ASTM D381-25 PDF

Full title and description

ASTM D381-25 — Standard Test Method for Gum Content in Fuels by Jet Evaporation. This test method covers procedures to determine existent (unwashed) and solvent‑washed gum in aviation fuels, motor gasolines, and other volatile distillates by evaporating a measured sample and assessing the nonvolatile residue (gum) remaining after specified extraction and drying steps.

Abstract

This standard specifies a laboratory jet‑evaporation procedure to measure gum content as an indicator of nonvolatile oxidation products, contamination, or handling-related residues in fuels. It includes provisions for determining the heptane‑insoluble portion of residues for non‑aviation fuels and notes safety considerations for hazardous reagents used in the method. The method is intended for quality control, specification verification and investigation of deposits in fuel systems.

General information

• Status: Active (current version designation D381-25; last updated April 9, 2025).
• Publication date: 2025 (current revision year 2025; ASTM record shows last update April 9, 2025).
• Publisher: ASTM International.
• ICS / categories: 75.160.20 (Liquid fuels).
• Edition / version: D381-25 (also shown as D0381-25 in ASTM product listings).
• Number of pages: 6.

Scope

The standard covers determination of existent gum in aviation turbine fuels and gum in motor gasoline and other volatile distillates in their finished form (including fuels with alcohol/ether oxygenates and deposit‑control additives). It provides procedures for solvent (heptane) extraction where required and includes measurement conventions in SI units. The method is intended to quantify oxidation and nonvolatile residues that may correlate with deposit tendencies, and it warns users to address chemical and safety hazards associated with the test.

Key topics and requirements

• Determination of existent (unwashed) gum and solvent‑washed gum in fuels using jet evaporation and controlled drying/evaporation conditions.
• Use of heptane extraction to remove nonvolatile oils/additives so that true deleterious gum can be measured.
• Specification of apparatus, sample sizes, evaporation technique, drying, and weighing procedures to obtain reproducible residue measurements.
• Reporting in SI units and attention to unit conventions for temperature and pressure.
• Safety requirements and warnings for hazardous materials referenced in the procedure (for example, mercury handling warnings where relevant in test equipment).

Typical use and users

Quality control and analytical laboratories in refineries, fuel distribution and aviation operations; engine and component manufacturers investigating deposit formation; regulatory and standards organizations assessing fuel conformance; research labs studying fuel oxidation and stability. The method is typically used where a simple, rapid indicator of nonvolatile residues (gum) is required for specification or troubleshooting.

Related standards

ASTM D381 is referenced by and used alongside other petroleum and fuel standards, for example aviation turbine fuel specifications and test methods such as ASTM D1655 (aviation turbine fuels) and specifications/tests for motor gasoline and ethanol blends (e.g., methods addressing density, water, sulfur, and other contaminants). The ASTM product listings and cross‑references identify D1655 and several fuel test methods that cite or are cited by D381.

Keywords

gum content; solvent‑washed gum; existent gum; jet evaporation; fuel residue; aviation turbine fuel; motor gasoline; heptane extraction; fuel stability; ASTM D381-25.

FAQ

Q: What is this standard?

A: ASTM D381-25 is the ASTM test method that specifies a jet‑evaporation procedure to measure gum (nonvolatile residue) in fuels.

Q: What does it cover?

A: It covers measurement of existent and solvent‑washed gum in aviation fuels and motor gasolines (and other volatile distillates), including provisions for heptane‑insoluble residue determination and SI unit reporting.

Q: Who typically uses it?

A: Fuel QC laboratories, refinery and distribution quality staff, aviation fuel handlers, engine/component test labs, and researchers investigating fuel stability and deposit formation.

Q: Is it current or superseded?

A: The D381-25 edition is the current active version (designation year 2025); ASTM records show the active standard with a last update recorded April 9, 2025. Users should check ASTM publication records for any later amendments.

Q: Is it part of a series?

A: Yes — D381 has prior editions (for example D381-22, D381-19, earlier revisions) and is maintained by ASTM Committee D02 (subcommittee D02.14). It is commonly referenced alongside other D02 petroleum/fuel test methods.

Q: What are the key keywords?

A: Gum content, solvent‑washed gum, existent gum, jet evaporation, heptane extraction, aviation fuel, motor gasoline, fuel residue.