GOST 33288-2015 PDF

Full title and description

GOST 33288-2015 — Residual fuel oils. Test for straight-run. Method for determination of xylene equivalent. This interstate (GOST) standard describes a laboratory spot-test procedure for determining the xylene equivalent of residual fuel oils (such as mazut and fuel bitumens) to assess straight-run character and solubility behavior using mixtures of xylene and n-heptane and paper-spot observation.

Abstract

The standard specifies a qualitative/quantitative spot-test method in which a sample of residual fuel is dissolved in mixtures of p-xylene (or xylene isomers) and normal heptane. Drops of cooled solutions are applied to filter paper and the presence or absence of a ring in the centre of the spot is used to determine the minimum volumetric fraction of xylene required to eliminate the ring — defined as the xylene equivalent. The method includes required apparatus, reagents, sample preparation, test procedure, interpretation and reporting rules. It is intended for quality control and classification of residual fuels with respect to straight-run (direct-distillate) characteristics.

General information

• Status: Active (in force).
• Publication date: Technical designation year 2015; introduced into force on January 1, 2017.
• Publisher: Interstate standard (GOST); official publication issued in Moscow by Standartinform on behalf of the developer committee.
• ICS / categories: 75.160.20 (Extraction and refining of petroleum products; petroleum fuels and lubricants).
• Edition / version: First edition, GOST 33288-2015 (adopted 2015, effective January 1, 2017).
• Number of pages: 7 (short-method standard).

Scope

GOST 33288-2015 establishes the laboratory method to determine the xylene equivalent of residual fuel oils (mazuts and bitumens). The method is intended to characterise the solvency/straight-run nature of heavy fuel fractions by determining the minimum volumetric concentration of xylene in a xylene–n‑heptane solvent mixture that prevents formation of a central “ring” in a paper spot. It is applicable to routine quality control, product specification checks and research where solvent solubility character of residual fuels is relevant.

Key topics and requirements

• Definition of “xylene equivalent” as the minimum volumetric fraction of xylene in a xylene–n‑heptane solvent that produces no central ring in a paper spot of the dissolved fuel sample.
• Required reagents and materials: p-xylene (or xylene isomer mixture), normal n‑heptane of specified purity, toluene (for cleaning, when needed), specified filter papers (e.g., Whatman types), glass slides and standard glassware.
• Apparatus and conditions: Erlenmeyer flasks with reflux condensers, boiling water bath, pipettes, drying oven and glass slides for secondary checks.
• Sample preparation: representative sampling (references to GOST sampling standards), controlled heating if necessary to obtain a pourable sample, and precise sample masses for dissolution.
• Test procedure: prepare a series of xylene–heptane mixtures (example concentrations include 0%, 45% and 90% v/v as starting points), dissolve measured amounts of sample under reflux with periodic agitation, cool, apply droplets to filter paper, dry and inspect spots; repeat with incremental changes in xylene content (typically 5% steps) until two adjacent concentrations differing by 5% show absence of a central ring.
• Result interpretation and reporting: report the xylene equivalent (expressed as volumetric % xylene) and note any observations about insoluble residues or ambiguous rings; secondary glass-slide procedure described for borderline cases.
• Precision and repeatability: the procedure includes steps to ensure reproducibility (specified sample masses, heating/shaking regimen, drying time and ambient temperature limits for examination).

Typical use and users

Primary users are chemical and physical testing laboratories at oil refineries, fuel production and blending facilities, commercial quality-control laboratories, standards and regulatory bodies, and research organisations dealing with heavy petroleum fractions. Typical uses include incoming/outgoing fuel inspection, classification of residual fuels (mazut, fuel bitumens), monitoring blending and solvent-remediation processes, and research into solvency and stability of heavy fuels.

Related standards

GOST 33288-2015 cross-references and uses materials specified in other GOSTs commonly cited in fuel testing, including standards for reagents and sampling such as GOST 25828 (n‑heptane), GOST 9410 (xylene), GOST 14710 or GOST 5789 (toluene), and sampling standards like GOST 2517 and GOST 31873. It is produced under the work of the interstate technical committee MTK 31 (petroleum fuels and lubricants) and complements other GOST-methods for residual fuel characterization and physical/chemical testing.

Keywords

residual fuel oils, mazut, fuel bitumen, xylene equivalent, straight-run test, solvent spot test, xylene–heptane mixture, fuel quality control, petrochemical laboratory, GOST 33288-2015

FAQ

Q: What is this standard?

A: GOST 33288-2015 is a GOST (interstate) standard that specifies a laboratory method for determining the xylene equivalent of residual fuel oils to assess straight-run/solvency characteristics.

Q: What does it cover?

A: It covers test principle, reagents and apparatus, sample preparation, stepwise test procedure using xylene–n‑heptane solvent mixtures, interpretation of paper-spot results, and reporting of the xylene equivalent for residual fuels.

Q: Who typically uses it?

A: Oil refinery and fuel testing laboratories, commercial QC labs, fuel producers and blenders, regulatory laboratories and research institutions working with heavy fuel fractions.

Q: Is it current or superseded?

A: As published, GOST 33288-2015 is in force and was introduced on January 1, 2017. It is listed as active (not superseded) in standard catalogues; users should verify with their national/regional standards bodies for any later amendments or replacements before relying on the procedure for regulatory compliance.

Q: Is it part of a series?

A: The standard was developed under the interstate technical committee MTK 31 (petroleum fuels and lubricants) and complements other GOST methods for testing fuel properties; it is one of several GOSTs that address residual fuel testing and reagent specifications.

Q: What are the key keywords?

A: Residual fuel oils, xylene equivalent, straight-run, solvent spot test, mazut, bitumen, xylene–heptane, fuel quality control.