BS ISO 4409:2019

What is ISO 4409 - Hydraulic fluid power about?

ISO 4409 discusses hydraulic fluid power. Hydraulic fluid power is generally used for low-pressure, high volume flow applications. ISO 4409 specifies methods for determining the performance and efficiency of hydraulic fluid power positive displacement pumps, motors, and integral transmissions. ISO 4409 applies to components having continuously rotating shafts. ISO 4409 specifies the requirements for test installations, test procedures under steady-state conditions and the presentation of test results.

Who is ISO 4409 - Hydraulic fluid power for?

ISO 4409 on hydraulic fluid power is useful for:

• Hydraulic power pumps manufacturers
• Hydraulic power motor manufacturers
• Hydraulic power plants
• Design engineers
• Quality control personnel

Why should you use ISO 4409 - Hydraulic fluid power?

In hydraulic fluid power systems, power is transmitted and controlled through a liquid under pressure within an enclosed circuit. Pumps are components that convert rotary mechanical power into hydraulic fluid power. Motors are components that convert hydraulic fluid power into rotary mechanical power. Integral transmissions (hydraulic drive units) are a combination of one or more hydraulic pumps and motors and appropriate controls forming a component. With very few exceptions, all hydraulic fluid power pumps and motors are of the positive-displacement type, i.e., they have internal sealing means that make them capable of maintaining a relatively constant ratio between rotational speed and fluid flow over wide pressure ranges. They generally use gears, vanes, or pistons. Non-positive displacement components, such as centrifugal or turbine types, are seldom associated with hydraulic fluid power systems.

ISO 4409 discusses hydraulic pumps and motors that are available either as “fixed-” or “variable-displacement” types. Fixed-displacement units have pre-selected internal geometries that maintain a relatively constant volume of liquid passing through the component per revolution of the component's shaft. Variable-displacement components have means for changing the internal geometries so that the volume of liquid passing through the component per revolution of the component's shaft can be changed. ISO 4409 is intended to unify testing methods for hydraulic fluid power positive displacement hydraulic pumps, motors, and integral transmissions to enable the performance of the different components to be compared. Using ISO 4409 you can specify methods for determining the performance and efficiency of hydraulic fluid power positive displacement pumps, motors, and integral transmissions.

What’s changed since the last update?

BS ISO 4409:2019 supersedes BS ISO 4409:2007. BS ISO 4409:2019 includes some technical changes with respect to BS ISO 4409:2007.

These include:

• The normative references in Clause 2 have been updated and revised to reflect the changes made to this document
• The terms and definitions in Clause 3 were updated and correctly referenced to agree with the existing ISO standards
• Clause 4 now correctly references the appropriate standard for symbols and units and the corresponding table has been revised to display symbols and units correctly
• The general description of Clause 5 was revised to include various types of conduits. A table with recommendations for the test fluid to be used is now provided, and the circuit diagrams have been revised for technical accuracy
• The suggested expression of results has been updated in Clause 6 to include meaningful values obtained from the data gathered with the tests