Frequently Asked Questions: Process Controllers
View frequently asked questions about EPA's 2024 final rule for oil and natural gas operations - process controllers. On this page:
What is considered a process controller under the final rule?
§ 60.5430b “Process controller” and §60.5430c “Process controller” define process controller as “an automated instrument used for maintaining a process condition such as liquid level, pressure, delta-pressure and temperature.”
NSPS OOOOb (§60.5430b) and EG OOOOc (§60.5430c) define a self-contained process controller as “a natural gas-driven process controller that releases gas into the downstream piping and not to the atmosphere, resulting in zero methane and VOC emissions.”
In the oil and gas industry, many process controllers are powered by pressurized natural gas and emit natural gas (including VOC and methane) to the atmosphere. However, process controllers may also be powered by electricity or compressed air, and these types of controllers do not use or emit natural gas. Natural gas-driven process controllers are a significant source of methane emissions.
Natural gas-driven process controllers that function as emergency shutdown devices and process controllers that are not driven by natural gas are not included in the affected facility for NSPS OOOOb or designated facility for EG OOOOc.
Note: EPA changed the terminology from “pneumatic controllers” to “process controllers” in the final rule. See 89 FR 16930.
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