What Is API 421 and Why Does It Matter?
API 421, formally titled “Management of Water Discharges: Design and Operation of Oil-Water Separators,” is the industry’s primary reference for sizing and designing gravity-based oil-water separators. It establishes the baseline criteria for achieving predictable oil droplet removal under controlled flow conditions. Key specifications include: Here’s the catch:Most API concrete tanks fail to meet these requirements […]
What Types of Oil Do Oil-Water Separators Remove?
Not all oils behave the same in water, and understanding the differences is crucial for choosing the right separation technology. Oils in wastewater are generally categorized into four types: Mercer systems specialize in removing free and dispersed oil, capturing droplets down to ~60 microns under real-world loading, in line with API 421 targets. By removing […]
What Is an Oil-Water Separator and How Does It Work?
An oil-water separator is a wastewater treatment device designed to remove oils, greases, hydrocarbons, and settleable solids from contaminated water. While all separators rely on gravity, not all gravity systems work the same—and performance varies dramatically depending on design. Traditional systems like API and CPI separators rely on simple tank geometry or corrugated plates. These […]