The ESI API-421 Separator is a gravity-type oil-water separator designed for use in petroleum refineries. Design criteria is based on the American Petroleum Institute's (API) Publication 421, "Design and Operation of Oil-Water Separators". Our API-421 Separator includes Diffusers, Reaction-Jets, Sludge Hopper, Flight & Rake System, Corrugated Plate Packs, Oil-Skimming Devices, etc. These internal components reduce flow turbulence, distribute the flow evenly, and help coalesce and remove the oil.

The following parameters are required for proper sizing and design:

Qm = Design flow (maximum wastewater flow).

T = Lowest wastewater temperature.

Sw = Specific gravity of the wastewater.

μ = Absolute/dynamic viscosity of the wastewater.

So = Specific gravity of the oil-fraction.

D = Diameter of the oil globule to be removed.

Additional design constraints are as follows:

Vh = Horizontal Velocity should be ≤3ft/minute or 15x the oil globule rate of rise (Vt), whichever is smaller.

d = Separation Depth should be 3-8 feet.

Depth (separator) to width (separator) ratio should range from 0.3 to 0.5.

Separator width is usually 6-20 feet.

Two Channels are usually provided for servicing or cleaning one channel while the other is in service.

Length to width ratio (L/B) should be ≥5.

API-421 Separator Package Includes

Engineered for Specific Application

Inlet Distribution System

Solids Collection and Removal

Oil Collection and Removal

Secondary Oil Removal with Optional Plate Pack