The US Environmental Protection Agency (EPA) 40 CFR Part 60 Subpart OOOO, or Quad O, is a federal regulation under the Clean Air Act for reducing harmful air quality emissions from oil and gas facilities.

The EPA issued a final rule effective May 7, 2024, containing new source performance standards (NSPS) regulating greenhouse gases (GHGs) and volatile organic compound (VOC) emissions for the oil and gas industry. It also finalized guidelines for states to follow in developing their emission reduction standards for limiting fugitive emissions from existing sources.

What is “Quad-O”?

The US Environmental Protection Agency (EPA) 40 CFR Part 60 Subpart OOOO is colloquially known as “Quad-O”. It is a regulation under the Clean Air Act meant to identify emissions sources in oil and natural gas operations contributing to pollution and reduce emissions. The emissions of methane and VOCs from oil and gas equipment used in the production and processing and the transmission and storage of natural gas are affected.

Although there are many different hydrogen production types including black, pink, turquoise, and yellow, the most common type is from “grey” sources (95%). The steam/methane reforming process is used to convert natural gas or methane into hydrogen. A pollutant by-product of this process is CO₂.

Flare gas stacks and combustors are used in many industries including oil & gas, industrial, biogas, and wastewater treatment. These systems are important for burning waste gases produced during operations such as drilling, chemical processing, or biogas reclamation.

In some locations, drilling for oil or natural gas releases hydrocarbon gases that can’t be captured and used, so a gas flare or combustor is needed to relieve excess pressure in the system. Flaring is also used during construction, testing, and maintenance of newly drilled wells or fracking sites.

Digesters used in landfills or wastewater facilities break down waste and produce methane and carbon dioxide, two greenhouse gases (GHGs) that are typically flared, collected for use as a fuel gas in equipment used at the facility, or stored for sale. Flares burn the biogas or waste gases to minimize harmful GHG emissions when flaring becomes necessary due to pressure release events. 

The accuracy of a thermal mass flow meter is dependent upon the technology type and the quality of the materials used for the meter’s sensor design. A well-designed sensor is made to measure flow accurately over a long period of time with minimal drift, independent of recalibration and calibration validation diagnostics. For a thermal mass flow meter, the materials used in the manufacture of the sensor play a vital role in the overall performance of the sensor. The materials must create the best environment for heat transfer - the essential principle of thermal mass flow measurement - or the accuracy and response time suffer.

What is Flow Rate and Why is It Important in Process Applications?

In an industrial setting, controlling processes with accurate data is an essential part of keeping the process running smoothly. Control systems are equipped with instrumentation like thermal flow meters to feed flow data like gas temperature and gas flow rate into the system. So, what is flow rate and why is it important? The flow rate of the gas tells the system how much of a gas is flowing through a cross section of a pipe at a prescribed unit of time. Flow rate data can help with many things, including the following:

Common Results of Gas Uses in Industrial Processes

There are three key results of measuring the flow of air or gases with industrial gas flow meters in industrial applications:

1. efficiency improvement
2. leak reduction
3. increased product quality

Excessive gas consumption wastes money - and of greater importance - can affect product quality and safety. The pharmaceutical industry uses large quantities of nitrogen, oxygen, carbon dioxide gas, and air. Without good air and gas flow measurement, cost, quality, and consumer safety will suffer.

This blog was originally posted by Fox Thermal.

Fox Thermal manufactures a full line of advanced thermal mass flow meters. Each flow meter is manufactured to strict quality standards, calibrated to NIST standards in their state-of-the-art calibration labs, and customized for your application needs.