000 35 456 90577Q -45- limited period cf tine, these materials cannot be depended on Cor the expected long life of the equipment. The terminal chamber is usually above or below the switch compartment and separated by a steel wall through v/hich the bushings are inserted. When bushings are properly selected and correctly installed, there is no leakage from one com partment to the other. With poor bushing seals, and the terminal chamber above the switch, potting compounds or cable oil can seep into the askarel. When the terminal chamber is below the switch, askarel can drain into the terminal sources of contamination for askarel in switches and terminal chambers; they rank in this order of frequency: (l) water entering through poor gaskets; ( 2 ) decomposition products from arcing when switch is used tc break magnetizing current; (3 ) entrance of pothead or cable conpounds through leaky bushing seals. Unlike an askarel transformer where the amount of contami nant is likely to be very small (probably only trace amounts) in relation to the volume of askarel fluid -- in switches or terminal chambers with faulty seals, the amount of contami nation can be relatively largo. "y NPC000354V' 905119 Experience has shown that, based on the number of installed askare1-switch units, the percentage of failures is extre mely small, When investigated, It has been found that most failures originate in the switch chamber. Water is the chief source of contamination. However, heavy contamination of askarel with petrolatum and asphalt material, due to leakage, have caused a few.failures. Petrolatum is used frequently for filling terminal chambers. When either cable oil or petrolatum seeps into askarel, no great harm results. The fire resistance will be somewhat decreased and power factor of the askarel will increase with an accompanying drop in resistivity. While highly undesir able, it is doubtful-that failure of the unit results. Where asphaltic compounds are used in place of petrolatum, the danger is increased somewhat because asphaltic contamination may cause excessively high dielectric losses in the askarel. When the terminal chamber is below the switch chamber, the potting compound can be contaminated by askarel if the bush ing seals are leaky. This is undesirable because the askarel will increase the power factor and conductivity of the potting compound or cable oil and develop heat from dielec trie loss. If this mixture is drawn into the cable Insulation, a cable failure is likely. This again emphasizes the Importance of tight bushing assemblies. NPC 00035458 905120 .-47- ' 'v III. SEATING SWITCHES AND TERMINAL CHAMBERS Pruper bushing construction, .-use of Silastic seals and avoiding wherever possible is highly desirable (as covered in Section A). Whore an elastomeric seal is to be used in contact with both askarel and petroleum oil, DuPont's Viton is suggested. if*-iiit'v' For new equipment the user should specify these modern sealing arrangements to keep out contaminants and minimize maintenance; JV. ASKAREL USED UNDER MILD ARCING CONDITIONS ^5;.The IEEE Guide for Transformer Askarel calls attention to he*following: "Askarel is used, to some extent, in apparatus where it is subjected to light intermittent arcing, such as in self-contained induction regulators, where operating switches are con tinually producing slight arcs, In transformer 'deenergizing switches, etc. Under normal con ditions, deterioration of the askarel is very slight. However, improperly adjusted or defec tive switches in this type of apparatus can produce excessive and prolonged arcing and acccllerated deterioration of the askarel. It is recommended that when askarel is used under those conditions, checks of the liquid, espec ially for moisture and dielectric oreakdown voltage made more frequently than when it is used only an a cooling and Insulating fluid. Deteriora tion of this type is indicated by a blackening of the liquid. It can usually be reconditioned as previously desoriood. Special attention should be given to maintaining the scavenger at the appropriate concentration .ft ^ NPC0035459 905121 -i3- V. MAIj-ITZINA?:Ci FOR ASKAREL FILLED SWITCHES A. Switches used for grounding''after' power oourcc has been '^Wv de-energized will not undergo arcing. 13. Switches interrupting, magnetizing-current will be sub ject to arcing ; the- amount of deccrnposi tion 'wi 11 depend on power interrupted, time and frequency of operation. As a general rule, the liquid should be checked after 5 to 10 operations. 1. On nev/ly installed switches, check the askarel at 3 , 6 and 12 month intervals; if found satisfactory, check once annually thereafter. With proper atten tion to the gasketing of covers and bushings, exper- 1 ience will probably indicate that less frequent in spection 13 warranted. 2. Check askarel. for: a. Dielectric breakdown voltage (ASTM D77): It should voltage be 26 KV minimum. If dielectric breakdown/is low, confirm presence of water by Karl Fischer method ASTM D-1533. Filter to remove moisture. Die - lectric strength should then be 30 KY minimum. b, Presence of carbon from arcing: Fluid should be relatively free of carbon. If badly, arced and very black, replace fluid. If only minute, amounts of carbon are present, filtration is recommended. Check power factor of liquid (should not be over 5# at 25C. and 60 cycles). Flush out switch .- chamber with several gallons of fresh askarel before refilling. ._ . `'.yi ' *K.-as-: NPC00035460 905122 -iKJ3. If charo is discoloration, high power factor, detectable cnange in specific gravity or refrac tive index, or if fluid flashes below 250R, there is a possibility of seepage of potting com pound Into tho switch compartment. In this case, correct any leaky bushing seals with proper re placements and fill with new askarel. 1. If terminal chamber is below switch, check potting compound for presence of askarel (can usually be . detected by odor or by an increase in specific gravity). If askarel is present, correct any leaky bushing seals.with proper replacements, and renew compounds. 5. Examine cover gaskets visually. Deterioration can be detected by swelling and cracking of the exposed edge. In cases of severe deterioration, liquid seepage is usually present. 6. Check for leakage at packing gland of switching shaft.. If leaking, repack with a Silastic ring type gasket. VI. ASKAREL UTIDER EXCESSIVE TEMPERA!".JRE CR FAULT' CONDITIONS! The IEEE Guide also points out that, ''Chlorobenzenes used in transformer askarels tcjgin to boll NPC00035461 905123 -50- al; temperatures of about 205C, under atmospheric con ditions. If the material is heated to such high tem perature in a sealed system, pressure develops. Pres sure will also develop in the system if the askarel is arced sufficiently to generate copious hydrogen chloride "Therefore, it is recommended that wherever possible, sealed askarel filled equipment be provided with pressure relief devices. Those devices must bo large enough to provide immediate relief at a definite pressure, and to prevent further build up of pressure if decomposition continues. It must be remembered that the presence of devices of this sort does not necessarily preclude the rupturing of containing vessels, since pressure build up can be extremely, rapid' under violent arcing conditions." N P C 000 S 4`* . 905124 -51- SE C T IO N C A N A L Y T I C A L S E R V I C E S O N TRANSFORMER ASK A R E L AVa ILAIILF, , FROM MONSANTO T ra n sfo rm er users not w ish in g to m a k e their o w n fluid analyses can o b ta in the service fro m M o n sa n to . S im p ly contact M o n sa n to and specify w hat analyses arc w anted. Y o u will be sent the p ro p er-sized 'sa m p le container^ I. W h e n y o u r e c e i v e t h i s , c a r e fu lly tak e y o u r s a m p le ( f o llo w in g the p r o c ed u r e for s a m p lin g in this guide). S en d the contain er to M o n sa n to 's laboratory. Charges listed include sam ple container, shipping, handling and laboratory costs. T ypes of A nalyses Availuble Anaivsis I) R O U T IN E M A IN T E N A N C E C H EC K T otal Charge: $ 2 5 . 0 0 T o d e te r m in e th e g en era l c o n d it io n o f th e flu id a n d A nd w h e th e r fu rth e r a n a ly s is is n e c e s sary. (on e-q u art sam p le required) w -V.>v Properties Tested C olor and C ondition Dielectric Breakdown Voltage ^ - "r ^ M oisture Y o u w ill b e n o tifie d o f th e results o f th is test. I f fu rth er testin g is in d ic a te d , a n d y o u w a n t a c o m p le te a n a ly sis, y o u w ill be sent a five-pint sa m p le contain er. T h is s a m p le will4>c u s^ l for the follosvin g series o f tests: * Analysis 2) C O M PLETE A N A LY SIS Total Charge: $ 5 5 * 0 0 (a) T o d e te r m in e the extent- o f fluid c o n ta m in a tio n , (b) earth refin em en t to d ete r m in e w hat d e g r e e o f r e s t o r a t i o n o f e le c t r ic a l a n d i n s u l a t i n g p r o p e r tie s is p o s s i b l e , ( e ) c h e c k te st to see h o w the fluid resp on d ed to earth treatm en t. a) C o m p le t e A n alysis: to d eterm in e the exten t o f c o n ta m in a tio n Properties Tested Color and Condition Specific Gravity Refractive Index Water Free Chlorides _ -Acidity " D T e n r c tr ic Breakdown Voltage --P o w e r F a c t o r , D i e l e c t r i c C o n s t a n t , a n d R e s i s t i v i t y - x :':3 NPCO 0 0354 6 3 905125 -52- b) Earth R efinem ent'.R esponse: C o n sists o f treatm ent for 2.5 hours at 5 0-60C . w ith 0.1 to 0.2 percent by w e ig h t c f properly c o n d itio n e d A tta p u lcu s clay a n d -th e n filtraticn. th ro u g h dry filter p a p er. c ) A n a ly s is A f t e r Laboratory E a rth R e f in e m e n t : Properties T ested Refractive index W ater Free Chlorides A cid ity Dielectric B r e a k d o w n V o l t a g e Power Factor, D ielectric C onsiant, and R esistivity Y o u will be n o tifie d o f th e results o f this test ser ie s o n y o u r s a m p le . T h en a ftei r e f in in g y o u r en tir e t r a n s f o r m e r fluid fill y o u c a n c h e c k o n th e r e s u lt s b y r e q u e s t i n g t h e follow ing analysis: Analysis 3) A N A L Y SIS AFTER E A R T H R E FIN E M E N T :$35T o t a l C h a r g e . o c ( T h i s ch arge will not a p p ly w h en analyses l and 2 have already been m ade.) $ * T o d e te r m in e w h e th e r th e e n tir e lo t o f th e a sk a r el fill r e s p o n d e d to t h e s a m e e x t e n t , boratory sam ple, (five-pint sam ple required) Properties Tested Color and C ondition Refractive Index W ater Free Chlorides A cid ity Dielectric B r e a k d o w n V o l t a g e Power Factor, D ielectric C o n ta in , and R esistivity T o arrange for ehe tests d e sc r ib e d a b o v e w rite to th e f o llo w in g a d d ress: Pau! G. B enignus M onsanto C hem ical C om p an y 800 North L indbergh Bivd. St. Louis 66, M issouri .Samples to be tested sh ou ld be clearly m arked for iden tification an d sent d irectly to: M onsanto C hem ical C om p an y W. C . Kru'rnmrich L a b o r a to r y S a u g e t , Illinois Attention: R. K ster 22 'sms'tei&-:;- NPC0003546 4 905126 -53- APFEN DEC APPENDIX A -- Askarel Stability and Composition of Arc Formed Gas: Askarel insulation Is one of the most inert., -chemiea ily-stable heat resistant, non-corrosive liquids known. It will net. break down, oxidize or sludge when exposed to air and high tempera tures, 150C,. or even somewhat higher. Arcing, however, will break down the compound to liberate some hydrogen chloride and small amounts of carbon. APPROXIMATE COMPOSITION ARC FORMED GAS FROM TRANSFORMER ASKA REL BLENDS ASTM TYPES D AND F (INERTE2N 5^201KA AND PYRANOL A 13B3B-2 / .RESPECTIVELY) Gas Amount carbon monoxide......................... 0,3 per cent carbon dioxide........ ........ . 0.3 oxygen.............. '0.6 inert gases........... 1.5 hydrogen chloride .......................97.3 (note the absence of phosgene) This arc-formed gas from ASTM Type D and Type F transformer askarels is.non-flammable and non-combustible. For all practical purposes, the amount of gas liberated from iskarel under a given set of arcing, conditions is about 100 cubic centimeters per kilowatt-second. Wi-- NPC00035465 905127 appendix b SOLTDILITY OP CAS IN TRANSFORMER ASKARF.LS ASTM TYPES D AMD F Percent of Gan By Volume Corrected to: Carbon dioxide Air Nitrogen Hydrogen chloride-1 25C 7o0 mm ~1T<-- -- I'ornr 65..07 4.9 4.8 37.3 50.9 oc. 760 mm 25rrC T?oo 5~8 5.0 5.5 4.4 1) in absence of scavenger APPENDIX C EFFECT CF TEMPERATURE CN DIELECTRIC BREAKDOWN VOLTAGE OF ASKAREL Temperature C -60 -40 -20 0 20 . 40 60 80 Dielectric Breakdown Voltage ------------A-S~T5M7~KD8v7-7--- !---- 63 57 55 50 BO 48 45 NPC00035466 905128 -55- appendix D Temp.aC -20 0 2k 00 6o 80 '100 COMPARISON OP THE APPROXIMATE VISCOSITY IN SAYDOLT UNIVERSAL SECONDS OF TRANSFORMER ASKA RE.LS AND M INERA L 01L Pyranol A13B3B-2 1,000 100 70 1*5 39 3'+ 30 10-C Mineral Oil 1,000 150 85 1*9 1*0 311 30 Inerteen ^1*201 KA 57C00 195 85 50 1*0 36 33 APPENDIX E THE DENSITY OF INERTEEN 5^201 KA 7335-9 AMD TRANSFORMER PYRAHOL A13B3B-2 Approx. Density gm/cc. Inerteen 5^201 KA ----- ^.5575U2'" ----- 1.529 1.507 1 .1*85 PyranoTl7 5 A7 713B3B-2 1.555 1.532 1.510 1.U88 APPENDIX F The thermal conductivity values of transformer Pyranol A13B3B-2. at 27`JC and 58C are 26.2 and 2?.8 x 10"5 calories centimeters'^, degrees centigrade' , second", respectively. Or, approximately 0.0 3TU per (hr. )(c`i.ft .)(F. ) per foot. This same approxima tion applies to Inerteen PPO (7336-9). APPENDIX G Heat Capacity Over the temperature range of 254 to 1250 the specific heat or tt-ansformer askarel Is d o s o to 0.30 calories per gram per degree. APPENDIX' Coefficient of Expansion The average coefficient of expansion of transformer askarel the temperature range 20 tc 1QC Is 0.0007 cc/cc/C. Cne g a , lor. viould increase to 1 .05 gallons on heating from. 20 to- 10u' fSJg&hgg NPC0003546' 905129 -55- APPENDIX .1 F i r e R e s 1. ls l a n c e Askarcls of various compositional types are used. Under arcing conditions the gases produced, while consisting of predominantly non-combustible hydrogen chloride can yield varying amounts'of combustible gases depending upon the askarel type. Insulation systems incorporating these askarels and cellulosic or other organic materials may, when arced, produce gaseous mixtures which are moderately flammable. As a precaution, such gases should be removed from the askarel by bubbling dry nitrogen through the askarel and flushing the gas space with dry nitrogen before any work is performed on the apparatus. AFPENDIX J Seals, Properties and Procurement Dow Corning Corporation, Midland, Michigan with Districts at Atlanta, Boston, Chicago, Cleveland, Dallas, Dos Angeles, New York City, Washington, D.C. and Toronto has available Bulletin 09-01^, August 1962 entitled "Silastic Design Data". This lists, the gasket fabricators throughout the country from whom the "Silastic 50" gasketing can be purchased in sheet, extrusions or molded shapes, Generally Silastic ^0 shset goods are stocked by local die' cutters, hence, could be generally purchased locally. Usually small. Quantities of gaskets are die cut. If larger quantities are needed, tools are made of the same type used to cut other elastomers. **.<v NPC000354 68 905130 -57- Where the gasket, in extruded for fitting Into a machined groove or between gasket stops, Dew-Corning advises use of a scarved joint. This Joint is then cemented us.Ing Dow Corning* 3 Silastic .1^0 (clear) or their RTV 731 (white) mate rials, which air euro, Dow Corning points out that the local ''rubber" fabricators purchase the Silastic 50 in billet form. This Is worked on a roll mill in preparation for sheeting or extrusion. Then to obtain the desired physical properties the fabricator must oven cure the Silastic 50 fo.r 2 k hours at U8oF. SPECIFICATIONS* ASTM DS76 ASTM D4-12 ASTM D*412- ASTM D595 Color........ ............. ___White Specific Gravity at 77F... ___ 1.20 - 0 02 Hardness, Shore A. Scale... --- ^5 to GO Tensile Strength, psi, min. ___ 800 Elongation, Compression percent, Set after mi2n2..h.r ___ 250 s ,.. at 300F, percent, max.... .... 30 *'All physical properties measured on 0.075 inch thick samples molded 5 minutes at 240P, and oven cured 2 ,\ hours at 'i80P. NPC00035469 905131