A "Green" Company Since 1990

EconoSep™ "Enhanced Gravity" Oil/Water Separators

Follow this link "Oil Water Separator Design Parameters" for more information on the accurate design and sizing of Oil Water Separators and Separation Systems


The HydroFlo Tech EconoSep™ (ES) Series stainless steel oil/water separator is our economy version coalescing type separator designed for use in a wide range of applications. Our ES series separators are configured to meet the low cost or light duty installation requirements that do not require the sludge hopper, integral oil reservoir, or vapor tight lid assemblies as the TotlSep™ series does. The EconoSep series is available in 7 sizes to handle flows up to 125 gpm.

Our EconoSep separators are designed specifically around the data presented in API pub 421 "Design and Operation of Oil/Water Separators". By following all the API design parameters, the HydroFlo enhanced gravity oil/water separators are the most efficient oil water separators available.

We can outfit our separators with various sizes of our proprietary DynaPac™ cross corrugated coalescing media, as well as unlimited varieties of parallel plate media. This allows us to tailor the design of our oil water separator to meet your specific application.

The internal DynaPac™ cross corrugated coalescing media (available in PVC, polypropylene, and stainless steel) can be flushed with water and reused for years of efficient, trouble free use.

One of the advantages of our design is that the recovered product will typically have a residual water content of less than 3%.


Standard Features:

  • Adjustable effluent weir troughs
  • T304 stainless steel construction
  • PVC DynaPac™ coalescing media (removable for easy cleaning)
  • Effluent pumpout chamber
  • Removable lid assembly
  • Threaded fittings
  • Low profile to take up less space
  • Seamlessly integrates with other HydroFlo offered wastewater products
  • Stand alone operation
  • Capable of handling flows from 5 gpm to 125 gpm and above, in a single above grade tank

Available Options:

  • Chemical pretreatment systems
  • Concrete tank designs for large in ground installations
  • Duplex systems for redundancy
  • Effluent monitoring
  • Effluent sampling
  • Explosion-proof design
  • Flash mix/flocculation tanks with mixers
  • Polypropylene or 316 stainless steel construction
  • Influent equalization
  • Influent / effluent lift stations
  • Instrumentation and controls
  • Removable covers with gaskets
  • On board reagent storage (day tanks)
  • SCADA system monitoring
  • Sludge handling and dewatering


Equipment Design Data & Sizing Calculations
Installation, Operation & Maintenance Manuals

There are many considerations to be taken into account when designing an enhanced gravity oil/water separator. The following needs to be taken into account as a minimum:

1.  Inlet flow distribution

2.  Length to height to width ratios (for proper overall flow distribution)

3.  Cross sectional velocities (actual, not nominal)

4.  Laminar flow conditions

5.  DynaPac™ Cross Corrugated coalescing media or parallel plate media "Reynolds" calculations (for quiescent flow distribution)

6.  Effluent flow distribution

7.  Total projected surface area

These basic design considerations all contribute to the complete utilization of the separation media. Follow them properly and the results will be consistent, equal flow distribution through the separation chamber and the media pack. These are the earmarks of a thoughtful, wholly engineered, fully developed oil/water separator design.

HydroFlo strives to be the benchmark by which all others are judged. By paying total attention to every detail of the separators design, we can supply you with the finest oil/water separator available anywhere.

Equipment Criteria:

The separator shall be a specially fabricated rectangular channel tank. The separation process shall be fully automatic requiring no moving parts. The design of the separator shall satisfy the requirements of API PUBLICATION 421, Feb. 1990 on DESIGN & OPERATION OF OIL/WATER SEPARATORS and Stokes' law. Performance enhancement shall be achieved by the use of DynaPac™ cross corrugated coalescing media.

Separation Cell:

The separation cell is designed using elements of American Petroleum Institute's publication 421 Feb. 1990 “Design of Oil-Water Separators” to ensure the best possible use of particle rise rate performance. The separation cell is a rectangular flat bottom tank manufactured from 304 stainless steel with an effluent surface baffle, 304 stainless steel full width adjustable overflow weir, effluent collection chamber with flanged outlet nozzle and recycle suction port, and angled float beaching plate.

  1. Influent Diffusion Chamber
    The flow shall enter the separator submerged, through an influent diffusion chamber. Dispersion across the depth and width of the DYNAPAC™ is to be achieved through the use of a non-clog diffuser. Heavy solids that fall out of suspension here shall be channeled to the sludge collection chamber.
  2. Separation Chamber
    The Separation Chamber shall be fitted with DYNAPAC™ cross corrugated coalescing media. Adequate space is to be left before and after the chamber to prevent short circuiting through the pack. A total of ____ cubic feet of coalescing media is provided with ½, ¾, or 1-1/4” spacing providing _______ft3 of coalescing surface area.
  3. Sludge Collection Chamber
    The sludge collection chamber shall be located directly beneath the coalescing media pack and provide ample storage capacity for the settled sludge.
  4. Oil Discharge
    The oil discharge port shall be located at the influent end of the separation chamber and incorporate an angled float/oil skimming plate.
  5. Effluent Chamber
    The aqueous phase leaving the DYNAPAC™ shall pass under the oil retention baffle and up over the adjustable 304 stainless steel effluent weir, which shall maintain the liquid level throughout the separator.
  6. Removable Lids
    The entire separator shall be covered with bolt down removable lid
  7. Coalescing Media
    The coalescing media pack shall be fabricated of oleophilic cross corrugated coalescing media manufactured by HydroFlo Tech.


Control Package (Optional):

All HydroFlo Tech oil/water separation systems are fully automated. Control packages (depending on your specific requirements) are available in either basic relay logic controls, or a full state of the art PLC with touch screen HMI and our sophisticated treatment algorithms. The relay logic controls package allows basic reconfiguration of the original system settings, while the PLC based package allows maximum flexibility to change the process parameters, as well as tight control that minimizes chemical usage. We can include a variety of options including digital data logging of critical process parameters, Ethernet access to process data, communication with Building Management Systems, and even remote system access using cellular wireless technology.

All enclosures are NEMA 4X. Where metallic enclosures are used, they are provided with epoxy or polyester finishes for corrosion resistance. All conduit is plastic coated where possible. Low voltage 24VDC is used throughout to minimize service personnel exposure to high voltage. All panels are OSHA LOTO and NFPA 79 compliant. Additionally UL-508 listing is available.

Effluent Monitoring: As mandated by the local controlling authority, the effluent quality must be continuously monitored. A two pen recorder is to be used to monitor effluent flow rate and pH. The recorder is to be equipped with a flow totalizer. Any effluent pH deviations will trigger an alarm and system discharge will be halted.

System Packaging:

The system is supplied as a completely fabricated "turnkey" package. All devices are pre-wired and plumbed.

You need to make the plumbing connections to and from the system and a single electrical connection point for incoming power. The disconnect on the MCP provides OSHA Lock Out / Tag Out and NFPA 79 compliance. For systems requiring compressed air, only one connection is required and a valve is supplied for OSHA LOTO.