Flow Induced Vibration
Services
Asset Integrity performs flow induced vibration (FIV) analysis to mitigate the risk of excessive piping vibration and failures. Our experience with flow induced vibration both in the office and in the field means that our exposure to FIV is well rounded and our proposed solutions are practical and cost effective.
Design studies which are carried out are to internationally recognised criteria such as the Energy Institute Guidelines. Where detailed analysis is required to solve a FIV problem, such as dynamic stress estimates for intrusive devices, our capabilities in finite element analysis and in the field allows us to solve problems quickly and effectively.
Asset Integrity also carries out other services which compliment FIV analysis. These services include finite element analysis (FEA), on-site measurements and troubleshooting, pipe stress analysis, and structural analysis.
About Flow Induced Vibration
In the majority of cases, flow induced vibration (FIV) is caused by flow turbulence in a system. In practice, turbulence will exist within any piping system however the severity is largely dependent on the flow regime and pipe geometry. For most cases, the primary source of turbulence is due to obstructions or direction changes in the system, such as elbows, tees, valves or expanders.
The turbulence can generate high levels of energy which propagate through the system, and although it is typically broad band in nature, the majority of the excitation is often concentrated at low frequencies. This leads to excitation of piping modes, which can cause vibration and fatigue problems in piping, piping restraints, valves and fittings.
Other potential sources for FIV include:
• Flow past an intrusive device such as a thermowell or sample probe (i.e. vortex shedding).
• Flow through an intrusive component such as a strainer or heat exchanger tubes.
• Acoustic excitation of pipe spans and pressure vessels, such as flow over a component or past a ‘dead leg’ branch.
• Cavitation and flashing
Flow induced vibration is best tackled during the design stage of a project. For this reason FIV studies are commonly used to validate and refine the design of new assets or when intending to operate with new flows beyond current design capabilities.
REQUEST QUOTE
“We”ll work to reduce the risk of excessive piping vibration and failures caused by flow turbulence in a system.”
| Typical Problem | - Analysis Type | - Asset |
|---|---|---|
| Design of a petrochemical plant with compliance to Energy Institute (EI) guidelines | - FIV Calculations - Piping Design - FEA | - Pipe |
| Fatigue failure of piping and small bore fittings (SBF’s) | - FIV Calculations - FEA - Field Measurements | - Pipe / Fitting |
| Increased flow required for an existing design whilst maintaining a safe and controlled environment (i.e. flow testing) | - FIV Calculations - Piping Design - FEA - Field Measurements | - Pipe |
| Expansion of existing plant | - FIV Calculations - Piping Design - FEA - Field Measurements | - Pipe |
| Failure of centrifugal compressor suction strainer causing significant downtime | - FIV Calculations - FEA | - Centrifugal Compressor |
| Repeated failure of heat exchange tubes | - FIV Calculations - FEA - Field Measurements | - Heat Exchanger |
| Potential for component failure in process separator | - FIV Calculations - FEA | - Separator |
| Excessive noise and vibration (i.e. possible fatigue failure) of a thermowell | - FIV Calculations - FEA - Field Measurements | - Thermowell |