ISO 3735 pdf download.Crude petroleum and fuel oils — Determination of sediment — Extraction method
1 Scope
This International Standard specifies a method for the determination of sediment in crude petroleum and fuel oils by extraction with toluene. The precision applies to a range of sediment levels from 0,01 % (m / m) to 0,40 % (m / m), although higher levels may be determined. NOTE 1 If this International Standard is applied to crude petroleum samples containing significant amounts of salts, an overestimation of the sediment content may be obtained because a proportion of the inorganic salts may be trapped in the extraction thimble. This problem is generally not significant for crude petroleum samples containing less than 0,1 % (m / m) total salts. NOTE 2 For the purposes of this International Standard, the terms “% (m / m)” and “% (V / V)” are used to represent the mass and volume fractions of materials, respectively.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 1 773:1 997, Laboratory glassware — Narrow-necked boiling flasks. ISO 31 70:1 988, Petroleum liquids — Manual sampling. ISO 31 71 :1 988, Petroleum liquids — Automatic pipeline sampling . ISO 4793:1 980, Laboratory sintered (fritted) filters — Porosity grading, classification and designation. ISO 5272:1 979, Toluene for industrial use — Specifications .
3 Principle
A test portion, in a refractory thimble, is extracted with hot toluene until the residue reaches constant mass.
5 Apparatus
Usual laboratory apparatus and glassware, together with the following: 5.1 Extraction apparatus, as illustrated in figures 1 and 2, and consisting of the elements described in 5.1 .1 to 5.1 .6. 5.1.1 Extraction flask, consisting of a wide-necked conical (Erlenmeyer) flask of 1 litre capacity, conforming generally to the requirements of ISO 1 773, but with a minimum external neck diameter of 50 mm. 5.1.2 Condenser, in the form of a metal coil approximately 25 mm in diameter and 50 mm in length attached to, and with the ends projecting through, a lid of sufficient diameter to cover the neck of the flask as shown in figure 1 . The coil shall be made from stainless steel, tin, tin-plated copper or tin-plated brass tubing having an outside diameter of 5 mm to 8 mm and a wall thickness of approximately 1 ,5 mm. If constructed of tin-plated copper or brass, the tin coating shall have a minimum thickness of 0,075 mm. NOTE The exposed area of the coil for cooling purposes is approximately 1 1 5 cm 2 . 5.1.3 Extraction thimble, of a refractory porous material, pore size index P 1 6 according to ISO 4793, 25 mm in diameter by 70 mm in height, weighing not less than 1 5 g and not more than 1 7 g. The thimble shall be suspended from the condenser coil by means of a basket so that it hangs approximately mid-way between the surface of the extracting solvent (4.1 ) and the bottom of the condenser coil (see 5.1 .2). 5.1.4 Thimble basket, corrosion-resistant, made of platinum, stainless steel, nickel-chromium alloy, or similar material. It shall meet the design and dimension requirements of figure 2. 5.1.5 Water cup, for use when testing a sample with a water content in excess of 1 0 % (V / V) [see figure 1 b)]. The cup shall be made of glass, conical in shape, approximately 20 mm in diameter and 25 mm deep, having a capacity of approximately 3 ml. A glass hook shall be fused onto the rim on one side and shaped so that, when hung on the condenser, the cup hangs with its rim reasonably level.