A "Green" Company Since 1990

Pressure Rated 2, 3 & 4 Phase Oil/Water Separators

Pressure Rated

Two Phase Separators

Gas/Liquid, Liquid/Solid and Oil/Water

Three Phase Separators

Gas/Oil/Water or Oil/Water/Solids

Four Phase Separators


Oil Water is used as a reference to any two immiscible liquids of different specific gravity


Follow this link for information on Hydro-Flo's

"Oil Water Separator Design Parameters"

for information on the accurate design and sizing of
Oil Water Separators and Separation Systems

These specialty separators are designed for sophisticated process and wastewater applications. Used in refineries and specialty processes worldwide, these heavy duty separators can be configured to separate a gas from a myriad of immiscible liquids and suspended solids or any immiscible liquids and solids of different specific gravity.

One of the key benefits of this device is its ability to deal with suspended solids. Often, the separation process is hampered by the presence of suspended solids, but this separator does an excellent job of removing suspended solids from the process stream while maintaining its high gas and liquid separation efficiencies.

Call a HydroFlo application engineer today for details.

Standard Features:

  • Epoxy coated ASME coded pressure vessel

  • Factory tested
  • Carbon steel plate packs
  • Seamlessly integrates with other Hydro-Flo offered wastewater products
  • Stand alone operation
  • Standard units can be manufactured for flows from 5 gpm to 3000 gpm and above
  • Structural steel support legs

Available Options:

  • Access platforms with ladder or stairs

  • Automatic sludge pump out packages
  • Chemical pretreatment systems
  • Duplex systems for redundancy
  • Effluent monitoring
  • Effluent sampling
  • Explosion-proof design
  • Flash mix/flocculation tanks with mixers
  • Influent equalization
  • Influent / effluent lift stations
  • Instrumentation and controls
  • Removable covers with gaskets
  • Integral mechanical sludge thickener
  • On board reagent storage (day tanks)
  • Pilot size units for on-site testing
  • Potable water design
  • SCADA system monitoring
  • Special coatings and plate materials
  • Sludge handling and dewatering


Equipment Design Data & Sizing Calculations

Oil Water Separator
  Design Parameters

Application Questionnaire


General Arrangement


• Standard Engineering

"Common" Engineering
  Applicable to all Hydro-Flo
  Manufactured Equipment

Installation, Operation & Maintenance Manuals

Standard IO&M Manual

General IO&M
  Applicable to all Hydro-Flo
  Manufactured Equipment

There are many considerations to be taken into account when designing an enhanced gravity separation system. The following needs to be taken into account as a minimum:

  1. Inlet flow distribution

  2. Cross sectional velocities (actual, not nominal)

  3. Laminar flow conditions

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

  5. Effluent flow distribution

  6. 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 multi phase separator design.

Hydro-Flo 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 multi phase separator available anywhere.

Equipment Criteria:

The separator shall be a specially fabricated vertical cylindrical pressure vessel. 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 vertical cylindrical pressure vessel manufactured from carbon steel.

  1. Influent Diffusion Chamber
    The flow shall enter the separator, through an tangentially mounted influent diffusion nozzle. Gas will enter the chamber and flow upward toward the de-misting filters. Liquids will be carried along the outer surfaces of the inlet chamber and merge with the liquid layer around the perimeter of the separator. Liquids and solids will flow downward into the separation 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 conical in configuration and located at the bottom of the unit directly beneath the coalescing media pack and provide ample storage capacity for the settled sludge. The sides of the chamber shall be sloped at 45 degrees to insure easy and complete removal of the settled sludge.
  4. Oil collection chamber
    The oil collection chamber shall be located at the upper end of the separation chamber and incorporate centrally located oil evacuation connections.
  5. Effluent Chamber
    The aqueous phase leaving the DYNAPAC™ shall pass under a flow distribution baffle and into the centrally located effluent plumbing manifold.
  6. Access Man-way
    The separator shall come equipped with a access man-way large enough for the installation, maintenance and removal of the internal separation medias.
  7. Coalescing Media
    The coalescing media pack shall be fabricated of oleophilic cross corrugated coalescing media manufactured by HYDRO-FLO TECHNOLOGIES.

Control Package (Optional):

All Hydro-Flo Technologies 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.