1、UDC 665.765 : 621.892.25 : 620.193.23 : 542.93 DEUTSCHE NORM Amil 1979 Testing of lubricants TEST OF THE BEHAVIOUR OF LBRICATING GREASES IN THE PRESENCE OF WATER - DIN 51 807 Static test Part 1 I Prfung von Schmierstoffen; Prfung des Verhaltens von Schmierfetten gegen- ber Wasser, Statische Prfung D
2、es ignationz DIN principal number Part number I Field.of application Lubricating greases 2 Purpose The purpose of the test method specified in this standard is to determine how lubricating greases behave in the presence of distilled water under static conditions at various temperatures. Note: The te
3、st result represents only one characteristic property. No firm conclusions can be drawn from the test result as to the range of appli- cation of the lubricating grease tested or as to its stability in the pre- sence of water under the diverse conditions in practice. 3 Other relevant standards DIN 12
4、 395 DIN 51 750 Part 1 DIN 51 750 Part 2 Testing of mineral oils; sampling; substances with the DIN 51 848 Fart 1 Testing of mineral oils; test errors; general; defini- DIN 53 135 Filter paper for chemical analysis; classification, DIN 61 640 Dressings materials; absorbent cotton wool for medical La
5、boratory instruments; test tubes Testing of mineral oils; sampling; general consistency of ointment, and solid substances tions and their use in conditions of delivery marking, principal properties, test methods use 4 Concept By behaviour of lubricating greases in the presence of water in the sense
6、of this standard is meant the action of still water of defined origin at various temperatures on lubricating greases not under mechanical stress. 5 A layer of lubricating grease applied to a glass strip is subjected to the action of still water. After a test period of 3 hours it is observed whether
7、and which signs of change according to clause 11 have appeared. Brief description of the method 6 Desgnat.aa of the method Designation of the method of testing a lubricating grease at 40 OC and 90 OC in accordance with clause 10: Continued on pages 2 to 5 Solesale rightsof German Standards (DIN-Norm
8、en) are with Beuth Verlag GmbH. Berlin 30 DIN 51 807 Part I Engl. Price group Sales No. 0104 05.82 Page 2 DIN 51 807 Part 1 7 Apparatus Glass strips of 15 mm in width, 190 mm in length and about 3 mm thick metal templet, 1 mm thick, according to the figure. The dimensions shown in brackets in the fi
9、gure are given as example and are not binding. The templet may also be provided with stops and guides for the glass plates. test tube 20 according to DIN 12 395 heating equipment, e.g. oil bath, water bath, thermostat or hot cabinet, which enables the temperature to be held constant to 2 1.5 OC duri
10、ng the test period. Metal templet DIN 51 807 Part 1 Page 3 8 Chemicals and test agents Solvent for cleaning purposes any volatile, hydrocarbon-based solvent may be used. For example, limited boiling range light petroleum DIN 51 631-1, petroleum ether DIN 51 630-A or tetrachlorethane (perchloroethyle
11、ne) according to DIN 53 978. water By water is meant once-distilled water or water which has been deionized (completely freed from salts) by ion exchange. Note : “Softened“, “demineralized“ etc. water may not be used, since in contrast to distilled or deionized water it contains salts in the ionized
12、 state dissolved in varying form and amount; it may therefore show a different chemical behaviour from that of distilled or deionized water and is considerably less aggressive. absorbent cotton wool DIN 61 640 - V - Bw filter paper 9 Sampling According to DIN 51 750 Part 1 and Part 3 10 Procedure Th
13、e glass strip is cleaned with solvent and dried with filter paper. The templet is placed tightly on the glass strip to prevent migration of lubricating grease beneath it. The lubricating grease is applied as free as possible from air bubbles. It must fill the cut-out part of the templet without void
14、s. After removal of the templet the sample must show clean edges and a uniform thickness (1 am). The test temperature is (40 2 i) OC or (90 f 2) OC. If a lubricating grease is to be tested at both temperatures, a newly coated glass strip is to be used for each test. The glass strip with the applied
15、coating of lubricating grease is introduced into the test tube with water at the test temperature so that the lubricating grease sample is immersed to a length of about 80 mm. The open end of the test tube is to be closed with a plug of cotton wool, which reduces evaporation of the water. The loaded
16、 test tube is placed in the heating equip- ment at the test temperature and allowed to remain there for the period of 3 hours I 5 minutes. 11 Evaluation At the end of the test period the glass strip is removed. The portion of the lubricating grease sample which has been immersed is immediately exami
17、ned with the unaided eye and the rating assessed according to the table. Page 4 DIN 51 807 Part 1 1 2 Description I 1 s 1 ight change colour change (lightening) of the lubricating grease surface due to a slight water absorption b the surface layer of the lubricating grease incipient solution of the
18、lubricating grease, observable by the formation of a yellowish-white slimy surface film and moderate to severe turbi dity of the water moderate change I O I no change severe change none of the characteristics named under the following ratings partial or complete solution of the lubricating grease, u
19、sually with seperation of oil and thl formation of a milky-white oil in water emulsion 3 12 Reporting of the result As the result of the test, the rating according to the table and the test temperature are cited, with reference to this standard, e.g. for a lubricating grease with which the colour ch
20、ange of the lubricating grease surface is detect- able after testing at 40 OC: Rating DIN 51 807 - 1 - 40 13 Test errors (according to DIN 51 848 Part 1) To assess the reliability of the results, the following characteristics are used: Repeatability (one observer, one apparatus) If two results are f
21、ound by one observer under repeatability Conditions, both results are considered as acceptable and in accordance with the standard if the ratings are the same. Reproducibility (different observers, different apparatus) If one result is obtained in each of two different laboratories under repro- duci
22、bility conditions, both results are considered acceptable and in accordance with the standard if they do not differ by more than one rating step. Further standards DIN 51 630 DIN 51 631 DIN 53 978 Mineral spirits; petroleum ether; requirements Mineral spirits ; special boiling point spirits ; requir
23、ements Tetrachloroethane (perchloroethylene); requirements and tests for ex-refinery material Explanations This standard was prepared by Advisory Committee “E 662 “Testing of lubricating grease“ in the Fachausschuss Minerall- und Brennstoffnormung (Special committee mineral oil and fuel standardizat
24、ion (FAM) of the Normenausschuss Material- prfung (Standards Committee Materials Testing). Compared with DIN 51 807, January 1972 edition, essentially the following changes have been made: DIN 51 807 Part 1 Page 5 Because of the small informative value, testing at 20 OC is omitted. The test temperat
25、ure of 50 OC is dropped in favour of a test at 40 OC. The test duration is reduced from 5 hours to 3 hours. Experiments have shown that a test period of 3 hours is adequate for a precise determination. The designation 1 a (rating) is changed to O and 1 b to 1. Metal strips are used in this subsequen
26、t edition, because generally metal sur- faces are lubricated and this seemed consequently to be closer to practice. Experiments have shown, however, that there is no difference in the results with glass and metal strips. Even metal strips with different roughness grades gave the same results in comp
27、arison with glass strips. In an interlaboratory test carried out by the Special Committee on mineral oi.1 and fuel standardization (FAM) good agreement was achieved and the precision cited is derived from this. It is intended at a later date to extend DIN 51 807 to include a dynamic test. Appropriate work has been initiated by the Advisory Committee FNM 662 “Testing of lubricating greases.
