Controlling Liquid Pipeline Surge Pressure

The RBN Energy blog is a must read for those in the oil & gas upstream, midstream and downstream industries as they analyze the trends and global dynamics impacting companies. Posts such as The Flows They Are A-Changin’ – Westward Natural Gas Flows Into Texas On The Rise describe the flow reversals in natural gas in the U.S. as LNG plants are built along the Gulf coast and vast amounts of shale gas are produced in the Northeast. Similarly, liquids pipelines have seen changes due to new supplies from shale oil producing areas and the opening of U.S. crude oil exports in 2016.

For the pipelines carrying crude oil or natural gas liquids managing pressure surges in the pipeline is an important for safety and the environment. The Current Flow Solutions blog has a post, Control Liquid Pipeline Pressure Surges and Ensure HSE Protection that describes pipeline pressure surge, its causes and considerations in selecting surge relief valve to mitigate the large pressure swings. These swings can be caused by sudden emergency shutdown valve or other manual or automatically controlled valve, or the starting/stopping of a pipeline pump.

Here’s the impact:

Typical Pressure/Time Response with and without Surge Relief Protection

Typical Pressure/Time Response with and without Surge Relief Protection

Rapid changes in flow velocity can produce rapid pressure surges. If these surges are not controlled immediately before they exceed the pressure limits, they can damage your equipment and become a serious safety and environment hazard…

The post lists considerations in sizing a selecting a surge relief valve for the applications including the valve response time, valve flow coefficient (Cv), excess pressure above setpoint to reach required flow rate, and the valve characteristic control curve.

Emerson's Dave Seiler

Read the post for more on the selection considerations and complete surge systems to optimize pipeline integrity.

I wanted to highlight this recorded one-hour webinar by Emerson’s Dave Seiler. In it he discusses the most common causes of pipeline surge pressures and various methods in use to mitigate potentially damaging surge pressures.

Dave also describes a modular approach in a solution to make sure pipeline pressures do not exceed the maximum allowable operating pressures of the pipeline system.

You can connect and interact with other surge valve and pipeline flow experts in the Valves and Flow groups in the Emerson Exchange 365 community.

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