Liquid Pipeline Surge Events, and How to Safely Control Them

Liquid Pipeline Surge is caused when rapid changes in flow rate occur. These pressure surges can be generated by anything that causes the liquid velocity in the line to change quickly. Such as the opening or closing of an automatic or manual valve, the starting or stopping of a pump or the emergency shutdown of an ESD device. It is because of these possible surge events that it is imperative to have a reliable surge relief system in place to prevent leaks, damages and even injury.
 
In this post we will discuss challenges and best practices when implementing a surge relief system as well as our very own Spartan solution and how we’ve overcome these concerns with an effective, user friendly design.

There are many different versions and designs of surge relief systems available on the market. We have seen and delivered multiple different versions ourselves over the years and have tailored many of them to our customers needs. Of course, some designs are more complex then others, provide more feedback, control and efficiencies. Overall, it really depends on what the customer would like to get out of the system that steers their overall decision.
 
What we found through compiled feedback from our customers are some key elements, requirements and nice to haves, and used this info as our design requirements within our own system. Some key features and benefits of our surge relief system are as follows:
 

• Very high accuracy of nitrogen pressure control
  • Reliable surge overpressure protection, even at pipeline pressures close to maximum allowable operating pressures
  • No setpoint drift normally associated with regulator-based designs
  • Advanced dual PID pressure control
  • Fully digital setpoints, alarm limits, deadbands
• Extremely low nitrogen consumption
  • Up to 1 year per nitrogen supply cylinder
  • The number of days of nitrogen remaining is continuously monitored
  • Alerts and alarms on abnormal nitrogen supply and plenum pressures or excessive consumption
• Robust, fault tolerant design
  • Redundant high-cycle solenoid valves
  • Solenoid valve cycling duty optimization
  • Abnormal event alarms
  • Automatic preservation of plenum pressure on loss of power, loss of nitrogen supply, system fault detection
• Full colour touchscreen operator interface
  • Intuitive graphic-based operation
  • Fully configuration capability from screen – no laptop required
  • Real-time and historical trends
  • Low ambient temperature and bright sunlight display
• Advanced remote connectivity
  • Local PLC connectivity (Modbus over ethernet)
  • Cellular connectivity, including smart cell phones
  • Monitor operation, events, trends, nitrogen consumption
  • Receive alarms and alerts
  • Remotely troubleshoot issues
  • Download historical data, alarm summary