AS 4670:2018 pdf free.Commercial propane and commercial butane for heating purposes.
NOTE 2 Residue on evaporation — This is a measurement of the concentration of materials present in the product which are substantially less volatile than propane and butane. The method specified in JLPGA-S-03 is applied at a temperature of 105°C.
NOTE 3 Total sulfur — It is acceptable to make relevant measurements at an earlier stage and to allow for the sulfur content of odorant to be added subsequently.
NOTE 4 Free water test — The free water test applies to commercial butane. The presence of water in a pressure hydrometer is obvious to the eye unless the product has been recently agitated. The sample complies if no free water is detectable by visual inspection. While no method has been specified for this test, visual inspection using the hydrometer specified in ISO 3993 is considered suitable.
NOTE 5 Odour level — LP Gas is odorized to provide an olfactory warning in the event of a release. The distinctive and unpleasant odour shall indicate to a person with a normal sense of smell the presence of LP Gas vapour at a concentration equal to (or less than) 20 % of the lower flammability limit (LFL) in air. To achieve this level of olfactory warning, the minimum concentration of ethyl mercaptan is 25 mg/kg in liquid propane, which typically equates to 11.5 mg/rn3 (MSC) or 4.4 ppm (v/v) in the vapour phase. The above concentration of ethyl mercaptan is deemed to comply. Other odorants that achieve an equivalent olfactory warning may be used. Sampling and testing at the point of custody transfer ultimately determines the initial dosing required in the liquid phase. Due to the possibility of olfactory fatigue, over-odorization is undesirable and shall be avoided. For further information on odour management, refer to AS/NZS 1596.
NOTE 6 Wobbe Index — For the purposes of this Standard, the Wobbe Index shall be calculated for a gas with the same composition (on a molar basis,) as the liquid product.
NOTE 7 Hydrocarbon composition, heating value and relative density of the vapour — Once the composition of the product is determined by gas chromatography to ISO 7941, the higher heating value, in MJ/m3, and relative density as a real gas are derived from ISO 6976.
NOTE 8 Appendix B — contains information related to the derivation of the specification contained in Table 1.
3.2 Precision and interpretation of test results
The methods of test specified in Table I contain a statement of the uncertainty of measurement, to be expected from them. In the case of a dispute, the dispute procedure described in ISO 4259-2, which uses precision data in the interpretation of test results, shall be used.AS 4670 pdf download.