ASTM D7721-17

Standard Practice for Determining the Effect of Fluid Selection on Hydraulic System or Component Efficiency

SIGNIFICANCE AND USE
5.1 The purpose of a hydraulic fluid is to cool and lubricate fluid power components, as well as transmit power. This practice provides uniform guidelines for comparing fluids in terms of their power-transmitting abilities as reflected in their effect on hydraulic system or component efficiency. Standard test methods ISO 4409 and ISO 4392 provide specifications for evaluating the steady state performance of hydraulic pumps and motors but do not address technical requirements specific to hydraulic fluid testing.  
5.2 Differences in fluid performance may be relatively small. Consequently, it is essential that the necessary experimental controls are implemented to ensure consistency in operating conditions and duty cycle when comparing the energy efficiency of different hydraulic fluid formulations.  
5.3 Practical advantages of enhanced hydraulic system efficiency may include increased productivity (faster machine cycle time), reduced power consumption (electricity or fuel), and reduced environmental impact (lowered emissions).  
5.4 This practice implies no evaluation of hydraulic fluid quality other than its effect on hydraulic system efficiency.
SCOPE
1.1 This practice covers all hydraulic fluids.  
1.2 This practice is applicable to both laboratory and field evaluations.  
1.3 This practice provides guidelines for conducting hydraulic fluid evaluations. It does not prescribe a specific efficiency test methodology.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Historical
• Publication Date: 30-Apr-2017
• ICS: 75.120 - Hydraulic fluids
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.N0 - Hydraulic Fluids

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D7721 − 17
Standard Practice for
Determining the Effect of Fluid Selection on Hydraulic
1
System or Component Efficiency
This standard is issued under the fixed designation D7721; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
3
1. Scope* 2.2 ISO Standards:
ISO 4391 Hydraulic fluid power—Pumps, motors and inte-
1.1 This practice covers all hydraulic fluids.
gral transmissions—Parameter definitions and letter sym-
1.2 This practice is applicable to both laboratory and field
bols
evaluations.
ISO 4392 Hydraulic fluid power—Determination of charac-
teristics of motors
1.3 This practice provides guidelines for conducting hy-
draulic fluid evaluations. It does not prescribe a specific ISO 4409 Hydraulic fluid power—Positive displacement
pumps—Methods of testing and presenting basic steady
efficiency test methodology.
state performance
1.4 The values stated in SI units are to be regarded as
ISO 5598 Fluid power systems & components—Vocabulary
standard. No other units of measurement are included in this
ISO 8426 Hydraulic fluid power—Positive displacement
standard.
pumps and motors—Determination of derived capacity
1.5 This standard does not purport to address all of the
2.3 Other Standards:
safety concerns, if any, associated with its use. It is the 4
VDI 2198 Type Sheets for Industrial Trucks
responsibility of the user of this standard to establish appro-
3. Terminology
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
3.1 For additional definitions related to petroleum products
1.6 This international standard was developed in accor-
and lubricants, see Terminology D4175. For additional defini-
dance with internationally recognized principles on standard-
tions related to fluid power systems and components, see ISO
ization established in the Decision on Principles for the
5598.
Development of International Standards, Guides and Recom-
3.2 Definitions:
mendations issued by the World Trade Organization Technical
3.2.1 component, n—of a hydraulic system, an individual
Barriers to Trade (TBT) Committee.
unit, excluding piping, comprising one or more parts designed
to be a functional part of a fluid power system, for example,
2. Referenced Documents
cylinder, motor, valve, or filter.
2
2.1 ASTM Standards:
3.2.2 critical parts, n—those components used in the test
D4174 Practice for Cleaning, Flushing, and Purification of
that are known to affect test severity.
Petroleum Fluid Hydraulic Systems
3.2.3 cycle time, n—the amount of time it takes for a
D4175 Terminology Relating to Petroleum Products, Liquid
machine to perform a repetitive segment of an operation,
Fuels, and Lubricants
typically measured as the time it takes a machine to return to
the original position after completing a task.
1
3.2.4 effıciency, n—the ratio of actual work output of a
This practice is under the jurisdiction of ASTM Committee D02 on Petroleum
Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcom-
component or machine to the theoretical work output calcu-
mittee D02.N0 on Hydraulic Fluids.
lated from the measured input power.
Current edition approved May 1, 2017. Published June 2017. Originally
approved in 2011. Last previous edition approved in 2011 as D7721 – 11.
3
DOI:10.1520 ⁄D7721-17. Available from International Organization for Standardization (ISO), ISO
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier,
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Geneva, Switzerland, http://www.iso.org.
4
Standards volume information, refer to the standard’s Document Summary page on
AvailablefromVereinDeutscherIngenieure(VDI)(TheAssociationofGerman
the ASTM website.
Engineers), VDI-Platz 1, 40468 Düsseldorf, Germany, www.vdi.de.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D7721 − 17
3.2.5 energy consumption, n—the total energy content con- 3.3.3 effıciency improvement, n—a positive change in one or
sumed during a test in kWh; determined from electric power more parameters measured in a system or component that may
meter readings or calculated from the mass of fuel consumed be defined as a reduction in fuel consumption, electrical power
and the lower heating value of the fuel. draw, or temperature, an increase in work produced or flow
rate,
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D7721 − 11 D7721 − 17
Standard Practice for
Determining the Effect of Fluid Selection on Hydraulic
1
System or Component Efficiency
This standard is issued under the fixed designation D7721; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Scope*
1.1 This practice covers all hydraulic fluids.
1.2 This practice is applicable to both laboratory and field evaluations.
1.3 This practice gives overall provides guidelines for conducting science-based hydraulic fluid evaluations. It does not
prescribe a specific efficiency test methodology.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
D4174 Practice for Cleaning, Flushing, and Purification of Petroleum Fluid Hydraulic Systems
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
3
2.2 ISO Standards:
ISO 4391 Hydraulic fluid power—Pumps, motors and integral transmissions—parametertransmissions—Parameter definitions
and letter symbols
ISO 4392 Hydraulic fluid power—Determination of characteristics of motors
ISO 4409 Hydraulic fluid power—Positive displacement pumps—Methods of testing and presenting basic steady state
performance
ISO 5598 Fluid power systems & components - Vocabulary components—Vocabulary
ISO 8426 Hydraulic fluid power—Positive displacement pumps and motors—Determination of derived capacity
2.3 Other Standards:
4
VDI 2198 Type Sheets for Industrial Trucks
3. Terminology
3.1 For additional definitions related to petroleum products and lubricants, please refer to see Terminology D4175. For
additional definitions related to fluid power systems and components, please refer to see ISO 5598.
3.2 Definitions:
1
This practice is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.N0 on Hydraulic Fluids.
Current edition approved June 1, 2011May 1, 2017. Published September 2011June 2017. DOI:10.1520/D7721–11.Originally approved in 2011. Last previous edition
approved in 2011 as D7721 – 11. DOI:10.1520 ⁄D7721-17.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
Available from International Organization for Standardization (ISO), 1, ch. de la Voie-Creuse, CP 56, CH-1211 Geneva 20,ISO Central Secretariat, BIBC II, Chemin de
Blandonnet 8, CP 401, 1214 Vernier, Geneva, Switzerland, http://www.iso.org.
4
Available from Verein Deutscher Ingenieure (VDI) (The Association of German Engineers), VDI-Platz 1, 40468 Düsseldorf, Germany, www.vdi.de.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D7721 − 17
3.2.1 component, n—of a hydraulic system, an individual unit, excluding piping, comprising one or more parts designed to be
a functional part of a fluid power system, for example, cylinder, motor, valve, or filter.
3.2.2 critical parts, n—those components used in the test that are known to affect test severity.
3.2.3 cycle time, n—the amount of time it takes for a machine to perform a repetitive segment of an operation, typically
measured as the time it takes a machine to return to the original position after completing a task.
3.2.4 effıciency, n—the ratio of actual work output of a component or machine to the theoretical work output calculated from
the
...