Globally, natural gas demand reached a record 4,122 billion cubic meters (bcm) in 2024 and is expected to increase by 1.7% to 4,193 bcm in 2025.

Transporting this natural gas safely, efficiently, and reliably requires effective overpressure protection (OPP).

In this 2:21 YouTube video, “Three types of Overpressure Protection,” Emerson’s Doug Schleffer highlights three solutions to address overpressure conditions. These solutions include worker monitors, slam shuts, and pressure relief valves.

Depending on the regulatory codes in various jurisdictions, one or two forms of OPP may be required. The Fisher Type EZH and EZL regulators are set in a worker monitor application. If the working unit fails, the monitor regulator will take over to maintain pressure downstream. This arrangement works only for overpressure, not for underpressure conditions.

Doug shows the slam shut OPP form using an integral Fisher OSX unit, which can be added to an existing pressure regulator, such as a Fisher EZR regulator. Slam shut devices shut down the pipeline quickly, and address both overpressure and underpressure conditions. A downstream pipeline break causes an underpressure event, which the slam-shut action on the pressure regulator can soon mitigate. The slam-shut units can be set up as stand-alone or integral units, such as the Fisher OSE slam-shut valve.

The third form of OPP is a pressure relief valve, such as the Anderson Greenwood Series 400 pilot-operated relief valve. These pressure relief valves maintain a steady gas supply while allowing regular operation during a momentary OPP event. They vent gas to the atmosphere and need to be sized based on the pipeline’s maximum possible flow rate.

These three forms of overpressure protection can be used in combination to protect assets and comply with regulatory requirements, thereby maintaining safe, reliable, and efficient operations.

Visit the Natural Gas Overpressure Protection page on Emerson.com for more information on these solutions.