ISO 817-2014 pdf free download.Refrigerants一Designation and safety classification.
In the case where stereolsomers can exist, the opposed (Entgegen) isomer will be identified by the suffix (E) and the same side (Zusammen) isomer will be identified by the suffix (Z).
4.3 Ether-based refngerants shall be designated with the prefix “En (for “ethers) immediately preceding the number. Subclause 4.2 applies except for the following differences.
4.3.1 Two-carbon, dimethyl ethers (e.g. R-E125, CHF2-O-CF3) require no suffixes other than those specified in 4.2.9. as the presence of the “E” prefix provides an unambiguous description.
4.3.2 For straight chain, three carbon ethers, the carbon atoms shall be numbered with the number
1 assigned to the end carbon with the highest number of halogens, and the following carbon atoms are numbered sequentially as they appear on a straight chain. In the case where both end carbons contain the same number of (but different) halogen atoms, the number 1 shall be assigned to the end carbon having the largest number of bromine, then chlorine, then fluorine and then iodine atoms. For ethers with more than three carbons, the compound shall be assigned a number in the 600 series, miscellaneous organic compounds, as described in 4S
4.3.2.1 An additional integer identifying the first carbon to which the ether oxygen is attached shall be appended to the suffix letters (e.g. R-E236ea2, CHF2-O-CHF-CF3).
4.3.2.2 In the case of otherwise symmetric hydrocarbon structures, the ether oxygen shall be assigned to the carbon which has the leading position in the formula.
4.3.2.3 In those cases where only a single isomer exists for the hydrocarbon portion of the ether structure, such as CF3-O-CF2-CF3, the suffix letters described in 4.2.9. 4.2.10 and 4.2.11 shall be omitted. In this cited example, the correct designation shall be R-E218.
4.3.2.4 Structures containing two oxygen atoms, di-ethers, shall be designated with two suffix integers to designate the positions of the ether oxygen atoms.
4.3.3 For cyclic ethers carrying both the and “E” pre-fixes, the shall precede the “E7 as CE, to designate ‘cyclic ethers. For four-membered cyclic ethers, including three carbon and one ether oxygen atom, the basic number designations for the hydrocarbon atoms shall be constructed according to the current standard for hydrocarbon nomenclature, as described in 12.
4.4 Blends are assigned a refrigerant number in the 400 or 500 series.
4.4.1 Zeotropes shall be serially assigned an identifying number in the 400 series. In order to differentiate among the different zeotropes having the same components but in different proportions, an upper case letter (A, B, C, …) is added after the number.ISO 817 pdf download.