ISO 10050

Lubricants, industrial oils and related products (class L) — Family T (Turbines) — Specifications of triaryl phosphate ester turbine control fluids (category ISO-L-TCD)

This document specifies the characteristics of unused triaryl phosphate ester fluids for turbine governor controls and other hydraulic systems in electrical power stations. Fluids used in this application are classified under category TCD of ISO 6743-5.

Lubrifiants, huiles industrielles et produits connexes (classe L) — Famille T (Turbines) — Spécifications pour les fluides de régulation de turbines à base d'esters de triaryl phosphate (catégorie ISO-L-TCD)

Le présent document spécifie les caractéristiques des fluides neufs à base d’esters de triaryl phosphate utilisés pour la régulation des turbines et pour d’autres systèmes hydrauliques dans les centrales électriques. Les fluides utilisés pour ce domaine d’application sont classés sous la catégorie TCD de l’ISO 6743-5.

General Information

• Status: Not Published
• ICS: 75.120 - Hydraulic fluids
• Technical Committee: ISO/TC 28/SC 4 - Classifications and specifications
• Drafting Committee: ISO/TC 28/SC 4/WG 16 - Classifications and specifications of Industrial gear oils, turbine oils and compressor oils
• Current Stage: 6000 - International Standard under publication
• Completion Date: 25-Jun-2024

Relations

• Revises: ISO 10050:2005 - Lubricants, industrial oils and related products (class L) — Family T (Turbines) — Specifications of triaryl phosphate ester turbine control fluids (category ISO-L-TCD)
• Effective Date: 28-Oct-2023

Standards Content (Sample)

FINAL DRAFT
International
Standard
ISO/FDIS 10050
ISO/TC 28/SC 4
Lubricants, industrial oils and
Secretariat: AFNOR
related products (class L) — Family
Voting begins on:
T (Turbines) — Specifications of
2024-04-29
triaryl phosphate ester turbine
Voting terminates on:
control fluids (category ISO-L-TCD)
2024-06-24
Lubrifiants, huiles industrielles et produits connexes (classe
L) — Famille T (Turbines) — Spécifications pour les fluides
de régulation de turbines à base d'esters de triaryl phosphate
(catégorie ISO-L-TCD)
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
ISO/FDIS 10050:2024(en) © ISO 2024

FINAL DRAFT
ISO/FDIS 10050:2024(en)
International
Standard
ISO/FDIS 10050
ISO/TC 28/SC 4
Lubricants, industrial oils and
Secretariat: AFNOR
related products (class L) — Family
Voting begins on:
T (Turbines) — Specifications of
triaryl phosphate ester turbine
Voting terminates on:
control fluids (category ISO-L-TCD)
Lubrifiants, huiles industrielles et produits connexes (classe
L) — Famille T (Turbines) — Spécifications pour les fluides
de régulation de turbines à base d'esters de triaryl phosphate
(catégorie ISO-L-TCD)
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2024
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ISO/FDIS 10050:2024(en) © ISO 2024

ii
ISO/FDIS 10050:2024(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Composition . 2
5 Safety precautions. 3
6 Dyes . 3
7 Sampling . 3
8 Required characteristics . 3
9 Precision and interpretation of test results . 3
Bibliography . 6

iii
ISO/FDIS 10050:2024(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 28, Petroleum and related products, fuels and
lubricants from natural or synthetic sources, Subcommittee SC 4, Classifications and specifications.
This second edition cancels and replaces the first edition (ISO 10050:2005), which has been technically
revised.
The main changes are as follows:
— addition of precisions about the composition of the products;
— addition of safety precautions;
— updates of the specifications:
— the temperature for elastomer compatibility has been lowered to 60 °C to reflect the conditions of use;
— the corrosiveness to copper test has been added;
— the maintenance and use guide IEC 60978 has been replaced by ISO 11365.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
FINAL DRAFT International Standard ISO/FDIS 10050:2024(en)
Lubricants, industrial oils and related products (class L) —
Family T (Turbines) — Specifications of triaryl phosphate
ester turbine control fluids (category ISO-L-TCD)
WARNING — The handling and use of products as specified in this document can be hazardous, if
suitable precautions are not observed. This document does not purport to address all the safety
problems associated with its use. It is the responsibility of the users of this document to establish
appropriate safety and health practices and determine the applicability of regulatory limitations
prior to use.
1 Scope
This document specifies the characteristics of unused triaryl phosphate ester fluids for turbine governor
controls and other hydraulic systems in electrical power stations. Fluids used in this application are
classified under category TCD of ISO 6743-5.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 37, Rubber, vulcanized or thermoplastic — Determination of tensile stress-strain properties
ISO 48-2, Rubber, vulcanized or thermoplastic — Determination of hardness — Part 2: Hardness between 10
IRHD and 100 IRHD
ISO 760, Determination of water — Karl Fischer method (General method)
ISO 1817, Rubber, vulcanized or thermoplastic — Determination of the effect of liquids
ISO 2160, Petroleum products — Corrosiveness to copper — Copper strip test
ISO 2592, Petroleum and related products — Determination of flash and fire points — Cleveland open cup method
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, Petroleum liquids — Manual sampling
ISO 3675, Crude petroleum and liquid petroleum products — Laboratory determination of density —
Hydrometer method
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
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
ISO 6614, Petroleum products — Determination of water separability of petroleum oils and synthetic fluids
ISO 6619, Petroleum products and lubricants — Neutralization number — Potentiometric titration method

ISO/FDIS 10050:2024(en)
ISO 9120, Petroleum and related products — Determination of air-release properties of steam turbine and other
oils — Impinger method
ISO 12185, Crude petroleum, petroleum products and related products — Determination of density —
Laboratory density meter with an oscillating U-tube sensor
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 14935, Petroleum and related products — Determination of wick flame persistence of fire-resistant fluids
ISO 15597, Petroleum and related products — Determination of chlorine and bromine content — Wavelength-
dispersive X-ray fluorescence spectrometry
ISO 20823, Petroleum and related products — Determination of the flammability characteristics of fluids in
contact with hot surfaces — Manifold ignition test
IEC 60247, Insulating liquids — Measurement of relative permittivity, dielectric dissipation factor (tan δ) and
d.c. resistivity
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
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Composition
4.1 In general, phosphate esters are a class of organophosphorus compounds with the following chemical
structure:
O = P (OR)
where R is an alkyl, aryl or aryl substituted group. In control systems applications, only triaryl phosphate
fluids are used. R, in that case, is a substituted or an unsubstituted phenyl group.
4.2 When approved for use as governor fluids, substituents on the aromatic group are currently either
methyl (- CH ) or tertiary butyl (- C(CH ) ) groups.
3 3 3
4.3 If the substituents are methyl groups, the product is known as trixylyl phosphate (TXP). This material
is a substance of very high concern (SVHC) and its use is subject to authorization as it is included in Annex XIV
[9]
of the regulation for registration, evaluation, authorization and restriction of chemicals (REACH). Outside
the European Union, the fluid is widely used.
4.4 Additives can be incorporated to enhance oxidation stability, corrosion and rust protection, and to
reduce foaming. Use of viscosity modifiers is not allowed.

ISO/FDIS 10050:2024(en)
5 Safety precautions
5.1 Fires that can occur in turbine operations are caused by fluid or vapours contacting hot surfaces
or having impregnated the insulating materials around the hot pipes. The fluid that can leak, spill and be
absorbed into unprotected thermal insulation can provoke an exothermic reaction with resultant, potential,
rapid temperature increase. The ignition of the absorbed fluid can occur at temperatures below the fluid
auto-ignition temperature.
5.2 Phosphate esters fire-resistant fluids are difficult to ignite and
...

Style Definition
ISO/FDIS 10050:2024(E) .
Formatted: Font: 14 pt, Bold, French (Switzerland)
ISO /TC 28/SC 4/WG 16
Formatted: Left: 42.55 pt, Right: 42.55 pt, Top: 39.7
pt, Gutter: 0 pt, Section start: New page, Footer
Secretariat: AFNOR
distance from edge: 36 pt
Date: 2024-02-1404-15 Formatted
...
Formatted: zzCover large
Formatted
...
Formatted: Cover Title_A1
Lubricants, industrial oils and related products (class L) — Family T
(Turbines) — Specifications of triaryl phosphate ester turbine
control fluids (category ISO-L-TCD)
Lubrifiants, huiles industrielles et produits connexes (classe L) — Famille T (Turbines) — Spécifications pour
Formatted
...
les fluides de régulation de turbines à base d'esters de triarylphosphatetriaryl phosphate (catégorie ISO-L-TCD)
FDIS stage
ISO/FDIS 10050:2024(Een)
Formatted: Font: 11 pt, Bold
Formatted: Font: 11 pt, Bold
Formatted: HeaderCentered
Formatted: Font: 11 pt, Bold
Formatted: Adjust space between Latin and Asian text,
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication
may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, Adjust space between Asian text and numbers
or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO
Formatted: Default Paragraph Font
at the address below or ISO’s member body in the country of the requester.
Formatted: Default Paragraph Font
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
Formatted: French (Switzerland)
EmailE-mail: [e-mail]
Formatted: French (Switzerland)
Website: www.iso.orgwww.iso.org
Formatted: French (Switzerland)
Published in Switzerland
Formatted: FooterPageRomanNumber
 ISO 2024 – All rights reserved
ii
ii
ISO/FDIS 10050:2024(Een)
Formatted: Font: Bold
Formatted: HeaderCentered, Left
Formatted: Font: Bold
Contents Page
Formatted: Font: Bold
Foreword . iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Composition . 3
5 Safety precautions . 3
6 Dyes . 3
7 Sampling . 3
8 Required characteristics . 4
9 Precision and interpretation of test results . 4
Bibliography . 6

Foreword . iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 3
4 Composition . 3
5 Safety precautions . 3
6 Dyes . 4
7 Sampling . 4
8 Required characteristics . 4
9 Precision and interpretation of test results . 4
Bibliography . 7

Formatted: FooterPageRomanNumber, Left
 ISO 2024 – All rights reserved iii
iii
ISO/FDIS 10050:2024(Een)
Formatted: Font: 11 pt, Bold
Formatted: Font: 11 pt, Bold
Formatted: HeaderCentered
Foreword
Formatted: Font: 11 pt, Bold
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of
ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents.www.iso.org/patents. ISO shall not be held responsible for identifying any or all such
patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.htmlwww.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 28, Petroleum and related products, fuels and
lubricants from natural or synthetic sources, Subcommittee SC 4, Classifications and specifications.
This second edition cancels and replaces the first edition (ISO 10050:2005), which has been technically
revised.
The main changes are as follows:
— — addition of precisions about the composition of the products;
— — addition of safety precautions;
— — updates of the specifications:
— — the temperature for elastomer compatibility has been lowered to 60 °C to reflect the conditions
of use;
— — the corrosiveness to copper test has been added;
— — the maintenance and use guide IEC 60978 has been replaced by ISO 11365.
Formatted: FooterPageRomanNumber
 ISO 2024 – All rights reserved
iv
iv
ISO/FDIS 10050:2024(Een)
Formatted: Font: Bold
Formatted: HeaderCentered, Left
Formatted: Font: Bold
Any feedback or questions on this document should be directed to the user’s national standards body. A
Formatted: Font: Bold
complete listing of these bodies can be found at www.iso.org/members.html.
Field Code Changed
.
Formatted: English (United Kingdom)
Formatted: FooterPageRomanNumber, Left
 ISO 2024 – All rights reserved v
v
FINAL DRAFT INTERNATIONAL STANDARD
ISO/FDIS 10050:2024(E)
Formatted: Main Title 1, Adjust space between Latin
Lubricants, industrial oils and related products (class L) — Family T
and Asian text, Adjust space between Asian text and
(Turbines) — Specifications of triaryl phosphate ester turbine control
numbers
fluids (category ISO-L-TCD)
WARNING — The handling and use of products as specified in this document can be hazardous, if
suitable precautions are not observed. This document does not purport to address all of the safety
problems associated with its use. It is the responsibility of the users of this document to establish
appropriate safety and health practices and determine the applicability of regulatory limitations prior
to use.
1 Scope
This document specifies the characteristics of unused triaryl phosphate ester fluids for turbine governor
controls and other hydraulic systems in electrical power stations. Fluids used in this application are classified
under category TCD of ISO 6743-5.
Formatted
...
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
Formatted: Default Paragraph Font
Formatted: Adjust space between Latin and Asian text,
ISO 37, Rubber, vulcanized or thermoplastic — Determination of tensile stress-strain properties
Adjust space between Asian text and numbers, Tab
stops: Not at 19.85 pt + 39.7 pt + 59.55 pt + 79.4 pt
ISO 48--2, Rubber, vulcanized or thermoplastic — Determination of hardness — Part 2: Hardness between
+ 99.25 pt + 119.05 pt + 138.9 pt + 158.75 pt +
10 IRHD and 100 IRHD
178.6 pt + 198.45 pt
Formatted
ISO 760, Determination of water — Karl Fischer method (General method) .
Formatted
...
ISO 1817, Rubber, vulcanized or thermoplastic — Determination of the effect of liquids
Formatted
...
ISO 2160, Petroleum products — Corrosiveness to copper — Copper strip test
Formatted
...
Formatted
...
ISO 2592, Petroleum and related products — Determination of flash and fire points — Cleveland open cup
Formatted
method
...
Formatted
...
ISO 3016, Petroleum and related products from natural or synthetic sources — Determination of pour point
Formatted
...
ISO 3104, Petroleum products — Transparent and opaque liquids — Determination of kinematic viscosity Formatted
...
and calculation of dynamic viscosity
Formatted: Default Paragraph Font
Formatted: Adjust space between Latin and Asian text,
ISO 3170, Petroleum liquids — Manual sampling
Adjust space between Asian text and numbers, Tab
stops: Not at 19.85 pt + 39.7 pt + 59.55 pt + 79.4 pt
ISO 3448, Industrial liquid lubricants — ISO viscosity classification
+ 99.25 pt + 119.05 pt + 138.9 pt + 158.75 pt +
178.6 pt + 198.45 pt
ISO 3675, Crude petroleum and liquid petroleum products — Laboratory determination of density —
Formatted
Hydrometer method
...
Formatted: Left
 ISO 2024 – All rights reserved

ISO/FDIS 10050:2024(Een)
Formatted: Font: 11 pt, Bold
Formatted: HeaderCentered
Formatted: Font: 11 pt, Bold
ISO 4259--2, Petroleum and related products — Precision of measurement methods and results — Part 2:
Formatted: Font: 11 pt, Bold
Interpretation and application of precision data in relation to methods of test
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
ISO 6614, Petroleum products — Determination of water separability of petroleum oils and synthetic fluids
ISO 6619, Petroleum products and lubricants — Neutralization number — Potentiometric titration method
ISO 9120, Petroleum and related products — Determination of air-release properties of steam turbine and
other oils — Impinger method
ISO 12185, Crude petroleum, petroleum products and related products — Determination of density —
Laboratory density meter with an oscillating U-tube sensor
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 14935, Petroleum and related products — Determination of wick flame persistence of fire-resistant fluids
ISO 15597, Petroleum and related products — Determination of chlorine and bromine content —
Wavelength-dispersive X-ray fluorescence spectrometry
ISO 20823, Petroleum and related products — Determination of the flammability characteristics of fluids in
contact with hot surfaces — Manifold ignition test
IEC 60247, Insulating liquids — Measurement of relative permittivity, dielectric dissipation factor (tan δ) and
d.c. resistivity
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 fi
...