Measurement
Awaiting Valid Duty Parameters
Adjust the parameters on the left to compute live hydraulic values, ranges, and sizing verdicts.
Pump vibrating more than usual?
Vibration is the pump telling you something. Our engineers run vibration checks with repairs — diagnose, fix, verify.
Vibration diagnosis explained
The ISO 10816 zones
ISO 10816-1 defines four severity zones by machine class: A (new machine), B (acceptable long-term), C (not acceptable for continuous operation) and D (dangerous). A Class II pump — the 15–75 kW range covering most chemical pumps — crosses into C above about 2.8 mm/s and into D above 7.1 mm/s.
The checker maps your reading to the zone for your class, so a 3.2 mm/s reading on a 30 kW pump is a C-zone warning, while the same reading on a large 150 kW pump is still B.
Fault patterns
Vibration is a signature: 1×RPM dominance points to unbalance — impeller wear, coating loss, a bent shaft. 2×RPM points to misalignment or coupling wear. High-frequency broadband noise points to bearing damage. Random broadband plus noise at flow suggests cavitation. The checker uses your 1×/2× shares to shortlist the likely causes.
Take readings on both bearings, radial and axial, and trend them monthly — a jump of 25 % matters more than the absolute number.
Act on the zone
Zone B: monitor and trend. Zone C: plan the repair — balance, alignment, bearing replacement. Zone D: stop the pump and investigate before more damage. Teflow’s repair service covers balancing, alignment and bearing work with post-repair vibration verification — call +91 98251 62709.
Technical & Operational FAQs
Q1.What is ISO 10816?
The international standard for mechanical vibration severity of rotating machines, defining zone limits by machine class. ISO 10816-1 gives the four-class limits; ISO 10816-3 covers in-situ industrial machines. Successor ISO 20816-1 uses the same zone philosophy.
Q2.What vibration level is dangerous?
For Class II pumps (15–75 kW): above 7.1 mm/s is Zone D — dangerous, stop the pump. Above 2.8 mm/s is Zone C — not acceptable for continuous operation. The checker maps your reading to the exact zone for your class.
Q3.How do I measure pump vibration?
Use a vibration pen or accelerometer on the bearing housings, radial and axial. Record velocity in mm/s RMS — the ISO standard unit — at steady running conditions. Take several readings and trend them over time.
Q4.How do I tell unbalance from misalignment?
Unbalance shows dominantly at 1×RPM; misalignment shows a strong 2×RPM component (often with 1×). Compare the spectrum shares: 1×RPM above ~50 % suggests unbalance; significant 2×RPM suggests misalignment. The checker uses exactly these ratios.
Q5.Why does my VFD pump vibrate?
VFD-driven pumps can excite resonance at certain speeds, and low speeds reduce cooling and lubrication. Run a speed sweep to find resonant bands and skip them in the drive settings. Also check for electrical-side issues — motor current imbalance can pulse the torque.
Related Engineering Tools
Overhaul Cost Estimator
NPSH Available Calculator
Cavitation Guide
Pump Repair Service
Preventive Maintenance
Pump Consultancy
Need a custom hydraulic audit or specific duty curve verification? Call +91 98251 62709 or Request a Detailed Engineering Quote.