Pump-Unit R&D Acoustic Laboratories: Planning the Equipment Under Test and Circulation System Together

Planning an acoustic laboratory for liquid-pump R&D involves more than comparing room dimensions and sound-absorbing materials. A pump needs an appropriate fluid circuit to operate. Whether the drive is included in the measurement, and which pipes belong to the system under test, affect both the layout and the meaning of the results. Addressing these questions alongside the acoustic environment at the project-planning stage can reduce the need to find space for circulation equipment after the room has been selected.

Decide what the measurement results should represent

For a pump alone, the measurement excludes noise from the driver, transmission and piping. For a pump unit, it includes the driver, transmission, baseplates and auxiliary equipment supplied with the pump, but excludes noise from the piping system. If the objective is to assess the whole pumping system, including piping, that system boundary needs to be defined separately.[1] The same equipment may support different R&D tasks, but the three types of result are not interchangeable.

ISO 20361:2019 addresses airborne noise emission from pumps alone or pump units, including noise measurement and mounting and operating conditions. It does not characterize structure-borne sound or liquid-borne noise.[2] An airborne-noise laboratory therefore does not automatically provide every form of pump-noise assessment. Investigations of sound within the piping or structural vibration require separately planned measurement tasks and equipment.

Defining the boundary does not mean that every contribution can be separated at will. The project still needs to establish the applicable method and specific conditions using the full standard and its R&D objectives, rather than deciding after measurement which sounds to attribute to the pump.

Coordinate circulation equipment with the acoustic space

KSB's centrifugal-pump guidance explains that vibration of piping and the pump casing can radiate sound into the air, and that the operating point affects noise.[3] This supports comparing the equipment under test, test circuit and room together, rather than treating the circulation system as a service unrelated to measurement.

The measurement area should provide installation, measurement and maintenance space around the agreed test object and method. Supporting equipment required for the tests, such as liquid storage, flow regulation or temperature control, can be assessed for placement outside the measurement room. This must preserve the required operating and mounting conditions and keep every component intended for evaluation within the test boundary.

Moving supporting equipment outside the room does not remove the need to check its influence. Pipe penetrations, support connections and room ventilation should be coordinated by the acoustic, test-rig and building-services specialists. Room dimensions should also account for pump-unit access, installation work and maintenance. Space sufficient to position a sample may still be inadequate for pipe connections and changeovers.

For a laboratory intended to cover several pump types, representative products and operating conditions should be selected first to compare proposals. The team can then establish which tasks a shared circuit and its interfaces can support. A separate room is not necessarily needed for every pump type, but neither should one fixed circulation system be assumed suitable for all products.

Define the scope of the integrated solution

Lessent's work on acoustic test environments covers design, manufacture and engineering implementation.[4] Planning the acoustic space can provide a starting point for a pump R&D project, with layouts and interfaces agreed jointly with the customer and the specialists responsible for test rigs and circulation equipment. The suppliers of the pump test rig, circulation equipment, control system and data-acquisition system should be identified individually in the contract scope. An integrated approach should not imply that everything is included in one supply package.

Design reviews and handover verification should use agreed representative equipment and operating conditions to check measurement conditions with circulation equipment running. They should also establish whether the team can complete installation, operation, measurement and changeovers. The comparison then concerns a complete laboratory's ability to support R&D tasks, rather than only the acoustic performance of an empty room.

Sources

[1] ISO, ISO 20361:2019, publicly accessible introduction and terminology on the Online Browsing Platform.
https://www.iso.org/obp/ui?_escaped_fragment_=iso%3Astd%3Aiso%3A20361%3Aed-3%3Av1%3Aen

[2] ISO, ISO 20361:2019, Liquid pumps and pumps units — Noise test code — Grades 2 and 3 of accuracy. Published in 2019; reviewed and confirmed as current in 2025.
https://www.iso.org/standard/70650.html

[3] KSB, Noise in pumps and systems, Centrifugal Pump Lexicon.
https://www.ksb.com/en-global/centrifugal-pump-lexicon/article/noise-in-pumps-and-systems-1116102

[4] Lessent, Acoustic Laboratory Solutions.
https://www.lessent.com/labs