ASTM D7671-21

4.1Crude petroleum contains sulfur compounds, most of which are removed during refining. However, of the sulfur compounds remaining in the petroleum product, some can have a corroding action on various metals and this corrosivity is not related to the total sulfur content. In addition, fuels can become contaminated by corrosive sulfur compounds during storage and distribution. The corrosive effect can vary according to the chemical types of sulfur compounds present.

4.2The silver strip corrosion test is designed to assess the relative degree of corrosivity of a petroleum product towards silver and silver alloys.

4.3Reactive sulfur compounds present in automotive spark-ignition engine fuels under some circumstances can corrode or tarnish silver alloy fuel gauge in-tank sender units (and silver-plated bearings in some 2-stroke cycle engines). To minimize or prevent the failure of silver alloy in-tank sender units by corrosion or tarnish, Specification D4814 requires that fuels shall pass the silver strip corrosion test.

1.1This test method covers the determination of the corrosiveness to silver by automotive spark-ignition engine fuel, as defined by Specification D4814, or similar specifications in other jurisdictions, having a vapor pressure no greater than 124kPa (18psi) at 37.8C (100F), by one of two procedures. Procedure A involves the use of a pressure vessel, whereas Procedure B involves the use of a vented test tube.

1.2The result of the test is based on a visual rating that is classified as an integer in the range from 0 to 4 as defined in Table 1.

1.3WarningMercury has been designated by many regulatory agencies as a hazardous substance that can cause serious medical issues. Mercury, or its vapor, has been demonstrated to be hazardous to health and corrosive to materials. Use caution when handling mercury and mercury-containing products. See the applicable product Safety Data Sheet (SDS) for additional information. The potential exists that selling mercury or mercury-containing products, or both, is prohibited by local or national law. Users must determine legality of sales in their location.

1.4The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.

1.5This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.6This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.