The right Hankison filter depends on what needs to come out of the air: solid particles, liquid water, oil aerosols, or oil vapor. Those contaminants require different treatment methods. A fine coalescing filter won’t replace an air dryer, and a particulate filter won’t remove oil vapor.
For buyers evaluating Hankison compressed air filtration, matching filters to air quality needs starts at the equipment using the air—not with the filter housing’s pipe connection. Define the required air quality, check actual operating conditions, then select the appropriate filtration stages and capacity.
That approach helps avoid two common purchasing mistakes: buying filtration that doesn’t address the contamination problem, or treating the entire plant to a standard only one process needs.
Start With the Air Quality Required at the Machine
“Clean, dry air” isn’t a complete specification. A maintenance team may mean no visible water at a blowgun. A process engineer may mean documented limits for particles, moisture, and total oil at a production connection.
Before choosing Hankison filtration, get the equipment manufacturer’s air requirements or the process specification. Where ISO 8573-1 classes are specified, identify the separate requirements for particles, water, and oil. The oil requirement includes liquid oil, aerosols, and vapor—not just what a coalescing element captures.
Also identify where the requirement applies. Air leaving the treatment equipment can pick up rust, pipe scale, or contamination from older distribution piping before reaching the machine.
General plant tools: Start with the tool manufacturer’s requirements for moisture, particles, and lubrication.
CNC equipment and instrumentation: Check requirements for controls, valves, and other air-operated components separately.
Painting and finishing: Determine acceptable moisture and oil levels; contamination can affect the finish even when pressure looks normal.
Product-contact applications: Use the process quality requirements and appropriate testing rather than assuming a particular filter grade makes the air suitable.
Breathing air is a separate application. Ordinary industrial filtration should never be treated as proof that compressed air is safe to breathe.
Match the Hankison Filter Type to the Contaminant
Evaluate the current Hankison product literature for the proposed series and grade. Removal performance, rated conditions, required upstream treatment, and element compatibility must come from the specific product documentation.
Bulk Liquid Separation: Remove Water Before It Overloads Treatment
A bulk liquid separator removes entrained liquid droplets, commonly after an aftercooler or at another location where water collects. It reduces the liquid load reaching downstream equipment, but it doesn’t remove water vapor or establish a pressure dew point.
The drain is part of the treatment function. A separator with a blocked drain can collect water and then allow it to carry downstream.
Particulate Filtration: Control Solid Contamination
Particulate filters capture solids such as rust, pipe scale, and desiccant dust. They’re useful where the concern is debris reaching valves, instruments, or production equipment.
Don’t compare filters by a micron number alone. Ask what removal efficiency that rating represents and under what test conditions. A dry particulate filter and a coalescing filter can have different jobs even when their descriptions contain similar particle-size language.
Coalescing Filtration: Remove Liquid Aerosols
Coalescing elements capture fine liquid aerosols and combine them into larger droplets that drain from the housing. Depending on the selected grade, they also capture fine solid particles.
These filters are commonly used to reduce oil and water aerosols and protect downstream treatment. However, coalescing filtration does not remove water vapor or provide oil-vapor removal. Air can pass through a functioning coalescing filter and still produce condensation when it cools farther downstream.
Adsorption Filtration: Address Oil Vapor
Where the application requires oil-vapor reduction, an appropriate adsorption stage—often using activated carbon—may be needed after upstream treatment.
This stage shouldn’t receive uncontrolled liquid water or oil aerosols. Its useful life depends on contaminant loading, temperature, operating hours, and the selected equipment. Low differential pressure doesn’t prove that the adsorption media still has useful capacity.
Build a Treatment Sequence, Not Just a Filter Stack
A practical treatment arrangement assigns each component a job. Bulk separation handles liquid loading. Coalescing filtration addresses aerosols. The dryer controls water vapor. Particulate filtration captures solids, and adsorption handles oil vapor where required.
The order depends on the dryer technology and manufacturer instructions. Desiccant dryers commonly need upstream coalescing protection and downstream particulate filtration to capture desiccant dust. Refrigerated dryer arrangements vary; confirm the recommended inlet and outlet filtration for the selected equipment.
Avoid installing several fine filters simply because cleaner air sounds better. Unnecessary stages add pressure drop, element costs, drains, and maintenance points without necessarily improving the contaminant level that matters.
For many plants, central treatment can serve general production while a dedicated branch receives finer treatment. Point-of-use filtration can also address contamination introduced by distribution piping. Keep tool lubricators off branches supplying processes that require low-oil air.
Size for Actual Flow and Pressure
Matching the filter connection to the existing pipe size isn’t a sizing method. Neither is selecting a housing solely from compressor horsepower.
Review these conditions before choosing a Hankison housing and element combination:
Peak flow through that filter: Use simultaneous demand, not just average consumption. Confirm the basis of any quoted CFM rating.
Lowest operating pressure: Use the manufacturer’s pressure correction factors rather than assuming catalog capacity applies at every pressure.
Inlet temperature: Check both equipment limits and effects on treatment performance, particularly oil-vapor adsorption.
Contaminant loading: Heavy liquid or solid loading may require better upstream separation or prefiltration.
Pressure-drop allowance: Review clean-element loss and the manufacturer’s replacement guidance while preserving adequate machine inlet pressure.
Expansion plans: Account for identified additions without selecting an arbitrarily oversized assembly.
Storage location matters, too. A downstream receiver may supply brief demand spikes differently from a receiver located ahead of the filter. Size around the flow that actually crosses the element.
If pressure is satisfactory in the compressor room but low at production equipment, measure losses across filters and other components during peak demand. Raising compressor discharge pressure can hide a restriction without fixing it.
A Tennessee Example: Water at a New Finishing Station
Consider a West Tennessee manufacturer adding a finishing station during hot, humid weather. Water appears at the station, and purchasing is asked to order a finer Hankison filter.
Before choosing an element, maintenance should check dryer loading, inlet temperature, separator drains, and the temperature of the downstream piping. The added production demand may have pushed the dryer beyond its capacity under actual operating conditions.
If water vapor passes through the dryer and condenses in a cooler branch line, a finer coalescing filter won’t correct the underlying dew point problem. If liquid is already carrying through a separator because its drain failed, that requires a different repair.
Once moisture control is restored, the finishing process may still need coalescing and oil-vapor treatment. Those selections should follow the finish requirements, not the assumption that every visible defect calls for a finer element.
Compare Quotes and Plan Maintenance Together
A useful Hankison filtration quote should identify the housing, element grade, rated performance conditions, sizing corrections, expected pressure drop, drain arrangement, and required upstream treatment. Ask about replacement-element availability and service clearance before approving the installation.
Provide Gordon Air Compressor with operating pressure, peak airflow, inlet temperature, dryer type, existing filter information, and the application’s air quality requirement. Photos of nameplates and a simple treatment-system sketch can prevent confusion about what’s already installed.
For maintenance, track differential pressure under comparable flow conditions and follow the manufacturer’s replacement schedule. Differential pressure is useful for identifying restriction, but it doesn’t verify outlet air quality or detect every damaged element.
Check drains regularly. Isolate and depressurize housings before service, following site procedures and manufacturer instructions. Where air quality affects product acceptance, verify it through appropriate sampling at the required location.
Bottom Line
Select Hankison filtration by contaminant, required outlet quality, and actual operating conditions. Confirm that the dryer handles moisture vapor, that drains remove collected liquids, and that the filter arrangement delivers sufficient pressure during peak demand.
Gordon Air Compressor can help Tennessee facilities evaluate Hankison filter options and distinguish a filtration requirement from a dryer, drainage, or distribution problem.
Before ordering, bring your filter information and application requirements to Gordon Air Compressor. A review can help narrow the selection to equipment that fits the job.
Gordon Air Compressor
706 Scott Street
Memphis, TN 38112
Sales and Service: 901-327-1327
Emergency Service: 901-482-5925
