ISO 18464:2025
(Main)Hydraulic fluid power — Design methodology for energy efficient systems
Hydraulic fluid power — Design methodology for energy efficient systems
This document specifies a design methodology for hydraulic systems that can be operated with the lowest possible energy consumption while maintaining the intended functionality of the stationary or mobile machinery in which they are installed. This document takes into account the duty cycles of the application. The definition of the duty cycles is not part of this document.
Transmissions hydrauliques — Méthodologie de conception de systèmes à haut rendement énergétique
General Information
Standards Content (Sample)
International
Standard
ISO 18464
First edition
Hydraulic fluid power —
2025-05
Design methodology for energy
efficient systems
Transmissions hydrauliques — Méthodologie de conception de
systèmes à haut rendement énergétique
Reference number
© ISO 2025
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms. 1
5 Design methodology . 2
5.1 General .2
5.2 Application based actuator design .3
5.3 Actuator dimensioning .4
5.4 Control design .4
5.5 Design of hydraulic power supplies .4
5.6 Design of hydraulic power distribution (piping) .4
5.7 Selection of the hydraulic fluid .5
5.8 Auxiliary components .5
5.9 Calculation method of required energy supply .5
5.10 Rating and comparison method of energy consumption.6
Annex A (informative) Example overview of energy demand of duty cycle and different
hydraulic system designs . 7
Annex B (informative) Recommendations for energy-efficient hydraulic piping . 8
Bibliography .10
iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
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This document was prepared by Technical Committee ISO/TC 131, Fluid power systems, Subcommittee SC 9,
Installations and systems.
Any feedback or questions on this document should be directed to the user’s national standards body. A
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iv
Introduction
As environmental impact is a common challenge for all products and as natural resources become scarce,
environmental performance criteria for hydraulic systems need to be defined and the use of these criteria
needs to be specified.
Based on relevant considerations, ISO 18464 is focused on environmental impacts related to the energy
consumed by hydraulic systems during operation and defines a design process for hydraulic systems
including energy consumption as a key criterion.
Energy consumption of hydraulic systems is primarily defined by the type of machine, e.g. lathes, injection
moulding machines and excavators, their duty cycles and the architecture of hydraulic systems.
Additionally, the level of energy consumption is a function of the requirements of the machine, duty cycle
and frequency of use by the operator. It is only when the machines are adapted for specific applications (e.g.
working cycle, control precision, level of automation) in an optimal manner, that energy efficient concepts
can have the most positive impact.
Typical applications for hydraulics in machines are
— clamping applications with high force,
— press applications with high force,
— motion, acceleration and braking of heavy loads,
— hydraulic mass compensation, and
— hydrostatic transmission.
v
International Standard ISO 18464:2025(en)
Hydraulic fluid power — Design methodology for energy
efficient systems
1 Scope
This document specifies a design methodology for hydraulic systems that can be operated with the lowest
possible energy consumption while maintaining the intended functionality of the stationary or mobile
machinery in which they are installed.
This document takes into account the duty cycles of the application. The definition of the duty cycles is not
part of this document.
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 5598, Fluid power systems and components — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5598 and the following apply.
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/
3.1
hydraulic system
arrangement of interconnected components including one or more prime movers, that generates, transmits,
controls and converts hydraulic fluid power
4 Symbols and abbreviated terms
The symbols used throughout this document are shown in Table 1.
Table 1 — List of symbols
Symbol Abbreviated term
d inner diameter of piping
amount of energy stored in hydraulic accumulators or other energy storage devices at the end of the
E
a,e
stabilised duty cycle, if energy storage devices are part of hydraulic systems
E amount of energy stored in hydraulic accumulators or other energy storage devices at the beginning of
a,s
the stabilised duty cycle, if energy storage devices are part of hydraulic systems
energy consumption of the hydraulic system over the considered duty cycle
E
c,in
E energy consumption for a specific duty cycle, i
c,in,i
TTabablele 1 1 ((ccoonnttiinnueuedd))
Symbol Abbreviated term
E energy which is fed back from the hydraulic system into the primary power source, e.g. the electrical
r
grid, or an electrical battery
E primary energy supply of the hydraulic system:
s,in
— primary energy supply for the prime mover of hydraulic systems (chemical, e.g. energy content
of fuel, electrical energy or a combination of these), for prime movers delivering energy in
parallel into others than the considered hydraulic systems and are controlled independently
of these hydraulic systems, see 5.1, second paragraph;
— primary energy supply for heating/cooling (heating or cooling power and coolant flow
power);
— primary energy supply for controls and auxiliary functions (i.e. valves, sensors, electronics,
filtration, etc.)
energy value of the hydraulic system design variant for mix of defined duty cycles
E
v
N number of duty cycles, i
i
recuperation power transient during duty cycle
Pt()
r
P primary power supply transient during duty cycle
s,in
Q flow rate
Re Reynolds number
t end time of duty cycle transient
dc,e
start time of duty cycle transient
t
dc,s
v flow velocity
ΔP power loss
Δp pressure loss
5 Design methodology
5.1 General
For the design of energy efficient hydraulic systems, typical duty cycles and functional requirements of
the machines hydraulic systems are designed for shall be used. The boundaries of hydraulic systems shall
include the prime movers. Nevertheless, for the efficiency comparison of hydraulic systems, the type of
prime movers (electrical, combustion or any others) is fixed for the application of this document.
NOTE Prime movers can have a significant effect on the overall efficiency of the machines for which the hydraulic
systems are designed for. This document is not intended for energy type selection of the prime mover.
If prime movers deliver energy in parallel into others than the considered hydraulic systems and are
controlled independently of these hydraulic systems, the energy fed into hydraulic systems may be
calculated by the torque and number of revolutions of the hydraulic pump shaft according to the rotational
speed and time distribution.
Figure 1 shows an example of a hydraulic system in its boundaries. More components can be part of hydraulic
systems.
Key
1 prime mover
2 hydraulic pump
3 hydraulic fluid power distribution and controls
4 hydraulic actuator, linear
5 hydraulic actuator, rotary
6 cooling/heating (fluid condition control)
7 accumulator
8 primary power supply
9 hydraulic actuator power output, mechanical power
10 thermal power
11 primary power supply for heating/cooling
12 primary power supply for controls and auxiliary functions
13 recuperated power
14 hydraulic system boundary
Figure 1 — Example of a hydraulic system in its boundaries
5.2 Application based actuator design
For linear drives (cylinders) design duty cycles shall be described by time transients of force and speed.
For rotary drives design duty cycles shall be described by time transients of torque and rotation speed.
5.3 Actuator dimensioning
Actuators shall be selected and dim
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