ASTM D1267 Test Method for Gage Vapor Pressure of Liquefied Petroleum (LP) Gases (LP-Gas Method)
6. Apparatus
6.1 Vapor Pressure Apparatus, constructed as illustrated in Fig. A1.1, and the various items of auxiliary equipment, are completely described in Annex A1.
6.2 The vapor chamber of Test Method D323, can be interchangeable with the upper chamber of this method. Similarly, the liquid chamber (two-opening type) of Test Method D323 is interchangeable with the B, 20 % lower chamber A1.1.4 of this method. Because of this interchangeability, the apparatus assembly of Test Method D323 shall pass, as a safety precaution, the hydrostatic test specified in A1.1.6 before using it in testing liquefied petroleum gas.
6.3 Water Bath, temperature controlled, of a size suitable for the vapor pressure apparatus. See A1.3.
6.4 Temperature Measuring Device, of verified accuracy and capable of monitoring the desired test temperature in the water bath in the range of 35 to 70°C to within +/- 0.1°C.
7. Sampling and Sample Handling
7.1 Samples shall be obtained and stored in accordance with Practice D1265 unless the test samples can be taken directly from the source of the material to be tested.
7.2 Any method of coupling the vapor pressure apparatus to the sample source may be employed. Tubing, 6 to 7 mm (1/4 in.) in diameter, of minimum length, of suitable-working pressure, and made of material corrosion-resistant to the products being sampled, is satisfactory for this purpose. A flexible tubing connection of a satisfactory type greatly facilitates the purging and sampling operations. The tubing should be a conducting material or constructed with a built-in ground connection to minimize the effect of static electricity.
8. Preparation of Apparatus
8.1 If the apparatus has been used for testing products other than the type of product to be tested, disassemble, clean thoroughly, and purge the parts in a stream of dry air.
8.2 Assemble the apparatus with the inlet valve of the lower chamber open, the straight-through valve between the two chambers open, the bleeder valve closed, and with the proper range pressure gage attached.
