ASTM D402 Method for Distillation of Cut-Back Asphaltic (Bituminous) Products
5. Apparatus
5.1 Distillation Flask, 500-mL side-arm, having the dimensions shown in Fig. 1.
5.2 Condenser, standard glass-jacketed, of nominal jacket length from 200 to 300 mm and overall tube length of 450 more or less 10 mm (see Fig. 3).
5.3 Adapter, heavy-wall (1-mm) glass, with reinforced top, having an angle of approximately 105°. The inside diameter at the large end shall be approximately 18 mm, and at the small end, not less than 5 mm. The lower surface of the adapter shall be on a smooth descending curve from the larger end to the smaller. The inside line of the outlet end shall be vertical, and the outlet shall be cut or ground (not fire-polished) at an angle of 45 more or less 5° to the inside line.
5.4 Shield, steel, lined with 3-mm fire proof insulation and fitted with transparent mica windows, of the form and dimensions shown in Fig. 2, used to protect the flask from air currents and to reduce radiation. The cover (top) shall be made in two parts of 6.4-mm fire proof insulation.
5.5 Shield and Flask Support - Two 15-cm2 sheets of 16-mesh Chromel wire gauze on a tripod or ring.
5.6 Heat Source
5.6.1 Adjustable Tirrill-type gas burner or equivalent.
5.6.2 An electric heater equipped with a transformer capable of controlling from 0 to 750 W. The shield and support shall be a refractory with an opening of 79 mm, with the upper surface beveled to 86 mm to accommodate the specified 500-mL flask. When the flask is placed on the refractory, there should be a distance of approximately 3 mm between the bottom of the flask and the heating elements.
5.7 Receiver - A standard 100-mL graduated cylinder conforming to dimensions of Specification E 133, or a 100-mL Crow receiver as shown in Fig. 4 of this test method.
NOTE 1 - Receivers of smaller capacity having 0.1-mL divisions may be used when low volumes of total distillate are expected and the added accuracy required.
5.8 Residue Container - A seamless metal container with slip on cover of 75 more or less 5 mm in diameter, and 55 more or less 5 mm in height.
5.9 Thermometer - ASTM High Distillation Thermometers having a range from -6 to 400°C (20 to 760°F) and conforming to the requirements for Thermometers 8C (8F) as prescribed in Specification E 1, or IP Thermometer 6C conforming to IP Specifications for Standard Thermometers, or an equivalent thermometric device that has been calibrated in accordance with Test Method E 220. ASTM 8C Thermometers shall be used for referee testing.
6. Sampling
6.1 Stir the sample thoroughly, warming if necessary, to ensure homogeneity before removal of a portion for analysis.
6.2 If sufficient water is present to cause foaming or bumping, dehydrate a sample of not less than 250 mL by heating in a distillation flask sufficiently large to prevent foaming over into the side arm. When foaming has ceased, stop the distillation. If any light oil has distilled over, separate and pour this back into the flask when the contents have cooled just sufficiently to prevent loss of volatile oil. Mix the contents of the flask thoroughly before removal for analysis. An alternative procedure is described in Test Method D370.
