Pump test stands
Test stands for pumps, fans and compressors: rotating performance mapping, reliability and NVH. Component test rigs cover bearings, gears, shafts and pumps.
Test standsFor pump manufacturers and repair shops
Balancing machines for pump impellers and rotating assemblies, from small single-stage designs to large multi-stage units, for pump manufacturers and repair shops. Vertical machines suit single-plane impellers and horizontal machines take two-plane and multistage rotors, with manual or automatic correction. Installation and operator training included as standard, with support in the UK and USA.

Pump impeller balancing
Every pump impeller.
Impeller balancers handle the full range of pump impellers.
Correction
Milled, ground or welded.
Many impellers are still corrected manually. Automated systems are available where throughput, repeatability or precision demand it.
| Impeller type | Usual correction |
|---|---|
| Closed or semi-closed | Milling in automatic systems; manual grinding in lower-volume or repair settings |
| Open | Grinding, or welding weights directly to the blades |
Machine type
Two layouts, two jobs.
A disc-type rotor with a bore, such as a pump impeller, will typically go onto a vertical balancing machine. Vertical machines are often better suited to higher volumes and automated correction, including integrated drilling or milling.
A horizontal machine gives a repair or jobbing shop the flexibility to handle a wide variety of components, pumps included.
Mandrels on horizontal machines; solid adapters or automatic chucks on vertical machines, for secure and repeatable mounting.
Read more: vertical balancing machines · horizontal balancing machines.
Beyond the impeller
Motors, shafts and testing.
Electric motor balancing machines for individual rotors and complete motor assemblies, from manual systems to fully automated, robot-fed machines.
Electric motor machines →Straightening machines for any shaft, including splined, stepped and threaded shafts, with PLC-controlled measurement and correction.
Straightening machines →Test stands for pumps, fans and compressors: rotating performance mapping, reliability and NVH. Component test rigs cover bearings, gears, shafts and pumps.
Test stands →Balance grades
Tolerance worked out for you.
Every machine includes a built-in ISO calculator that works out tolerance levels to ISO balancing standards, with data logging and a printed balance certificate for each part.
Pump impellers are typically balanced to ISO 21940-11 grade G6.3, or G2.5 for higher speeds. Our machines' minimum achievable residual unbalance is well inside both.
Why Balance & Test
Service that delivers.
Industry leading on new machines.
Installation and operator training included as standard.
Plus remote support and local service teams.
Calibration validated against ISO 21940-21, with a full calibration certificate.
Balancing machines are built to CE, UL or CSA standards, to suit your market.
We service other manufacturers' machines as well as our own.
FAQ
As a rule of thumb, an impeller whose diameter is six or more times its width is balanced in one plane, usually on a vertical machine. Wider impellers, two-plane work and multistage rotors go on a horizontal machine.
Yes. Closed and semi-closed impellers are commonly corrected by milling in automatic systems.
Yes. Manual grinding is the usual correction method in lower-volume and repair settings, and a horizontal machine handles the widest variety of parts.
Pump impellers are typically balanced to ISO 21940-11 grade G6.3, or G2.5 for higher speeds. Our machines' minimum achievable residual unbalance is well inside both. Every machine includes a built-in ISO calculator that works out the tolerance for you, with data logging and a printed balance certificate for each part.
Yes. Installation and operator training are included as standard, with a warranty of up to 3 years. After handover you have remote support and local service teams, from our head office and service center in Bristol, UK, our service and support office in Ann Arbor, Michigan, and our teams in Spain and Germany.
Ready to balance?
Send us the impeller drawing and the grade you need to meet, and we'll recommend the machine.