ISO 3733:1999 pdf download.Petroleum products and bituminous materials一Determination of water一Distillation method
1 Scope
This International Standard specifies a method for determination of water up to 25 % in petroleum products, bitumens, tars and products derived from these materials, excluding emulsions, by the distillation method. The specific products considered during the development of this test method are listed in Table 3.
This International Standard may be used to determine water content in excess of 25 %. However, no precision data has been determined at levels greater than 25 %. Volatile water-soluble material, if present, is measured as water.
NOTE 1 A knowledge of the water content of petroleum products is important in the refining, purchase, sale and transfer of products.
NOTE 2 The amount of water determined by this method can be used to correct the volume involved in the custody transfer of product.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards.
ISO 3170:1988, Petroleum liquids — Manual sampling.
ISO 3171:1988, Petroleum liquids — Automatic pipeline sampling.
ISO 3405:_i), Petroleum products — Determination of distillation characteristics at atmospheric pressure.
3 Principle
The test material is heated under reflux with a water-immiscible solvent, which co-distills with the water in the sample. Condensed solvent and water are continuously separated in a trap, the water settling in the graduated section of the trap and the solvent returning to the still.
4 Reagents
NOTE For the purposes of this International Standard, the expression“% (V/V)" is used to represent the volume fraction of a material.
A solvent-carrier liquid appropriate to the materials being tested (see Table 3) shall be used.
4.1 Aromatic solvent
The following aromatic solvents, free of water (0,02 % maximum) are suitable:
a) industrial grade xylene (mixed xylenes);
b) a blend of 20 % (V/V) industrial grade toluene and 80 % (VV) industrial grade xylene (mixed xylenes);
c) petroleum disillate, yielding not more than 5 % (V/V) distillates at 125 °C and not less than 20 % (V/V) at 160 °C when tested in accordance with ISO 3405 and with a density not lower than 855 kg/m3 at 15 °C.
4.2 Petroleum distillate solvent
A petroleum solvent, free of water, of which 5 % (V/V) boils between 90 °C and 100 °C, and 90 % (V/V) distis below 210 °C.
4.3 Paraffinic solvents
The following paraffinic solvents, free of water, are suitable:
a) light petroleum with a biling range of 100 °C to 120。C;
b) 2,2,4-trimethylpentane (iso octane) of 95 % purity or better.ISO 3733 pdf download.