What is a pneumatic device emission in oil and gas?

Pneumatic devices at oil and gas facilities use pressurized natural gas to operate control valves and pumps. When they actuate, they vent natural gas (primarily methane) to the atmosphere. EPA classifies these as high-bleed (>6 scf/hr, avg 37.3 scf/hr), low-bleed (<6 scf/hr, avg 1.39 scf/hr), and intermittent-vent (avg 13.5 scf/hr) controllers.

What are the NSPS OOOOa requirements for pneumatic controllers?

Under EPA NSPS OOOOa (finalized 2024), all new, modified, or reconstructed pneumatic controllers at oil and gas facilities must be zero-emission or emit less than 6 scf/hr. Existing high-bleed controllers must be replaced according to the compliance schedule. This effectively requires conversion to instrument air, electric, or low-bleed devices.

How do you calculate methane emissions from pneumatic devices?

Methane emissions are calculated as: Device Count x Emission Factor (scf/hr) x Operating Hours/Year x Methane Fraction x Gas Density (0.0424 lb/scf). EPA provides default emission factors: 37.3 scf/hr for high-bleed, 1.39 scf/hr for low-bleed, and 13.5 scf/hr for intermittent-vent controllers. Results are converted to tons/year and metric tonnes for reporting.

What is the EPA Subpart W reporting threshold for pneumatic device emissions?

Facilities emitting 25,000 metric tonnes of CO2-equivalent per year or more must report under 40 CFR Part 98 Subpart W. Pneumatic device emissions are converted to CO2e using the Global Warming Potential (GWP) for methane: 25 (AR4), 28 (AR5), or 80 (20-year horizon). A single high-bleed controller emits approximately 8.2 MT CO2e/yr using GWP=25.

Pneumatic Device Emissions Calculator | EPA OOOOa Methane & VOC

Pneumatic Controllers

High-Bleed Continuous Controllers

count

EPA default: 37.3 scf/hr per device (>6 scf/hr bleed rate)

Low-Bleed Continuous Controllers

count

EPA default: 1.39 scf/hr per device (<6 scf/hr bleed rate)

Intermittent-Vent Controllers

count

EPA default: 13.5 scf/hr average (includes actuation events)

Pneumatic Pumps

Chemical Injection Pumps

count

EPA default: 70.4 scf/hr per pump

Glycol Circulation Pumps

count

EPA default: 168.4 scf/hr per pump

Gas Properties

Supply Gas Pressure

psig

Gas Methane Content

Gas VOC Content

Operating & Economic Parameters

Operating Hours per Year

hr/yr

Gas Value

$/Mscf

Regulatory & Reporting

Methane Global Warming Potential

NSPS OOOOa Compliance Required?

OOOOa: After 2023, all new/modified controllers must be zero-emission or <6 scf/hr. Existing high-bleed controllers must be replaced per compliance schedule.

Understanding Pneumatic Device Emissions

EPA Device Types:
High-bleed: >6 scf/hr (avg 37.3 scf/hr)
Low-bleed: <6 scf/hr (avg 1.39 scf/hr)
Intermittent-vent: avg 13.5 scf/hr

OOOOa Impact:
Replacing one high-bleed with low-bleed saves ~315 Mscf/yr of natural gas per device, worth ~$945/yr at $3/Mscf.

Why It Matters:
Pneumatic devices account for 5–15% of facility methane emissions. EPA estimates ~477,000 high-bleed controllers remain in service across the U.S. oil and gas sector.

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Understand pneumatic device types, EPA emission factors, OOOOa requirements, and reduction technologies

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Key Emission Factors

E = N × EF × H × x_CH4

E = Annual emissions (scf/yr)

N = Number of devices

EF = Emission factor (scf/hr)

H = Operating hours (hr/yr)

x_CH4 = Methane mole fraction

Standards & References

EPA NSPS OOOOa
Standards of Performance for Crude Oil and Natural Gas Facilities
40 CFR Part 98 Subpart W
Petroleum and Natural Gas Systems GHG Reporting
EPA Natural Gas STAR
Partner Program Emission Factors
API Compendium (2009)
GHG Emissions Methodologies for Oil & Gas

Engineering Notes

High-bleed: 37.3 scf/hr is EPA population average. Actual devices may range from 6 to 70+ scf/hr
Low-bleed: 1.39 scf/hr. Must have continuous bleed rate <6 scf/hr to qualify
Intermittent: 13.5 scf/hr is time-averaged. Zero bleed between actuations
OOOOa 2024: New/modified controllers must be zero-emission or <6 scf/hr
Gas density: 0.0424 lb/scf for methane at standard conditions (60°F, 14.696 psia)
Subpart W: Report if facility total ≥ 25,000 MT CO2e/yr

Quick Reference — Device Emissions

1 high-bleed controller: ~327 Mscf/yr, ~6.9 tons CH4/yr
1 low-bleed controller: ~12.2 Mscf/yr, ~0.26 tons CH4/yr
1 intermittent controller: ~118 Mscf/yr, ~2.5 tons CH4/yr
1 chem injection pump: ~617 Mscf/yr, ~13.1 tons CH4/yr
1 glycol pump: ~1,476 Mscf/yr, ~31.2 tons CH4/yr

Pneumatic Device Emissions Calculator

Pneumatic Controllers

Pneumatic Pumps

Gas Properties

Operating & Economic Parameters

Regulatory & Reporting

Understanding Pneumatic Device Emissions

📚 Learn the Theory

Results

Key Emission Factors

Standards & References

Engineering Notes

Quick Reference — Device Emissions

Related Calculators

GHG Emissions Estimator

Flare Radiation

Glycol Dehydration

Relief Valve Sizing