1、BRITISH STANDARD BS 2626:1992 Specification for Lubricants for refrigerant compressorsBS2626:1992 This British Standard, having been prepared under the directionof the Petroleum Standards Policy Committee, waspublished under the authorityof the Standards Boardand comes into effect on 15June1992 BSI
2、06-1999 First published September1955 Second edition August1975 Third edition June1992 The following BSI references relate to the work on this standard: Committee reference PTC/7 Draft for comment88/50871 DC ISBN 0 580 20501 0 Committees responsible for this British Standard The preparation of this
3、British Standard was entrusted by the Petroleum Standards Policy Committee (PTC/-) to Technical Committee PTC/7, upon which the following bodies were represented: Ball and Roller Bearing Manufacturers Association British Coal Corporation British Fluid Power Association British Gear Association Briti
4、sh Lubricants Federation Limited British Railways Board British Steel plc Department of Transport Electricity Industry in United Kingdom Engineering Equipment and Materials Users Association Institute of Petroleum London Regional Transport Ministry of Defence The following bodies were also represent
5、ed in the drafting of the standard, through subcommittees and panels: British Refrigeration Association Institute of Refrigeration Amendments issued since publication Amd. No. Date CommentsBS2626:1992 BSI 06-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Sampl
6、ing 1 3 Composition 1 4 Appearance 1 5 Physical and chemical characteristics 1 6 Grade designation 2 7 Integrity of containers up to5l containing type A lubricant 2 8 Precision and interpretation of results 2 9 Packaging and marking 2 Appendix A Explanatory notes on refrigerant compressor lubricants
7、 3 Appendix B Method for detection of free water in type A lubricants (the crackle test) 6 Appendix C Method for determination of content of material insoluble in Refrigerant12 at 40 C 7 Appendix D Method for determination of the integrity of containers filled with type A lubricant up to and includi
8、ng5l capacity 11 Figure 1 Typical refrigerant/lubricant solubility/viscosity diagram 3 Figure 2 R22/lubricant phase separation characteristics illustrating typical variation in type A and type B lubricants 6 Figure 3 Example of test cylinder with aerosol valve and transfer tube 7 Figure 4 Filtration
9、 apparatus 10 Figure 5 Schematic illustration of the procedure for determination of integrity of filled containers 13 Table 1Physical and chemical requirements for refrigerant compressor lubricants 1 Publication(s) referred to Inside back coverBS2626:1992 ii BSI 06-1999 Foreword This British Standar
10、d has been prepared under the direction of the Petroleum Standards Policy Committee. It supersedes BS2626:1975, which is withdrawn. In preparing this revision the Committee noted the effect that the “Montreal Protocol on Substances that deplete the Ozone layer” will have on the development of refrig
11、erants and suitable lubricants. The Committee was aware that the refrigerant used in the method for determination of material insoluble in Refrigerant12 at 40 C has been shown to be among those compounds believed to have a significant depleting effect on the ozone layer. However, it was agreed to re
12、tain this refrigerant in the absence of a suitable equivalent substance that is not harmful in the same sense. This British Standard defines lubricants suitable for use in systems containing commonly used refrigerants. No attempt has been made to recommend lubricants for specific applications as it
13、is considered that this is the responsibility of the plant manufacturer or designer. The lubrication of compressors in vapour compression refrigerating systems generally demands special or enhanced properties that are not normally possessed by, or necessary in, mineral oils used for the lubrication
14、of other types of plant. This is because the lubricant may be transferred from the compressor to other parts of the refrigerating system where it will be exposed to extremes of temperature and may also come into contact with varying amounts of liquid or gaseous refrigerants. These refrigerants may b
15、e fully miscible, partly miscible or practically immiscible with lubricants. The intimate contact of oil and refrigerant under varying conditions of pressure and temperature may determine the choice of lubricant and the test methods used to evaluate its performance. For particular combinations of sp
16、ecific refrigerants and extreme temperatures, the use of special lubricants may be necessary and such lubricants are outside the scope of this standard. CAUTION. In relation to potential health hazards and to precautions recommended for persons regularly in contact with mineral oils over long period
17、s, attention is drawn to the following advisory notices: available from the Employment Medical Advisory Service (EMAS) of the Health and Safety Executive and from whom further advice may be obtained. Attention is drawn to the Health and Safety at Work etc. Act1974 and the need for ensuring that the
18、methods specified in this British Standard are carried out with suitable precautions. MC (B4) Skin cancer caused by pitch and tar MC (B5) Skin cancer caused by oil MC (B6) Save your skin. Occupational contact dermatitis MC (B9) Save your skin. Advice to employers MC (B10) Save your skin. Wear gloves
19、BS2626:1992 BSI 06-1999 iii The principal differences between BS2626:1975 and this standard are as follows: a) the extension of the scope from mineral oils without additives (type A lubricants) to cover, as type B lubricants, mineral oils containing additives, and lubricants wholly or partially cont
20、aining synthetic lubricants; b) the addition of viscosity grades VG100, VG150, VG220, VG320 and VG460; c) the reduction in acid number limit from0.1mg KOH per gram to0.05mg KOH per gram; and d) the introduction of optional requirements concerning the integrity of containers based on the requirements
21、 of Defence Standard91-60/1(OM-70). A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summa
22、ry of pages This document comprises a front cover, an inside front cover, pages i to iv, pages1to14, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on theinside front c
23、over.iv blankBS2626:1992 BSI 06-1999 1 1 Scope This British Standard specifies requirements for a range of10viscosity grades of two types of lubricants that are suitable for the lubrication of compressors for refrigerating systems operated with refrigerants as defined in BS4434. NOTE 1This British S
24、tandard does not specify requirements for the compatibility or miscibility of lubricants with refrigerants. However, it is essential that care is taken in the selection of a lubricant/refrigerant combination. NOTE 2Appendix A gives explanatory notes on refrigerant compressor lubricants and is for in
25、formation only. NOTE 3The titles of the publications referred to in this standard are listed on the inside back cover. 2 Sampling For the purposes of this British Standard all sampling shall be carried out in accordance with the relevant procedures and precautions described in BS3195-1. 3 Compositio
26、n The lubricants shall be one of the following types: a) type A lubricants, consisting of petroleum products free from additives; b) type B lubricants, consisting of either petroleum products containing additives, or wholly or partially of synthetic lubricants which may contain additives. NOTELubric
27、ants should not be mixed unless their compatibility has been established. 4 Appearance On visual inspection the lubricants shall be clear and free from water, suspended matter, dirt and sediment. 5 Physical and chemical characteristics When tested in accordance with the methods given in Table 1, the
28、 lubricants shall comply with the limiting requirements given in that table for the appropriate viscosity grade. Table 1 Physical and chemical requirements for refrigerant compressor lubricants Viscosity grade ISO VG Test method 15 22 32 46 68 100 150 220 320 460 Kinematic viscosity at40 C, incSt a
29、min. 13.5 19.8 28.8 41.4 61.2 90 135 198 288 414 BS2000-71 max. 16.5 24.2 35.2 50.6 74.8 110 165 242 352 506 Pour point, in C max. 39 39 30 30 24 21 21 21 21 21 BS2000-15 Flash point, by Pensky-Martens closed tester, in C min. 147 147 156 156 171 180 210 225 225 225 BS2000-34 Total acid number, in m
30、g KOH/g bc max. 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 BS2000-139 Free water content Type A No audible crackle in two out of three tests Appendix B Type B, in mg/kg max. 40 40 40 40 40 40 40 40 40 40 BS6725 Content of material insoluble in Refrigerant12 at 40 C,%(m/m) max. 0.3 0.3 0.3 0.3
31、 0.3 0.3 0.3 0.3 0.3 0.3 Appendix C Copper corrosion classification (3hat100 C) max. 1 1 1 1 1 1 1 1 1 1 BS2000-154 a 1 cSt=1 mm 2 /s=1 10 6 m 2 /s. b The provisions of clause8 do not apply as the limit is below the range provided for by the precision of the method. c There are certain formulated lu
32、bricants blended with additives that have a total acid number up to0.5mg KOH/g which are commercially available. Information should be sought from the manufacturer regarding their use.BS2626:1992 2 BSI 06-1999 6 Grade designation 6.1 General Lubricants shall be categorized by type and viscosity grad
33、e number in accordance with clause3 and6.2, respectively. 6.2 Viscosity grade designation The lubricants shall be designated according to their particular viscosity in accordance with the classification given in BS4231, i.e.a number corresponding to the midpoint of kinematic viscosity at40 C (e.g.VG
34、32). 7 Integrity of containers up to5lcontaining type A lubricant If specified by the purchaser, a batch of filled containers of up to5l capacity shall be free from leakage and the ingress of water when tested in accordance with Appendix D. 8 Precision and interpretation of results Most of the metho
35、ds given in Table 1 contain a statement of precision, i.e.the repeatability and reproducibility to be expected from them, but in cases of dispute the procedure described in BS4306, which uses precision data in the interpretation of the results, shall be used. 9 Packaging and marking The lubricant sh
36、all be supplied either in bulk, or in clean, sound and dry containers. (See clause7.) If the lubricant is supplied in containers, each container shall be legibly and durably marked with the following: a) the number and year of this British Standard, i.e.BS2626:1992 1) ; b) the type and viscosity gra
37、de designation, e.g.type A/VG32; c) the name or mark of the supplier or vendor and the batch or consignment number. 1) Marking BS2626:1992 on or in relation to a product represents a manufacturers declaration of conformity, i.e.a claim by or on behalf of the manufacturer that the product meets the r
38、equirements of the standard. The accuracy of the claim is therefore solely the responsibility of the person making the claim. Such a declaration is not to be confused with third party certification of conformity, which may also be desirable.BS2626:1992 BSI 06-1999 3 Appendix A Explanatory notes on r
39、efrigerant compressor lubricants A.1 General These notes have been included to give some general background information for users of this standard. They are intended to indicate the relevance of the specific properties and are not definitions of the terms. A.2 Viscosity The viscosity ranges from BS4
40、231 quoted in this British Standard have been chosen to cover the normal requirements of refrigerant compressors. However, it should be remembered that as a result of the high mutual solubilities between lubricant and halocarbon refrigerants the lubricating fluid in a compressor can no longer be tre
41、ated as a pure lubricant but rather as a lubricant/refrigerant solution that has properties which are markedly different from those of pure lubricant. The amount of refrigerant that dissolves in a lubricant depends on the prevailing pressure and temperature. Therefore the composition of the lubricat
42、ing fluid is different in different parts of the refrigeration system and varies as the operating parameters change. Amongst other characteristics, it is found that the highest viscosity does not occur at the lowest temperature. As the lubricant temperature reduces and approaches the prevailing refr
43、igerant saturation temperature, the quantity of dissolved refrigerant rapidly increases and the viscosity of the lubricating fluid tends towards the viscosity of pure refrigerant. This and other properties of a lubricant/refrigerant solution are illustrated in Figure 1. It is typical of the pressure
44、/temperature/viscosity charts that are usually obtainable from the lubricant suppliers, and which are different for each lubricant/refrigerant combination. A.3 Pour point The measurement of pour point, which is the lowest temperature at which a lubricant will flow under specified conditions, provide
45、s an indication of low-temperature properties. However, it may not accurately predict what will happen if a refrigerant is present in solution in the lubricant. Nevertheless, the pour point considered as an isolated property provides a good guide to the suitability of a lubricant for use in refriger
46、ated applications. Figure 1 Typical refrigerant/lubricant solubility/viscosity diagramBS2626:1992 4 BSI 06-1999 A.4 Flash point This test gives an indication of the flammability of the lubricant. It is the temperature at which sufficient lubricant has vaporized, when heated under controlled conditio
47、ns, such that the vapours will ignite when an ignition source is present. A.5 Total acid number The total acid number is important in two respects: a) it is a control parameter for the quality of the lubricant; b) lubricants containing more than the specified maximum acidity may adversely affect equ
48、ipment in service. A.6 Free water content Water may be slightly soluble in lubricants. Lubricants normally supplied for refrigerating systems may contain up to about40mg/l of dissolved water, depending on the relative humidity of the atmosphere. Lubricants containing this amount of water are regular
49、ly used satisfactorily, but if a lower water content is for some reason necessary, the lubricant should be specially dehydrated immediately before use. For type A lubricants the crackle test described in Appendix B normally detects any significant quantity of free water present. For type B lubricants the free water content is determined in accordance with BS6725. A.7 Content of material insoluble in Refrigerant12 2) Low temperatures may tend to cause the deposition of wax-like insoluble material from mixtures of refrigerants with minera
