- Highly effective oil removal: Designed and built to API 421 specifications with coalescing media to meet low discharge limits.
- Compact & scalable designs: Models from 15 to 500 GPM; ideal where gravity-only tanks won’t fit.
- Built for tough oil feeds: Handles fuels, lube oils, hydraulics, LNAPL/DNAPL & other hydrocarbons.
- Minimal moving parts = low maintenance: Engineered for long service with easy sizing calibration.
- Customizable & durable: Skids, coatings, stainless or carbon steel, adjustable weirs, forkliftable bases.
IN STOCK. READY TO SHIP.
No 12–16 week lead times. Systems are ready to deploy fast so you can reduce downtime and manage oily water efficiently.
API Coalescing Oil Water Separator (OWS) Features
Industrial-Grade Coalescing Oil-Water Separation – High-Efficiency Oil Removal
SkimOIL® API Coalescing Oil Water Separators provide reliable, high-efficiency oil removal for industrial pits, tanks, wash racks, and process water systems. Designed and built to API 421 specifications with coalescing media, these separators remove free and dispersed oils, LNAPLs/DNAPLs, and a wide range of hydrocarbons while minimizing footprint and maintenance.
01
Design
- Compact, scalable construction: Models from 15 to 500 GPM fit tight spaces where gravity-only tanks won’t work.
- Rugged materials: Carbon or stainless steel with epoxy coating, sectional covers, and forkliftable skid bases.
- Integral oil reservoir and adjustable weirs: Optimizes separation and temporary oil storage.
- Modular options: Expandable effluent chambers, custom coatings, and site-specific configurations.
- Passive coalescing technology: Coalescing plates create laminar flow to accelerate droplet rise and improve oil separation.
02
PERFORMANCE
- High-efficiency oil removal: ≤100 mg/L for droplets ≥150 µm; actual performance can reach ~50 mg/L under ideal conditions.
- Solids handling: Manages 40–100 mg/L total suspended solids; influent oils ≤1250 mg/L.
- Minimal moving parts: Reduces maintenance and ensures long service life.
- Broad industrial applicability: Ideal for refineries, groundwater remediation, vehicle/military wash racks, steel mill condensate, stormwater, shipping, tank farms, and process water.
- Proven coalescing efficiency: Exceeds traditional gravity separators with smaller footprint and faster throughput.
03
INSTALLATION & MAINTENANCE
- Easy deployment: Forkliftable skids with lifting lugs and flat-bottom design simplify installation.
- Low maintenance: Minimal moving parts, simple cleaning, and robust construction.
- Long-term durability: Heavy-duty steel, epoxy coatings, and sectional covers ensure corrosion resistance.
- Flexible site integration: Adjustable water weirs, expandable effluent chambers, and custom skids accommodate various industrial setups.
WHY API COALESCING OIL WATER SEPARATORS MATTER
When reliable, high-efficiency oil removal is essential, SkimOIL® API Coalescing OWS deliver industrial-grade separation with minimal maintenance. Built to handle hydrocarbons, fuels, lubricants, and LNAPLs/DNAPLs effectively, these separators offer compact, durable solutions for refineries, wash racks, tank farms, stormwater systems, and other industrial oily water applications—ensuring clean discharge, lower disposal costs, and smooth, uninterrupted operations.
What This API OWS Can Remove
Motor oils, fuels (vehicle/jet), fuel oils, hydraulic fluids, immiscible machining oils, lube oil, transmission fluid, bunker C, LNAPLs, DNAPLs, vegetable oils, crude, compressor lube oil & other hydrocarbons (BTEX, etc.). Model sizing is based on oil specific gravity, droplet size removal requirements, and waste stream parameters.
Available Models & Flow Rates
| API-15 | 15 |
|---|---|
| API-25 | 25 |
| API-50 | 50 |
| API-100 | 100 |
| API-150 | 150 |
| API-200 | 200 |
| API-250 | 250 |
| API-300 | 300 |
| API-400 | 400 |
| API-500 | 500 |
| Flow rates are nominal. Sizing of system is based on application parameters. Contact Skimoil for sizing of your application. |
Key Features
- Integral oil reservoir
- Forkliftable skid with lifting lugs
- Flat bottom design
- Sectional cover with zinc hardware
- Carbon or stainless steel construction
- Adjustable water weir
- Expandable effluent chamber
- Epoxy coating interior/exterior
- Target performance: ≥150 mg/L oil residual
Performance Specifications
- Oil/fuel removal: ≤100 mg/L for oil droplets ≥150 µm.
- Solids (TSS): 40–100 mg/L
Based on influent loadings: ≤1250 mg/L oils, ≤500 mg/L solids.
Where ideal conditions apply, discharge can reach ~50 mg/L , but actual performance varies based on waste upstream conditions.
OWS Theory & Design Logic
Separation Mechanism
Coalescing Oil Water Separators use passive gravity and plate coalescing technology. The system design applies both Stokes Law and modern plate theory to accelerate droplet rise.
Water flows horizontally into diffusors, then through coalescing media creating laminar flow. Oil impinges, coalesces, and detaches; solids settle in the v‑hopper beneath.
Stokes Law Clarified
Stokes Law relates droplet rise velocity to size and density. Larger droplets rise faster—design exploits these principles so oil encounters coalescing media quickly, improving separation efficiency.
Coalescing Media
Media design creates quiescent flow, reducing turbulence. Solids settle out, and droplets coalesce. Proper hydraulic distribution ensures flow uses full media cross-section—Reynolds number kept <500 to prevent short-circuit flow.
Coalescing plates smooth and angled—optimizing oil growth and separation performance.
Gravity vs. Coalescing
Traditional gravity API separators require larger tanks and achieve ~100 ppm. Coalescing plates provide much higher performance (>10 ppm oil), with smaller footprint and faster throughput.
SkimOIL ® ’s coalescing OWS deliver ≤10 ppm performance for 20–30 µm droplets in many applications
Typical Applications
Groundwater remediation, refinery process water separation, vehicle wash racks, military equipment wash, industrial process water (hydraulic/machining), steel mill condensate capture, stormwater runoff treatment, shipping deck/bilge water, tank farm dewatering, petrochemical and power generation oily waste, and heat treating rinse water cleanup.
Need help choosing the right size or options?
- Call SkimOIL ® today – we specialize in total oil removal systems.