Surge & Water Hammer Analysis In Pipelines
Surge and water hammer are critical challenges in fluid systems, often caused by sudden events like valve operations, pump trips, or equipment failures. These events can disrupt steady-state fluid flow, leading to excessive surge pressures, increased pipe stress, and potential system damage.
At Dynaflow Research Group (DRG), we leverage our multidisciplinary expertise in both the dynamic aspects of fluid flow and the mechanical responses of piping systems to address these issues. Our comprehensive surge analysis services aim to assess and mitigate risks, ensuring the safe and efficient operation of your piping systems.
Challenges We Help You Solve
- Large pressures: Can cause permanent deformation or rupture of pipelines
- Low pressures: Risk of pipeline collapse or leakage at joints and seals
- Reverse flow: Potential damage to pump seals and motors, and draining of storage tanks
- Pipeline movement: Overstress and failure of pipe supports and pipelines
- Low flow velocity: Can lead to the settlement of solids in slurry lines, causing blockages
- Large unbalanced loads: Vibration of mechanical structures, excessive loads on flanges and tank nozzles
- Cavitation: Occurrence can lead to problematic vibrations, unbalanced loads, and noise
Discover how we can support your Surge & Water Hammer Analysis related projects
Surge & Water Hammer Analysis for new and existing piping systems
New Piping Systems
- Design Optimization: Identifying potential issues early for cost-effective design decisions
- Scenario Planning: Simulating multiple design scenarios for the safest configuration
- Equipment Sizing: Proper sizing of valves, pumps, and pressure suppression devices
- Regulatory Compliance: Ensuring designs meet safety standards from the outset
Existing Piping Systems
- Problem Diagnosis: Identifying root causes of issues like vibrations and leaks
- Retrofit Planning: Effective modifications or additions to mitigate surge problems
- Operational Optimization: Fine-tuning valve closures, pump operations, and control systems
- Risk Assessment: Evaluating system vulnerability and prioritizing upgrades
New & Existing Piping Systems
- Transient Scenario Modeling: Simulating critical events: valve closures and pump trips
- Pressure and Force Calculations: Determining maximum and minimum pressures and unbalanced forces
- Mitigation Strategies: Providing recommendations for surge prevention
- Fluid-Structure Interaction: Integrating with structural analysis tools to assess fluid-induced forces
- Compliance Verification: Ensuring systems meet industry standards and safety regulations
What kind of systems we conduct surge & water hammer analysis for:
- Piping systems
- Loading lines
- Pump and valve systems
- Fire protection systems
- Heat exchangers
- Storage tanks and reservoirs
- General industrial piping systems
Surge & Water Hammer Case Studies
Piping failures like a deformed bellow, plastically deformed pipe, or restraint failures are often related to a one-time event like a water hammer or surge. In those cases, a large magnitude axial force has likely occurred in the piping.
When a surge wave is responsible for the damage, this can likely be seen at supports. Observations around pipe supporting may indicate that the line has moved in both directions before ending up at its current location. This would indicate that forces in both directions have occurred.
The applicable scenarios in the system are then determined in close consultation with the client. Then, using our in-house software solution BOSfluids, we model the piping system in detail and determine the pressure surges that occur for the applicable scenarios. The pressure time-history and unbalanced forces are obtained. From the assessment of this data, our surge analysis can support the field observations.
Next, DRG determines the possible mitigation measures available for the surge loads on the piping. Typical mitigation measures include surge vessels, vacuum breakers, air valves, changing valve closure or opening times or even re-routing the piping layout. The effectiveness of the mitigation measures is directly assessed using BOSfluids.
Resultant shaking forces are then assessed in the piping analysis software, Caesar II, to verify that they can be accommodated by the piping and support arrangement.
Loading lines are especially susceptible to water hammer due to the PERC or Powered Emergency Release Coupling and high flow rate. The PERC is located at the loading arm and allows the loading arm to quickly detach from the ship in case of excessive ship movement. To limit the amount of fluid lost, the PERC closes in the order of seconds.
The fast closure causes a sudden stoppage of fluid transport with a subsequent pressure surge. The fluid flow is now halted which requires the pumps to be tripped. Pressure increases at the loading arms may cause flow reversal and cavitation at the loading arms. The pressure wave, now at the location of the pumps, causes another flow reversal that may cause implosion of the cavitation bubbles at the loading arms. The implosion of cavitation bubbles typically generates larger pressure surges than valve closure.
With the surge analysis tool of choice, BOSfluids, the described scenarios can be captured in detail. We develop a 3D model of the loading system with the applicable pumps, valves, and other equipment. The exact scenarios are determined in close consultation with the client.
Possible outcomes of the analysis include large pressure surges with accompanying shaking forces. The primary pressure peak may cause pipe rupture whereas the traveling pressure wave causes shaking forces between elbow pairs. Excessive shaking forces may cause restraint failure, nozzle failure, or pipe failure.
Typical mitigation measures include surge vessels, vacuum breakers, air valves, changing valve closure or opening times or even re-routing the piping layout.
Resultant shaking forces are then assessed in the piping analysis software, Caesar II, to verify that they can be accommodated by the piping and support arrangement.
Discover how we can support your Surge & Water Hammer Analysis related projects
Software Solutions For Surge & Water Hammer
Caesar II
DRG conducts piping flexibility assessments using the software Caesar II from Hexagon. Caesar II is used for both static and dynamic piping analyses. We have a thorough understanding of the software and are also an official Caesar II training provider for Hexagon. Caesar II is considered the industry standard for pipe stress analysis.
BOSfluids
Our inhouse developed professional software solution BOSfluids is an interactive and visual software package for the simulation and analysis of fluid flow to determine the flow rates, pressures and unbalanced forces in piping systems. It is an effective tool to study the steady state and transient flow conditions and help you perform coupled fluid-structure analyses.
