ASTM D4740-24 PDF

Full title and description

Standard Test Method for Cleanliness and Compatibility of Residual Fuels by Spot Test — a laboratory spot-test procedure (manual and automated variants) used to assess the cleanliness (presence of suspended solids) of residual fuel oils and to evaluate compatibility between a residual fuel and a blend stock by comparison of fuel “spots” against reference examples.

Abstract

This standard defines procedures to produce and evaluate spot-test images from residual fuel samples to determine cleanliness and compatibility. It applies primarily to residual fuel oils (up to about 50 cSt at 100 °C), describes both manual and automated protocols, and uses reference spot patterns (an adjunct) to rate cleanliness/compatibility on a multi-level scale.

General information

• Status: Current / Active standard (D4740-24).
• Publication date: 1 November 2024 (designation D4740-24).
• Publisher: ASTM International (ASTM).
• ICS / categories: 75.160.20 (Liquid fuels).
• Edition / version: ASTM D4740-24 (revises D4740-20).
• Number of pages: 8 pages.

Scope

The standard covers separate procedures for (a) determining the cleanliness of residual fuel oil (visual/spot rating for suspended solids and deposits) and (b) assessing the compatibility of a residual fuel with a proposed blend stock by producing and comparing heated spots on test paper to reference spot images. It is applicable to residual fuel oils with viscosities up to approximately 50 cSt at 100 °C and provides both manual and automated test protocols; it explicitly notes limitations for certain heavy distillates that may leave wax-like sediments.

Key topics and requirements

• Preparation and application of fuel samples to the test medium (spotting onto specified paper).
• Controlled heating/oven step to develop the spot image (reference adjunct shows oven heating and one-hour development examples used for comparison).
• Manual and automated spot-imaging protocols and procedures for visual or instrument-assisted comparison.
• Reference spot rating system (multi-level scale, typically rated No. 1 through No. 5) and use of an adjunct reference sheet for cleanliness/compatibility classification.
• Applicability limits (residual fuel oils up to ~50 cSt at 100 °C) and notes on fuel types where the method has not been evaluated.

Typical use and users

Used by petroleum laboratories, refinery QA/QC teams, fuel blenders, bunker fuel suppliers, marine fuel analysts, independent testing laboratories, and port/terminal quality control staff to screen residual fuels for particulate contamination and to check blend compatibility before mixing or bunkering operations.

Related standards

D4740-24 revises ASTM D4740-20 and is published alongside an adjunct reference sheet (ASTM ADJD474023) that supplies photographic reference spots. It is commonly used in the suite of ASTM petroleum/fuel test methods (examples: D4176 visual/free-water and particulate checks, D2068 filter blocking tendency, and other D-series fuel quality procedures) for complementary fuel quality assessments.

Keywords

cleanliness; compatibility; residual fuel; spot test; spot rating; adjunct; reference spot; fuel compatibility; fuel cleanliness; ICS 75.160.20.

FAQ

Q: What is this standard?

A: ASTM D4740-24 is the Standard Test Method for Cleanliness and Compatibility of Residual Fuels by Spot Test, a laboratory procedure for producing and evaluating fuel “spots” to determine suspended solids/cleanliness and blend compatibility.

Q: What does it cover?

A: It covers sample application, controlled heating to develop test spots, visual/instrument comparison against reference spots, and a rating system to classify cleanliness and compatibility for residual fuel oils (noted applicability up to ~50 cSt at 100 °C).

Q: Who typically uses it?

A: Refinery and laboratory analysts, fuel blenders, bunker suppliers, marine fuel inspectors, port/terminal quality personnel, and third-party test labs performing fuel acceptance and compatibility screening.

Q: Is it current or superseded?

A: Current — the active designation is ASTM D4740-24, published 1 November 2024; it replaces the prior D4740-20 edition.

Q: Is it part of a series?

A: Yes — it is part of the ASTM D-series petroleum and liquid fuel test methods and has an associated adjunct (ASTM ADJD474023) that provides the reference spot images used for the method. It is used alongside other fuel test standards for comprehensive fuel quality programs.

Q: What are the key keywords?

A: Cleanliness; compatibility; residual fuel; spot test; spot rating; adjunct; fuel quality; ICS 75.160.20.