StandardDetails

This Gulf standard is applied only to asphaltic products derived from petroleum should not be applied to natural asphalts containing non-bituminous matter insoluble xylene. Materials, which by use of standard solvent are classified as positive, may be further tested to determine their degree of positiveness by means of their xylene equivalent. The xylene equivalent shall be the lowest percentage by volume of xylene in a solvent composed of xylene and standard naphtha or xylene and n-heptane, as specified, which product a negative spot for the material in the test. These shall be known as the naphtha xylene equivalent and heptane-xylene equivalent respectively. The percentage of xylene in the solvents shall be stated in even 5% increments. When neither xylene equivalent is specified, the standard naphtha only shall be used as solvent.