Surge Analysis

When your process or production system is at continuous operation, the pressures and flow rates are constant. For normal operating conditions, the piping system is able to withstand the resulting stresses.


However, when a sudden event occurs, like valve operations, a tripping pump or failure of equipment, the steady-state fluid flow is disturbed. One consequence may be excessive surge pressures and consequently an increase in pipe stress and loads.


Without careful timing of valves, the occurring surge pressures can easily reach tens of bars. For fiberglass systems such overpressure may cause the pipe to fail, especially joints and flanges are sensitive for overpressure. During a transient event low (negative) pressures may also occur. Large diameter fiberglass systems are especially sensitive to low or sub-atmospheric pressures as they are prone to buckling.


Possible mitigation measures for non-vacuum resistant piping are changes to how the system is operated or the introduction of adequately sized buckling rings.


DRG can act as a very capable partner to analyze your system from a dynamical perspective considering water hammer and pressure surges. When problems are found we closely discuss how to resolve the issues by carefully selecting any counter measures like the incorporation of surge vessels, vacuum breakers, air valve or a rerouting of a part of the piping system.

ConditionsPotential Problem
Large pressuresPermanent deformation or rupture of the pipeline
Low pressuresCollapse (buckling) of the pipeline or leakage at joints and seals
Reverse flow
  • Damage to pump seals and brush gear on motors
  • Draining of storage tanks and reservoirs
Pipeline movement
  • Overstressing and failure of pipe supports
  • Failure of the pipe
Low flow velocityMainly a problem in slurry lines, causing settlement of entrained solids and line blockage
Large unbalanced loads
  • Vibration of the mechanical structures
  • Excessive loads on flanges and (low) tank nozzles

DRG developed BOSfluids to solve for water hammer and surge problems. BOSfluids is an interactive computer simulation package that models steady state and transient flow in liquid or gas carrying piping systems. DRG has more than 30 years of experience with these problems. This experience is incorporated in BOSfluids and we are continuously transferring our knowledge and that of our users into new versions of the software.

Our portfolio includes and is not limited to the following projects:


  • Future Pipe Industries – Multiple surge projects contracted by British Petroleum, Jacobs, Fluor, etc.
  • Shell Qatar – Surge calculations of a tank farm to Jetty pipeline on Pearl GTL
  • Shell – Surge calculations for different systems including: Port Dickson, Shell Pernis, Bukom, IOINIO LNG plant, Harweel Cluster, SASREF, Utorogu, etc.
  • NOV Fiberglass Systems – Surge and dynamic analysis of a Firewater system – OFON Phase 2 Total E&P Nigeria
  • British Petroleum
  • BASF – Surge and dynamic stress calculations of different Jetty systems
  • GLT Plus – Transient flow analysis of the Deluge Firewater System Norg underground storage
  • IV Oil & Gas – Surge and dynamic calculations of Winksele Compressor Station, Helwin platform, Dolwin platform,
  • Jord Oil & Gas – Surge and dynamic simulation of Nuvoil compressor skids
  • Cryonorm systems – Surge analysis of LNG facilities