ISO 3733:1999 pdf free.Petroleum products and bituminous materials — Determination of water — Distillation method.
ISO 3733 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.
ISO 3733 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
ISO 3170:1988, Petroleum liquids — Manual sampling.
ISO 3171:1988, Petroleum liquids — Automatic pipeline sampling.
ISO 3405: 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/I”)” 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 % (V/V) industrial grade xylene (mixed xylenes);
c) petroleum distillate, 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 0C.
4.2 Petroleum distillate solvent
A petroleum solvent, free of water, of which 5 % (V/n boils between 90 °C and 100 °C, and 90 % (V/V) distils below 210 C.
5 Apparatus
5.1 General
The apparatus comprises a glass or metal still, a heater, a reflux condenser, and a graduated glass trap. The still, trap and condenser shall be connected by any suitable method that produces a leak-proof joint. Preferred connections are ground joints for glass, and 0-rings for metal to glass. Typical assemblies of the glassware are shown in Figures 1 to 3 and the dimensions are given in Table 1 Any given testing apparatus will be deemed suitable, if accurate results are obtained using the methods described in 6.2 and 6.3. However, a straight water- cooled condenser with a length of 400 mm is recommended. The stills and traps shall be chosen to cover the range of materials and water contents expected. If the amount of water collected is likely to exceed 25 ml, a 25 ml trap fitted with a stopcock shall be used and the excess water shall be drained off into a graduated cylinder meeting the requirements of 6.2 and 6.3.ISO 3733:1999 pdf free download.