ISO 8068:2024
Lubricants, industrial oils and related products (class L)-Family T (Turbines)-Specifications for lubricating oils for turbines

Standard No.

ISO 8068:2024

Release Date

2024

Published By

International Organization for Standardization (ISO)  IX  /  ISO

Latest

ISO 8068:2024

Introduction

Core Updates to ISO 8068:2024 Standard

The third edition of the standard mainly includes 5 technical innovations:

• Updates to environmental requirements for environmentally friendly products
• Added steam demulsibility requirements for steam/combined cycle single-shaft turbine oil grades
• Clarified the stage accuracy of filterability test (dry/wet method)
• Added new viscosity grades to TGCH and THCH categories
• Added EP (extreme pressure) classification to TGCH category

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Oil classification and performance matrix

Category	Base oil type	Typical viscosity grade	Flash point (℃)	Oxidation stability (h)
TSA/TGA	Mineral Oil (I-III+)	32/46/68	185	3,500
TGCH	Polyalphaolefin (IV)	32-100	200	4,000
THCE	Synthetic Esters (V)	32-100	175-205	To be negotiated

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Key indicators of environmentally friendly lubricants

For THCH/THCE type environmentally friendly oils, the standard requirements are:

1. Biodegradation rate ≥ 60% (ISO 14593/9439)
2. Acute aquatic toxicity LC50> 100mg/l (fish 96h test)
3. THCE must contain ≥25% bio-based carbon (ASTM D6866)

Implementation case: After the hydraulic system of a hydropower station was switched to THCE-46 oil, the natural degradation rate of the leaked oil reached 78% within 28 days, which met the operation requirements in ecologically sensitive areas.

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Solutions for special working conditions

TSD/TGDPhosphate ester flame retardant oils must meet the following requirements:

• Flash point ≥300℃ (ISO 2592)
• Manifold ignition test ≥700℃ (ISO 20823)
• Hydrolysis stability acid value increment ≤0.5mg KOH/g (EN 14833)

Suitable for high temperature scenarios such as aviation derivative gas turbines.

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Implementation Recommendations

Selection Process:

1. Confirm turbine type (steam/gas/hydraulic)
2. Evaluate operating temperature (normal/high temperature)
3. Check environmental regulations (especially water-sensitive areas)
4. Verify material compatibility (rubber seals, etc.)

Maintenance Points:Regularly monitor oxidation stability (RPVOT), moisture content (≤200ppm) and particle contamination (ISO 4406 Class 17/14).

ISO 8068:2024 Referenced Document

• DIN 51589-1 Determination of water separation ability of lubricating oils and low-flammability fluids after contact with steam
• EN 14832 Petroleum and related products - Determination of the oxidation stability and corrosivity of fire-resistant phosphate ester fluids
• EN 14833 Petroleum and related products - Determination of the hydrolytic stability of fire-resistant phosphate ester fluids
• EN 16807 Liquid petroleum products - Bio-lubricants - Criteria and requirements of bio-lubricants and bio-based lubricants
• EN 17181 Lubricants - Determination of aerobic biological degradation of fully formulated lubricants in an aqueous solution - Test method based on CO2-production
• ISO 12185 Crude petroleum, petroleum products and related products
• ISO 12937 Petroleum products - Determination of water - Coulometric Karl Fischer titration method
• ISO 13226 Rubber - Standard reference elastomers (SREs) for characterizing the effect of liquids on vulcanized rubbers
• ISO 13357-1 Petroleum products — Determination of the filterability of lubricating oils — Part 1: Procedure for oils in the presence of water*， 2025-04-01 Update
• ISO 13357-2 Petroleum products — Determination of the filterability of lubricating oils — Part 2: Procedure for dry oils*， 2025-04-02 Update
• ISO 14593 Water quality - Evaluation of ultimate aerobic biodegradability of organic compounds in aqueous medium - Method by analysis of inorganic carbon in sealed vessels (CO<(Index)2> headspace test)
• ISO 14635-1 Gears — FZG test procedures — Part 1: FZG test method A/8,3/90 for relative scuffing load-carrying capacity of oils
• ISO 14669 Water quality - Determination of acute lethal toxicity to marine copepods (Copepoda, Crustacea)
• ISO 14935 Petroleum and related products — Determination of wick flame persistence of fire-resistant fluids
• ISO 1817 Rubber, vulcanized or thermoplastic
• ISO 2049 Petroleum products - Determination of colour (ASTM scale)
• ISO 20764 Petroleum and related products - Preparation of a test portion of high-boiling liquids for the determination of water content - Nitrogen purge method
• ISO 20823 Petroleum and related products - Determination of the flammability characteristics of fluids in contact with hot surfaces - Manifold ignition test
• ISO 2160 Petroleum products - Corrosiveness to copper - Copper strip test
• ISO 2592 Determination of flash and fire points — Cleveland open cup method
• ISO 2909 Petroleum products - Calculation of viscosity index from kinematic viscosity
• ISO 3016 Petroleum and related products from natural or synthetic sources — Determination of pour point
• ISO 3104 Petroleum products — Transparent and opaque liquids — Determination of kinematic viscosity and calculation of dynamic viscosity
• ISO 3170 Hydrocarbon Liquids - Manual sampling*， 2025-06-01 Update
• ISO 3448 Industrial liquid lubricants - ISO vicosity classification; Technical Corrigendum 1
• ISO 3675 Crude petroleum and liquid petroleum products — Laboratory determination of density — Hydrometer method — Amendment 1
• ISO 4259-2 Petroleum and related products — Precision of measurement methods and results — Part 2: Interpretation and application of precision data in relation to methods of test AMENDMENT 1
• ISO 4263-1 Petroleum and related products - Determination of the ageing behaviour of inhibited oils and fluids; TOST test - Part 1: Procedure for mineral oils
• ISO 4263-3 Petroleum and related products - Determination of the ageing behaviour of inhibited oils and fluids using the TOST test - Part 3: Anhydrous procedure for synthetic hydraulic fluids
• ISO 4263-4 Petroleum and related products - Determination of the ageing behaviour of inhibited oils and fluids - TOST test - Part 4: Procedure for industrial gear oils
• ISO 4406 Hydraulic fluid power - Fluids - Method for coding the level of contamination by solid particles
• ISO 6247 Petroleum products - Determination of foaming characteristics of lubricating oils; Technical Corrigendum 1
• ISO 6296 Petroleum products - Determination of water - Potentiometric Karl Fischer titration method
• ISO 6341 Water quality - Determination of the inhibition of the mobility of Daphnia magna Straus (Cladocera, Crustacea) - Acute toxicity test
• ISO 6614 Petroleum products — Determination of water separability of petroleum oils and synthetic fluids — Amendment 1
• ISO 6618 Petroleum products and lubricants - Determination of acid or base number - Coulour-indicator titration method; Technical Corrigendum 1
• ISO 6743-5 Lubricants, industrial oils and related products (class L) - Classification - Part 5: Family T (Turbines)
• ISO 7120:1987 Petroleum products and lubricants; Petroleum oils and other fluids; Determination of rust-preventing characteristics in the presence of water
• ISO 7346-2 Water quality - Determination of the acute lethal toxicity of substances to a freshwater fish [Brachydanio rerio Hamilton-Buchanan (Teleostei, Cyprinidae)] - Part 2: Semi-static method
• ISO 760 Determination of water; Karl Fischer method (General method)
• ISO 8192 Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation
• ISO 9120 Petroleum and related products — Determination of air-release properties of steam turbine and other oils — Impinger method — Amendment 1
• ISO 9439 Water quality - Evaluation of ultimate aerobic biodegradability of organic compounds in aqueous medium - Carbon dioxide evolution test

ISO 8068:2024 history

• 2024 ISO 8068:2024 Lubricants, industrial oils and related products (class L)-Family T (Turbines)-Specifications for lubricating oils for turbines
• 2019 ISO 8068:2006/Amd 1:2019 Lubricants, industrial oils and related products (class L) — Family T (Turbines) — Specification for lubricating oils for turbines — Amendment 1: Filterability tests according to ISO 13357-1 and ISO 1
• 2006 ISO 8068:2006 Lubricants, industrial oils and related products (class L) - Family T (Turbines) - Specification for lubricating oils for turbines
• 1987 ISO 8068:1987 Petroleum products and lubricants; Petroleum lubricating oils for turbines (categories ISO-L-TSA and ISO-L-TGA); Specifications

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