Separators & Filter Vessels
We design and fabricate ASME-certified separators and filter vessels — including gas-liquid separators, oil-water separators, filter vessels, and custom separation systems — for process pressures from full vacuum to 10 MPa, using carbon steel, 304/316L stainless steel, duplex steel, and lined carbon steel.
What Are Separators and Filter Vessels?
Separators and filter vessels are pressure-rated process equipment that remove one phase or contaminant from a flowing stream — liquid droplets from gas, oil from water, or solid particles from liquid — using gravity, coalescence, centrifugal force, or filtration media.
A separator helps different phases settle, collect, or leave through different outlets. A filter vessel uses replaceable media, such as filter bags or cartridges, to capture particles from liquid or gas streams.
Our separation equipment scope includes four main types: gas-liquid separators, oil-water separators, filter vessels, and custom separation systems. They are used in oil & gas, chemical processing, water treatment, compressed air systems, petrochemical plants, utilities, and general process lines where stable downstream operation depends on cleaner gas, cleaner water, or cleaner liquid.
Separators and Filter Vessels Built for Different Separation Duties
Our separators and filter vessels are grouped by separation duty, so engineers can quickly choose the right equipment based on medium, flow rate, pressure, contaminant type, and outlet quality requirement.
Wet gas, oily water, solid particles, and mixed gas/oil/water streams need different vessel layouts, internals, residence time, and maintenance access.
Gas-Liquid Separators
For wet gas, vapor streams, and liquid carryover control.
Gas-liquid separators remove entrained liquid droplets from gas or vapor streams before compressors, pipelines, burners, heat exchangers, or downstream process equipment.
Typical configurations include vertical designs for limited installation space and horizontal designs for higher gas flow or larger liquid loading. Internals can include inlet devices, baffles, vane packs, wire mesh demisters, mist eliminators, and vortex breakers.
- Droplets ≥3–5 μm captured at ≥99% with wire mesh demister under suitable operating conditions.
- Vertical and horizontal vessel configurations available.
- Design pressure up to 10 MPa for standard project scope.
Commonly used before compressors and downstream gas equipment.
Oil-Water Separators
For oily wastewater, produced water, refinery wastewater, and industrial drainage.
Oil-water separators separate free oil from water using gravity settling, coalescing plates, and controlled flow distribution.
Separation performance depends on inlet oil concentration, oil droplet size, water temperature, specific gravity difference, retention time, and plate pack design.
- CPI design can support outlet oil content around 10–15 ppm under suitable inlet conditions.
- API 421 reference droplet size often uses 150 μm for gravity separator design.
- Capacities up to 500 m³/h depending on oil content and outlet target.
Suitable for free oil separation before further treatment.
Filter Vessels
For solid particle removal from liquid or gas streams.
Filter vessels use bags, cartridges, or other filter elements to remove solid particles from liquid or gas streams.
Bag filter housings are often used for moderate solid loading and simple replacement. Cartridge filter housings are commonly used for finer filtration, larger filter area, or more stable outlet quality.
- Filtration ratings from 1–200 μm depending on filter element selection.
- Flow capacity up to 800 m³/h depending on viscosity, pressure drop, and filter area.
- Single-bag, multi-bag, cartridge, and quick-open closure designs available.
Used where element access and replacement cost matter.
Custom Separation Systems
For mixed phases, special media, or process conditions that standard vessels cannot cover.
Custom separation systems combine vessel design, separation internals, piping, valves, instruments, controls, and skid-mounted packages around your process data.
Typical examples include three-phase separators, gas/oil/water packages, multi-stage filtration packages, separator + filter combinations, and special service equipment for high pressure, corrosive media, sour service, or limited installation space.
- Three-phase oil/gas/water separation available.
- Pilot testing or process verification available when required.
- ASME and PED certification options available for export projects.
Built around process data, outlet target, and installation limits.
Start with the medium, flow rate, pressure, contaminant type, and outlet quality target. Our engineering team can help narrow the direction before detailed quotation.
Quick Comparison of Separator and Filter Vessel Types
Different separation duties require different vessel structures and internals. Use the comparison below to check the main equipment type before reviewing sizing, performance, and project requirements.
| Product Family | Separation Target | Typical Performance | Pressure Range | Typical Industries |
|---|---|---|---|---|
01
Gas-Liquid Separator | Liquid droplets from gas or vapor | ≥99% removal of droplets ≥3–5 μm with wire mesh demister under suitable conditions | Full vacuum to 10 MPa |
Oil & gas
Chemical
Compressed air
Petrochemical |
02
Oil-Water Separator | Free oil from water | Outlet oil content around 10–15 ppm with CPI design under suitable inlet conditions | Atmospheric to pressure-rated design |
Water treatment
Refinery
Produced water
Industrial wastewater |
03
Filter Vessel | Solid particles from liquid or gas | 1–200 μm filtration rating depending on bag or cartridge selection | Full vacuum to 10 MPa |
Chemical
Water treatment
Food process
Utilities |
04
Custom Separation System | Gas, oil, water, solids, or mixed contaminants | Designed according to process data, outlet quality target, and operating duty | Project-specific, up to 10 MPa standard scope |
Oil & gas
Chemical
Energy
Modular process systems |
Gas-Liquid Separator
Liquid droplets from gas or vapor
≥99% removal of droplets ≥3–5 μm with wire mesh demister under suitable conditions
Full vacuum to 10 MPa
Oil & gas, chemical, compressed air, petrochemical
Oil-Water Separator
Free oil from water
Outlet oil content around 10–15 ppm with CPI design under suitable inlet conditions
Atmospheric to pressure-rated design
Water treatment, refinery, produced water, industrial wastewater
Filter Vessel
Solid particles from liquid or gas
1–200 μm filtration rating depending on bag or cartridge selection
Full vacuum to 10 MPa
Chemical, water treatment, food process, utilities
Custom Separation System
Gas, oil, water, solids, or mixed contaminants
Designed according to process data, outlet quality target, and operating duty
Project-specific, up to 10 MPa standard scope
Oil & gas, chemical, energy, modular process systems
How to Choose the Right Separator or Filter Vessel
The right separator or filter vessel depends on the phase or contaminant you need to remove, the required outlet quality, flow rate, operating pressure, temperature, and the maintenance method your plant can accept.
Many RFQs begin with a general phrase such as “separator vessel” or “filter housing,” but the correct solution depends on what is being separated and how clean the outlet stream must be.
What Are You Separating?
Choose by duty firstLiquid Droplets from Gas
≥99% removal of droplets ≥3–5 μm with mesh pad under suitable operating conditions.
Oil from Water
Outlet oil content around 10–15 ppm with CPI design when inlet conditions are suitable.
Solids from Liquid
1–200 μm filtration rating depending on element type and process requirement.
Gas + Oil + Water
Designed by gas flow, liquid loading, interface control, residence time, and outlet targets.
Mist or Aerosol Below 3 μm
Project-specific design after confirming aerosol size, pressure drop, and maintenance limits.
Wrong selection can become operating cost.
Undersizing, over-filtering, or giving the separator too little residence time may look acceptable on a drawing, but it can create carryover, fast element blockage, or unstable outlet quality in operation.
Separation Principles and Typical Performance
Separator performance is controlled by the separation mechanism, droplet or particle size, gas or liquid velocity, residence time, internal design, and allowable pressure drop.
Basic Separation Mechanisms
How separation happensGravity Settling
The vessel slows the stream so heavier droplets or solids can fall, or lighter oil droplets can rise.
Coalescence
Small droplets touch each other and merge into larger droplets that separate more easily.
Centrifugal Separation
Rotating flow pushes heavier droplets toward the vessel wall before they drain or collect.
Filtration Media
Bags or cartridges physically capture particles as the stream passes through the vessel.
Typical Mechanisms and Performance Ranges
Reference values depend on operating conditionsGravity Settling
The vessel slows the flow so heavy droplets can fall or oil droplets can rise before the outlet.
Vane Pack / Baffle
The flow changes direction several times, and droplets hit the plates instead of following the gas path.
Wire Mesh Demister
Fine droplets collide with wire mesh, combine into larger drops, and drain back into the vessel.
Cyclonic Separation
The inlet creates a rotating flow, and heavier droplets move outward by centrifugal force.
Coalescing Plate / CPI
Inclined plates shorten the distance oil droplets must travel before they rise and collect.
Bag / Cartridge Filtration
Particles are trapped by filter media while the cleaned stream passes through the vessel outlet.
Engineering Calculation Note
For gas-liquid separator sizing, vessel diameter is often checked with the Souders-Brown equation. For mesh-pad units, a common K-factor reference range is 0.07–0.11 m/s, but the final value depends on pressure, density, liquid loading, foaming tendency, and the selected demister type.
General Technical Specifications
Our separators and filter vessels can be customized by pressure, temperature, diameter, material, internal structure, inspection level, and export certification requirement.
Design Pressure
Full vacuum to 10 MPa; higher pressure can be reviewed by project.
Design Temperature
-45°C to 400°C depending on material, gasket, internal design, and code requirement.
Vessel Diameter
300–4,000 mm standard manufacturing range.
Materials
SA-516-70 carbon steel, SA-240 304/316L stainless steel, 2205 duplex stainless steel, lined carbon steel.
Design Codes
ASME Section VIII Div. 1 with U-Stamp, PED 2014/68/EU, GB150.
Inspection
RT 100% or spot RT, UT, PT, hydrostatic test at 1.3 × MAWP, helium leak test optional.
Internals
Wire mesh demister, vane pack, baffle, CPI plate pack, filter bag, cartridge element, vortex breaker, distributor.
Closure Options
Bolted cover, davit-assisted cover, quick-open closure where permitted by design code.
Surface Treatment
Sandblasting and painting, pickling and passivation, polishing, internal lining, insulation support.
Typical Lead Time
6–12 weeks depending on vessel size, material, internals, inspection, and documentation scope.
Need a condition outside this range?
Send your pressure, temperature, flow rate, material, outlet requirement, and drawings. We can review whether a custom separation system, special material, or different vessel layout is more suitable.
Applications by Industry
Separators and filter vessels are used in industrial plants where gas, liquid, oil, water, or solids must be controlled before the next process step.
Oil & Gas Industry
01Oil & gas projects often use gas-liquid separators at wellheads, compressor inlets, gas gathering stations, and produced water treatment lines. For sour service or three-phase oil/gas/water duties, material and control requirements can be reviewed according to the project specification.
- Gas-liquid separation before compressors or pipelines.
- Custom systems with level control, interface control, and mist elimination.
Chemical Industry
02Chemical plants use separators to remove mist from reactor off-gas, recover solvent droplets, protect vacuum pumps, and stabilize vapor or liquid streams before downstream equipment. For corrosive media, material selection can be reviewed by temperature, chloride level, pH, and cleaning conditions.
- Protection of vacuum pumps and downstream process equipment.
- 316L, duplex, or lined carbon steel review for corrosive service.
Water Treatment
03Water treatment systems often require oil-water separators, filter vessels, and multi-stage separation before discharge, reuse, or further treatment. CPI plate packs can improve oil droplet rise efficiency, while bag and cartridge housings are used for pre-filtration or polishing duties.
- Oil-water separation before reuse, discharge, or downstream treatment.
- Bag and cartridge vessels for suspended solids control.
Compressed Air & Utility Systems
04Compressed air systems need moisture and oil control after air receivers, dryers, or compressor discharge lines. A gas-liquid separator or filter vessel can remove condensed water, oil mist, or particles before instruments, pneumatic tools, or process users.
- Stable drainage, demister selection, and pressure drop control.
- Protection for instruments, pneumatic tools, and user points.
Food & Beverage Industry
05Food and beverage process lines may require stainless steel filter vessels, cleanable internals, polished surfaces, and gasket materials suitable for the medium. Sanitary-style details should be confirmed by cleaning method, surface finish, viscosity, and product contact requirements.
- Filter vessels for clean process lines and product-contact review.
- Gasket, finish, and cleaning requirements checked case by case.
Manufactured and Tested in Our Pressure Vessel Workshop
Our manufacturing process includes material cutting, plate rolling, welding, nozzle fitting, internal support fabrication, internal component installation, non-destructive examination, hydrostatic testing, internal re-inspection, surface treatment, packaging, and shipment preparation.
Manufacturing Process
Each separator or filter vessel is fabricated through controlled workshop steps, from raw material preparation to final inspection and shipment packaging.
Material Preparation
Cutting, plate rolling and material traceability review before fabrication starts.
Shell Fabrication
Welding, nozzle fitting, supports and main vessel assembly are completed to drawing.
Internal Support Fabrication
Supports, frames, distributors and mounting parts are fabricated for the selected internals.
Internal Component Installation
Demister pads, vane packs, CPI plates, baffles, filter bags or cartridges are installed.
Inspection & Testing
NDE, dimensional checking, hydrostatic testing and internal re-inspection are arranged.
Surface Treatment & Shipment
Painting, passivation, lining, packaging and export shipment preparation are completed.
Internal Parts Are Not Decorative Parts
For separation equipment, the internals directly affect droplet capture, oil-water separation, pressure drop, drainage behavior, and maintenance access.
Inspection and Documentation Options
Inspection options can be matched to project specifications, certification requirements, and export documentation needs.
Certified Project Support
For certified projects, we can manufacture according to ASME Section VIII Div. 1 with U-Stamp and provide PED-related documentation when required.
01 What is the difference between a separator and a filter vessel?
A separator removes phases by gravity, coalescence, centrifugal force, or internal flow control, while a filter vessel removes particles through filter media. A gas-liquid separator separates liquid droplets from gas. An oil-water separator separates oil from water. A filter vessel uses bags or cartridges to capture solids or fine contaminants.
02 What droplet size can a gas-liquid separator remove?
A gas-liquid separator with a wire mesh demister can typically remove droplets ≥3–5 μm at ≥99% efficiency under suitable gas velocity and liquid loading. A vane pack or baffle design is normally used for larger droplets, often ≥10–20 μm, with typical removal efficiency around 96–98% under suitable conditions.
03 How do I size a separator vessel?
A separator vessel is sized by flow rate, pressure, temperature, gas and liquid density, liquid loading, droplet size target, allowable pressure drop, and required residence time. For gas-liquid separators, vessel diameter is commonly checked with the Souders-Brown equation. Send us your process data and we can review the required diameter, length, nozzles, and internals.
04 Can you design to API 421 or NACE MR0175?
Yes, we can review API 421 oil-water separator requirements and NACE MR0175 sour service requirements when they are specified in your project documents. For API 421-style oil-water separation, we check flow rate, oil droplet size, specific gravity difference, temperature, and outlet oil target. For NACE service, material selection and welding requirements must be confirmed before fabrication.
05 What information do you need for a quotation?
For a quotation, we need flow rate, operating pressure, operating temperature, medium composition, and required separation target. If available, please also send inlet contaminant concentration, outlet quality requirement, droplet or particle size, material preference, design code, nozzle orientation, installation space, and any drawing or datasheet from your engineering team.
06 What is the typical lead time and can you ship worldwide?
The typical lead time for separators and filter vessels is 6–12 weeks depending on vessel size, material, internals, certification, inspection, and documentation. We can prepare export packaging and support worldwide shipment by sea, truck, or multimodal transport according to project location and delivery terms.