Vibration Consulting

Rotating Machinery Vibration Consultants — Pumps, Compressors, Turbines, Fans

We diagnose and fix vibration at its source — combining on-site measurement, modal/operational analysis, rotordynamics and structural dynamics to design practical control and isolation. Remedies are validated against ISO 20816/7919 and the relevant API standards.

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Evidence-led diagnostics (orbits, Bode/Nyquist, run-up/coast-down, ODS/modal), engineered remedies, and clear compliance reporting.

Overview

Machines We Cover

Pumps • Compressors • Turbines & Generators • Fans & Blowers • Motors & Gearboxes • Coupled trains on skids, frames and foundations.

Rotating machinery issues are often structure-coupled — see Modal Testing and Structural Dynamics for underlying methods.

Typical Symptoms

  • Elevated 1×/2× vibration, trips near critical speed, hot bearings/seals.
  • Resonance of frames/baseplates/foundations; piping vibration / acoustic excitation.
  • Pumps: cavitation, off-BEP. Compressors: surge/pulsation. Fans: stall.
  • Looseness, misalignment, unbalance, rubs, soft foot, gear mesh issues.

Machines & Issues at a Glance

Machine Typical Issues Our Focus
Pumps Off-BEP, cavitation, high 1×/2× Balance, stiffness/isolation, BEP targeting
Compressors Surge/pulsation, frame resonance ODS/modal, frame tuning, API compliance
Fans & Blowers Stall, duct effects, structural hotspots Bracing/tuning, balance, ISO 14694
Motors & Gearboxes Electromech vibration, mesh, looseness Laser alignment, balance, root-cause plots

Many rotating issues are structure-coupled—see Modal Testing and Structural Dynamics.

Diagnostics, Fix & Validation

Engineered remedies

  • In-situ balancing (ISO 1940/21940) and laser alignment.
  • Structural tuning: stiffening, damping, isolation, mass redistribution.
  • Process fixes: operating bands, BEP targeting, surge avoidance.

Validation & compliance

  • Pre/post testing to ISO 20816/7919 and relevant API.
  • Acceptance bands, plots & as-built details.
  • See standards & compliance.

Case Study: Achieving API 619 Vibration Compliance

Client: Roots Systems • Location: Wales • Standard: API 619

Problem

The assembled station failed the permitted vibration limits of API 619. Trial wooden packing under the pump–motor frame reduced vibration only marginally; vibration increased as differential pressure rose from 0.2 bar toward the 2 bar operating target.

Investigation & Findings

  • Measured blower pulsation at 47.2 Hz; bearing vibration above limits.
  • Critical speeds ruled out; the frame natural frequency was too close to 47.2 Hz (resonance).
  • FEA (Ansys) and Experimental Modal Testing confirmed the mode and frequency proximity.

Solution

Fast-track frame stiffening to shift the natural frequency away from 47.2 Hz, eliminating resonance. Model Updating aligned the FE model to the modified structure.

Results

  • Post-mod FRFs showed no peaks near 47.2 Hz; mode shifted to a non-critical range.
  • API 619 audit passed: bearing vibration within permitted limits.
  • Station ready for efficient operation at 2 bar differential pressure.

Read the full API 619 case study »

FAQs

What vibration limits do you use?

Acceptance bands set to ISO 20816/7919 for machine class/foundation and the relevant API (e.g. 610/617/618/619).

Do you balance and align on site?

Yes — single/two-plane in-situ balancing to ISO 1940/21940 and laser alignment to OEM/API tolerances, with before/after plots.

How do you prove the fix?

Pre/post orbits, Bode/Nyquist, run-up/coast-down and ODS/modal, plus a criteria check and a clear report with plots and as-built details.

Talk to a Rotating Machinery Specialist

Send your spectra and symptoms for a quick triage, or book an on-site survey.

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