ISO/PRF TS 6521-2

Lubricants, industrial oils and related products (Class L) -- Family D (Compressors)

Lubrifiants, huiles industrielles et produits connexes (Classe L) -- Famille D (Compresseurs)

General Information

• Status: Published
• ICS: 75.100 - Lubricants, industrial oils and related products
• 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

Standards Content (sample)

TECHNICAL ISO/TS
SPECIFICATION 6521-2
First edition
Lubricants, industrial oils and
related products (Class L) — Family D
(Compressors) —
Part 2:
Specifications of categories DAG, DAH
and DAJ (Lubricants for flooded rotary
air compressors)
Lubrifiants, huiles industrielles et produits connexes (Classe L) —
Famille D (Compresseurs) —
Partie 2: Spécifications des catégories DAH, DAI et DAJ (Lubrifiants
pour compresseurs d’air rotatifs à injection d’huile)
PROOF/ÉPREUVE
Reference number
ISO/TS 6521-2:2021(E)
ISO 2021
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ISO/TS 6521-2:2021(E)
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© ISO 2021

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ISO/TS 6521-2:2021(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 2

4 Sampling ........................................................................................................................................................................................................................ 2

5 General requirements ..................................................................................................................................................................................... 2

6 Specifications .......................................................................................................................................................................................................... 3

6.1 Specifications for ISO-L-DAG air compressor oils .................................................................................................... 3

6.2 Specifications for ISO-L-DAH air compressor oils .................................................................................................... 3

6.3 Specifications for ISO-L-DAJ air compressor oils ...................................................................................................... 3

Annex A (normative) Specifications tables .................................................................................................................................................... 4

Annex B (informative) Oxidation stability ...................................................................................................................................................... 7

Bibliography ................................................................................................................................................................................................................................ 8

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ISO/TS 6521-2:2021(E)
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 documents 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).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/ patents).

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.

A list of all parts in the ISO 6521 series can be found on the ISO website.

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.
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ISO/TS 6521-2:2021(E)
Introduction

Lubricants for compressors are used in various compressor designs. The lubricants for these

applications can vary in composition; from straight mineral oils to more complex blends, based on

mineral oils, synthetic oils (e.g. poly α-olefins, esters, poly-glycols), with appropriate antioxidants, rust

and corrosion inhibitors, extreme-pressure and anti-wear additives, possibly associated with detergent

and dispersing agents.

In flooded rotary air compressors, the compressor oil is injected with the air at the inlet port. The

oil serves as a coolant and limits the air temperature increase due to compression, allowing higher

compression rates in one stage. The oil is submitted to high oxidative stresses; the oil/air mixture is

submitted to temperatures up to 100 °C and even more. It is important to limit oil degradation.

In addition, oil has to be separated from the air at the exit of the compressor; this separation is achieved

using coalescing filters. Oil oxidation has the effect of disturbing the functioning of these filters,

leading to pressure drop increase and loss of the separating efficiency and, as a consequence, the oil

consumption increase. Oil oxidation stability is therefore of utmost importance.

Presently, there is no method making consensus to assess the oxidation stability of flooded rotary

compressor oils (see Annex B). Waiting for the development of a sound and accepted method, a technical

specification is proposed.
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TECHNICAL SPECIFICATION ISO/TS 6521-2:2021(E)
Lubricants, industrial oils and related products (Class L) —
Family D (Compressors) —
Part 2:
Specifications of categories DAG, DAH and DAJ (Lubricants
for flooded rotary air compressors)
1 Scope

This document specifies the minimum requirements for mineral or synthetic based lubricants, as

delivered, and intended for use in flooded rotary air compressors (vane and screw).

This document can be read in conjunction with ISO 6743-3.

NOTE For the purposes of this document, the term “% (m/m)” is used to represent the mass fraction of a

material.
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 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 2719, Determination of flash point — Pensky-Martens closed 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, Petroleum liquids — Manual sampling
ISO 3448, Industrial liquid lubricants — ISO viscosity classification

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 6247, Petroleum products — Determination of foaming characteristics of lubricating oils

ISO 6296, Petroleum products — Determination of water — Potentiometric Karl Fischer titration method

ISO 6614, Petroleum products — Determination of water separability of petroleum oils and synthetic fluids

ISO 6618, Petroleum products and lubricants — Determination of acid or base number — Colour-indicator

titration method
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ISO/TS 6521-2:2021(E)

ISO 6619, Petroleum products and lubricants — Neutralization number — Potentiometric titration method

ISO 6743-3, Lubricants, industrial oils and related products (class L) — Classification — Part 3: Family D

(Compressors)

ISO 7120, Petroleum products and lubricants — Petroleum oils and other fluids — Determination of rust-

preventing characteristics in the presence of water

ISO 12185, Crude petroleum and petroleum products — Determination of density — Oscillating U-tube

method

ISO 12937, Petroleum products — Determination of water — Coulometric Karl Fischer titration method

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 20764, Petroleum and related products — Preparation of a test portion of high-boiling liquids for the

determination of water content — Nitrogen purge method
3 Terms and definitions
No terms and definitions are listed in this document.

ISO and IEC maintain terminological 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 Sampling
Sampling of compressor oils for
...