Product
Ingersoll Rand 99273906 Air Filter Element | M37 Compressor Intake
Genuine Ingersoll Rand 99273906 air filter element for M37 rotary screw compressors, 270 mm OD x 120 mm H, 2–10 μm filtration, ~1.3 m² media area. Export-ready OEM supply with model and part-number cross-checking.
- Export packaging & documentation support
- OEM / ODM customization available
- Sample and bulk order workflow
Ingersoll Rand 99273906 Air Filter Element for M37 Compressors
Product Overview
99273906 is the intake air filter element for the Ingersoll Rand M37 rotary screw air compressor. It sits inside the air filter housing at the compressor intake, upstream of the inlet valve, and acts as the first filtration barrier for the entire compressed air system.
As the machine draws in ambient air, dust, grit, fibers, water mist and oil mist are captured by the filter media before reaching the airend — surface filtration intercepts larger particles while depth filtration retains finer ones. Only clean air is allowed into the rotor meshing zone.
The condition of this element directly affects airend service life. Unfiltered air entering the screw airend accelerates rotor and bearing wear and contaminates the downstream oil separator, oil filter and lubricant, shortening all three at once. A heavily clogged element restricts intake volume, reducing discharge capacity and raising energy consumption; in extreme cases oil carryover can cause the airend to seize. Replacing the air filter on schedule is the lowest-cost protection measure for the airend.
Key specifications at a glance
| Item | Value |
|---|---|
| Part number | 99273906 |
| Description | Air Filter Element |
| Applicable model | Ingersoll Rand M37 rotary screw compressor |
| Unit discharge capacity | 6 m³/min @ 0.7 MPa |
| Element outer diameter | 270 mm |
| Element height | 120 mm |
| Effective filtration area | Approx. 1.3 m² |
| Filtration rating | 2–10 μm |
| Filtration efficiency | ≥98% for particles ≥5 μm |
| Initial pressure drop | Approx. 0.5–1.0 kPa |
| Alarm differential pressure | 6.0–6.5 kPa |
| Recommended replacement interval | Approx. 2,000 hours (adjust to operating conditions) |
Basic Parameters
| Parameter | Detail |
|---|---|
| Part Number | 99273906 |
| Brand | Ingersoll Rand |
| Product name | Air Filter Element |
| Product category | Intake filtration (air filter) |
| Applicable model | M37 rotary screw air compressor (see Section 6) |
| Unit discharge capacity | 6 m³/min @ 0.7 MPa |
| Installation position | Inside the intake air filter assembly, upstream of the inlet valve |
| Replacement interval | Approx. 2,000 hours |
Technical Specifications
1. Filtration performance
| Parameter | Value / Notes | Data basis |
|---|---|---|
| Filtration rating | 2–10 μm | Industry value (published figures range 2–10, 3–12, 5–10 and 10–15 μm; mainstream overlap taken) |
| Filtration efficiency | ≥98% for particles ≥5 μm | Industry value |
| Filter class | HVAC filter classes (EN 779 G/M/F) do not apply; air filter elements are characterised per ISO 5011 by efficiency, intake resistance and dust holding capacity | Technical note |
| Dust holding capacity | Approx. 380 g | Estimated (effective area 1.3 m² × typical 300 g/m² for wood-pulp filter paper) |
| Beta ratio (β value) | Not applicable to air filter elements | See note below |
Note on beta ratio: β values belong to hydraulic and lubricating oil filters, determined by the ISO 16889 multi-pass test, and describe the filtration ratio at given particle sizes. Air filter elements are not rated by β value; they are evaluated per ISO 5011 using filtration efficiency + intake resistance + dust holding capacity. If a β value appears on an air filter datasheet, it has usually been copied in error from a hydraulic filter specification.
2. Flow and resistance
| Parameter | Value / Notes | Data basis |
|---|---|---|
| Rated air flow | Matched to M37 unit capacity of 6 m³/min @ 0.7 MPa | Multiple sources (unit parameters) |
| Filtration face velocity | Approx. 0.077 m/s | Estimated (6 m³/min ÷ 1.3 m², within the normal 0.05–0.15 m/s range for air filters) |
| Initial pressure drop | Approx. 0.5–1.0 kPa | Estimated from face velocity and wood-pulp paper resistance characteristics |
| Operating differential pressure range | Approx. 1.0–6.0 kPa | Estimated across the full range from new-element resistance to alarm resistance |
| Alarm / final resistance | 6.0–6.5 kPa | Estimated from the unit's air filter differential pressure indicator setting; refer to the machine for the exact value |
| Pressure drop vs. energy | Each 1 kPa rise in intake resistance increases unit energy consumption by approx. 1% | Estimated; calculation shown below |
Quantified relationship between pressure drop and energy (estimated)
Based on an M37 discharge pressure of 0.7 MPa (gauge) and atmospheric pressure of 101.3 kPa, intake resistance raises the compression ratio:
| Intake resistance | Compression ratio | Relative energy increase vs. baseline |
|---|---|---|
| 0 kPa (new element) | 7.91 | Baseline |
| 2 kPa | 8.07 | +2.0% |
| 4 kPa | 8.24 | +4.1% |
| 6 kPa (near alarm) | 8.41 | +6.3% |
Engineering implication: as an element progresses from new to alarm condition (0 → 6 kPa), unit energy consumption rises by roughly 6% over that period. On a 37 kW unit running 6,000 hours per year, this represents sustained excess power draw during the latter part of the element's life. The money saved by continuing to run a clogged element is far less than the extra electricity cost — this is the engineering rationale behind the factory-set differential pressure alarm.
3. Dimensions and installation
| Parameter | Value / Notes | Data basis |
|---|---|---|
| Dimensions | 270 mm OD × 120 mm height | Consistent across multiple sources |
| Construction | Pleated (folded filter paper wrap) | Industry value |
| Effective filtration area | Approx. 1.3 m² | Estimated (based on 270 mm OD / 200 mm ID / 35 mm pleat depth / approx. 154 pleats; approx. 1.7 m² if ID is 165 mm) |
| Number of pleats | Approx. 150 | Estimated |
| Pleat spacing | Approx. 4.8 mm | Estimated (mean circumference 738 mm ÷ 150 pleats) |
| Mounting interface | End-cap located, matched to the M37 air filter assembly | Based on model compatibility |
| Sealing method | Face seal (axial compression) | Estimated (common design for this element type; confirm against the actual part) |
Procurement note: when cross-checking a replacement, 270 mm OD and 120 mm height are the two most direct dimensions to compare. The related ML37 / MU37 models use 39588777 (130 mm OD × 250 mm height) — the size difference is substantial and the two are not interchangeable.
4. Material composition
| Parameter | Value / Notes | Data basis |
|---|---|---|
| Filter media | Imported wood-pulp filter paper (commonly US HV or Korean Ahlstrom paper in the industry) | Industry value |
| Media basis weight | Approx. 130 g/m² | Estimated (midpoint of the typical 100–150 g/m² range for air filter paper) |
| Inner / outer support | Galvanised steel perforated cage, approx. 0.6 mm sheet thickness, open area ≥45% | Estimated (standard practice for comparable products) |
| End caps | Metal end caps (galvanised steel) with polyurethane adhesive | Estimated (no plastic end caps specified for this series) |
| Seal | Nitrile rubber (NBR) seal ring | Estimated (standard material for compressor intake parts; oil and temperature resistant, −30 to +100 °C) |
| Bonding layer | Polyurethane (PU) hot-melt adhesive | Estimated (standard process for bonding media to end caps and cage) |
5. Operating tolerance
| Parameter | Value / Notes | Data basis |
|---|---|---|
| Operating temperature | −10 to +100 °C | Industry value |
| Relative humidity | ≤80% RH, no condensation | Estimated (wood-pulp paper loses strength and efficiency when damp; condensation conditions require upstream moisture removal) |
| Bursting strength | Filter paper bursting strength approx. 200–400 kPa (per ISO 2758 paper bursting strength test) | Estimated (typical range for air filter paper) |
| Collapse resistance | Element designed for differential pressure ≥10 kPa | Estimated (approx. 50% safety margin over the 6.5 kPa alarm value) |
| Special functions | No flame-retardant, anti-static or moisture-proof ratings specified for this part number | — |
6. Service life and maintenance
| Parameter | Value / Notes | Data basis |
|---|---|---|
| Service life | Approx. 2,000 hours | Industry value (consistent across multiple sources) |
| Actual replacement interval | Shorten to under 1,000 hours in dusty, sandy or humid environments; follow the differential pressure alarm | Engineering recommendation |
| Storage shelf life | Approx. 2–3 years (unopened, dry and ventilated conditions) | Estimated (typical validity for filter paper and adhesives under controlled storage; moisture or direct sunlight will shorten it significantly) |
7. Applicable standards
| Item | Detail |
|---|---|
| Product standard | ISO 5011 (inlet air cleaning equipment for internal combustion engines and compressors — performance testing), evaluated by filtration efficiency, intake resistance and dust holding capacity |
| Frequently cited test standards | ISO 2941 / 2942 / 2943 / 3723 / 3724 / 3968 |
| Standard applicability note | The ISO 29xx / 37xx series above are in fact general test methods for hydraulic fluid power filter elements (collapse/burst rating, structural integrity, material compatibility, axial load, flow fatigue, pressure drop vs. flow). If a supplier can only provide hydraulic filter standards, request ISO 5011 data or the original manufacturer specification. |
Standard Maintenance and Installation Steps
One person can complete the job; working time is approximately 20–30 minutes.
Stop the machine, isolate power and release pressure
Press the emergency stop or stop button, disconnect the main power and apply lockout/tagout. Open the receiver tank drain valve to release system pressure and wait until the pressure gauge on the oil separator tank reads zero. Criterion: gauge reads 0 and no residual air flow is audible.Locate and open the air filter housing
The M37 filter assembly is at the intake end of the unit. Loosen the housing clamp or end-cap bolts and remove the end cap. Criterion: end cap is not deformed and the clamp is not seized; if the clamp is seized, free it before proceeding.Remove the old element and inspect its condition
Pull the old element straight out and examine the dust distribution and media condition. Criterion: if the media is torn, punctured, the end cap is debonded or the sealing face is flattened, replace immediately even if the interval has not been reached; a black oily film on the outer surface indicates abnormal oil mist in the intake and the upstream environment should be checked.Thoroughly clean the housing interior
Wipe the inner walls and base with a lint-free cloth. Do not blow compressed air hard into the housing interior (this drives dust into the intake passage). Criterion: no loose dust on the inner walls and a flat, debris-free sealing face.Verify the new element
Compare old and new parts: 270 mm OD, 120 mm height, intact face seal with no gaps, undamaged media. Criterion: all three dimensions and the visual check pass; if any item does not match, do not install — re-check the part number.Fit the new element and refit the end cap
Place the new element vertically into the housing, confirm it is fully seated at the base and the sealing face is in contact with no trapped material. Refit the end cap and tighten the clamp or bolts evenly in a diagonal sequence. Criterion: even gap between end cap and housing with no visible skew.Start-up check
Restore power and run the unit for 5–10 minutes. Criterion: no abnormal whistling or intake noise at the intake (unusual noise usually means the seal is not compressed or the element is not seated); the air filter differential pressure indicator should be in the green zone.
The one unbreakable rule: never start the unit before the element is seated. Running with no element or with an uncompressed seal lets unfiltered air straight into the airend, which can cause irreversible wear in a short time.
Frequently Asked Questions
Are 99273906 and 39588777 interchangeable?
No. 39588777 is for ML37 / MU37 models with a 130 mm OD and 250 mm height; 99273906 is for M37 with a 270 mm OD and 120 mm height. The sizes differ by more than a factor of two and will not physically fit the same housing. Always cross-check by both model and part number when ordering.
How often should it be replaced?
Approximately 2,000 hours under standard conditions. This is not a hard deadline: in high-dust environments (cement, foundry, woodworking, mining sites) shorten to under 1,000 hours; in clean environments with low running hours it may be extended. The most reliable method is to follow the air filter differential pressure indicator and replace when it reaches the alarm position.
What happens if it is not replaced?
Failure propagates through the system and has a clear economic cost. As the element loads with dust, intake resistance rises; based on compression ratio calculations, resistance increasing from 0 to 6 kPa raises unit energy consumption by approximately 6.3%. Once the media tears or the seal fails, unfiltered air enters the airend directly and dust contaminates the screw rotors, bearings, oil separator, oil filter and lubricant simultaneously — repair cost escalates from the price of one filter to the scale of an airend overhaul.
How do I know it is time to replace?
Three signals: first, the differential pressure indicator enters the alarm zone (approx. 6.0–6.5 kPa); second, on visual inspection after shutdown the media surface is fully covered with dust and the original pleat pattern is no longer visible; third, the unit shows reduced discharge capacity with rising current or energy consumption. Any one signal means replacement is due.
Can the element be cleaned and reused?
Not recommended. This is a pleated paper element designed as a single-use part. Blowing compressed air from the inside out only removes surface dust; fine particles trapped in the depth of the media cannot be cleared, and the air pressure can easily fracture the paper fibers or distort the pleat spacing, creating invisible channels that let unfiltered air pass. Reusing a cleaned element is a "looks clean, actually failed" condition with more risk than benefit.
What else should be checked when replacing the air filter?
We recommend also checking: whether the air filter differential pressure indicator is still responsive (does it return correctly after being pressed to reset), whether the intake hose is cracked or loose, whether the housing seal ring is aged, and whether the inlet valve operates correctly. These parts work together with the air filter; replacing only the element without checking the surrounding components can quickly lead to intake problems again.
Is this element a genuine part?
99273906 as described on this page is the Ingersoll Rand original part number. When ordering, verify against the part number itself — the part number is the only identifier that cannot be confused. Do not order based solely on "fits M37" or visual similarity.
Do M37 and other M-series models use the same air filter?
No. Air filter specifications differ across the Ingersoll Rand M series: M22 uses 39588470 (130 mm OD), M37 uses 99273906 (270 mm OD), M55 uses 39708466 (278 mm OD) and ML37 uses 39588777. Being in the same series does not mean the same element — verify model by model.
What is the most error-prone step during installation?
Two things: first, trapping material on the sealing face or compressing the end cap before the element is fully seated, causing a poor seal and air leakage; second, tightening end-cap bolts in a one-sided sequence, causing uneven load and skew. The correct method is to confirm seating first, then tighten evenly in a diagonal cross pattern in several passes.
Are there storage requirements for a new element?
Yes. Filter paper absorbs moisture, swells and deforms, reducing filtration efficiency, and the metal cage will corrode if damp. Store on indoor shelving in a dry, ventilated area, away from walls and floors, and away from water and oil. Use unopened stock within approximately 2–3 years. Follow first-in, first-out for unopened packaging and avoid long-term stockpiling.
Compatible Models
| No. | Model | Unit discharge capacity | Air filter part number | Element OD × height |
|---|---|---|---|---|
| 1 | M37 | 6 m³/min @ 0.7 MPa | 99273906 | 270 mm × 120 mm |
| 2 | M22 | 3 m³/min @ 0.7 MPa | 39588470 | 130 mm × 151 mm |
| 3 | M55 | 10 m³/min @ 0.7 MPa | 39708466 | 278 mm × 125 mm |
| 4 | ML37 / MU37 | 6 m³/min @ 0.7 MPa | 39588777 | 130 mm × 250 mm |
| 5 | 30S | 3 m³/min @ 0.7 MPa | 42855429 | 130 mm × 123 mm |
| 6 | 50S | 6 m³/min @ 0.7 MPa | 42855411 | 216 mm × 318 mm |
| 7 | 75S | 10 m³/min @ 0.7 MPa | 42855403 | 278 mm × 251 mm |
How to read this table
- The product on this page, 99273906, corresponds to row 1, M37. The other rows are provided as cross-references within the same series to help you avoid a wrong purchase.
- Row 4 (ML37 / MU37) and row 1 (M37) both have a discharge capacity of 6 m³/min, but the air filter part numbers and dimensions are completely different — the same discharge capacity does not mean an interchangeable element. This is the most easily confused point in this series.
- If the model on your unit nameplate is not listed above, please provide a photo of the nameplate and the full model number. We will confirm by reverse lookup against the part number before you order.
Note on model generations
The Ingersoll Rand M37 exists in different production generations. The 99273906 described on this page is the intake filter for earlier M37 models. Newer M37-75 series units (covered by the SL/SM37-75KW operation and parts manual) use a different part number system in their parts manuals. If your unit is a recent build, verify against the parts manual supplied with the machine, or contact us to confirm by unit serial number. In practice, the most reliable confirmation is still to read the part number from the old element itself.
Related Components
Seven components in the M37 intake and lubrication system are maintained on the same cycle as the air filter. They are listed below by location, function and inspection point. For specific part numbers, refer to the unit parts manual.
| Component | Location | Function | Inspection point |
|---|---|---|---|
| Oil filter element | Main oil circuit, between cooler and airend | Removes wear debris and sludge from lubricant, protecting bearings and rotors | Replace together with the air filter; after replacement check the housing sealing face for oil seepage |
| Oil separator element | Inside the oil separator tank | Separates oil mist from compressed air and returns oil, controlling oil carryover in the discharge | When replacing, also check the oil return line for blockage (poor return directly causes excessive oil carryover) |
| Air filter differential pressure indicator | On the air filter assembly | Indicates element clogging and signals replacement timing | Should return correctly after being pressed to reset; if the reading never moves it has failed and should be replaced |
| Coolant filter element | Coolant circuit, between cooler and filter | Keeps coolant clean and prevents scale and wear debris deposits | Replace together with the oil filter element |
| Thermostatic control valve element | Between cooler and filter | Controls coolant flow through the cooler, maintaining airend operating temperature | If the unit runs cold for long periods or triggers high-temperature alarms, check the thermostatic valve first |
| Breather filter | On the oil separator tank | Balances tank pressure and prevents external dust entering the oil circuit | Check on the same cycle as the air filter; shorten the interval in dusty environments |
| Intake hose and housing seal ring | Between the air filter assembly and the airend | Ensures the intake path is leak-free with no unfiltered air bypass | Check for cracks, ageing and loose clamps — bypass leakage is as harmful as running without an element |
Recommended combined replacement: in dusty sites we recommend replacing the air filter, oil filter element and oil separator element together to avoid staggered maintenance cycles and repeated downtime. The coolant filter element and thermostatic valve element follow their own separate intervals.