Product
Ingersoll Rand 99273906 Air Filter Element | M37 Compressor Intake
Genuine Ingersoll Rand 99273906 air filter element for M37 screw compressors. 270 mm OD × 120 mm height, 2–10 μm filtration, ~1.3 m² media area, ~2000-hour service interval. Export-ready with full part-number traceability.
- Export packaging & documentation support
- OEM / ODM customization available
- Sample and bulk order workflow
Product Overview
99273906 is the intake air filter element for the Ingersoll Rand M37 screw air compressor. It is mounted inside the air filter housing at the compressor intake, upstream of the inlet valve, forming 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 intercepted by the media before reaching the airend — surface filtration captures coarse particles while depth filtration retains finer contaminants. Only clean air is allowed into the rotor meshing zone.
Element condition directly affects airend service life. Hard particles entering the screw airend accelerate rotor and bearing wear and simultaneously contaminate the downstream separator element, oil filter and lubricant, shortening the life of all three. When the element is heavily clogged, intake volume drops, discharge capacity falls and energy consumption rises; in extreme cases oil carry-over can lead to airend seizure. Timely air filter replacement is therefore the lowest-cost protection measure for the airend.
Core Specifications
| Item | Value |
|---|---|
| Part number | 99273906 |
| Product name | Air Filter Element |
| Applicable model | Ingersoll Rand M37 screw compressor |
| Machine 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 resistance | 6.0–6.5 kPa |
| Recommended service interval | Approx. 2000 hours (adjust to operating conditions) |
Technical Parameters
Filtration Performance
| Parameter | Value / Notes | Data basis |
|---|---|---|
| Filtration rating | 2–10 μm | Industry range (published figures vary between 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 to ISO 5011 by filtration efficiency, intake resistance and dust holding capacity. | Technical note |
| Dust holding capacity | Approx. 380 g | Estimated (1.3 m² effective area × 300 g/m² typical for wood-pulp filter paper) |
| Beta ratio (β value) | Not applicable to air filter elements | See note below |
Note on β value: the beta ratio is a hydraulic and lubricating oil filter metric determined by the ISO 16889 multi-pass test. Air filter elements are not characterised by β value; they are evaluated to ISO 5011 using filtration efficiency, intake resistance and dust holding capacity. A β value appearing in an air filter specification is usually copied in error from a hydraulic filter datasheet.
Flow and Resistance
| Parameter | Value / Notes | Data basis |
|---|---|---|
| Rated air flow | Matched to M37 discharge capacity of 6 m³/min @ 0.7 MPa | Machine data |
| 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 media resistance characteristics |
| Operating differential range | Approx. 1.0–6.0 kPa | Estimated (from new-element initial resistance to alarm resistance) |
| Alarm / final resistance | 6.0–6.5 kPa | Estimated per the machine air-filter differential indicator setting; refer to the machine manual |
| Pressure drop vs. energy | Each 1 kPa increase in intake resistance raises machine energy consumption by approx. 1% | Estimated; calculation below |
Pressure drop and energy consumption (estimated). Taking M37 discharge pressure of 0.7 MPa (gauge) and atmospheric pressure of 101.3 kPa as the baseline, intake resistance raises the compression ratio:
| Intake resistance | Compression ratio | Relative energy increase |
|---|---|---|
| 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 runs from new to alarm condition (0 → 6 kPa), machine energy consumption rises by roughly 6%. On a 37 kW machine running 6000 hours per year, this represents sustained excess power draw during the latter part of element life. The saving from running a clogged element is far outweighed by the additional electricity cost — the engineering rationale behind the factory differential-pressure alarm.
Dimensions and Installation
| Parameter | Value / Notes | Data basis |
|---|---|---|
| Overall dimensions | 270 mm OD × 120 mm height | Consistent across sources |
| Construction | Pleated (wound filter paper) | Industry standard |
| Effective filtration area | Approx. 1.3 m² | Estimated (270 mm OD / 200 mm ID / 35 mm pleat depth / ~154 pleats; approx. 1.7 m² if ID is 165 mm) |
| Pleat count | Approx. 150 | Estimated |
| Pleat spacing | Approx. 4.8 mm | Estimated (738 mm average circumference ÷ 150 pleats) |
| Mounting interface | End-cap located, matched to the M37 air filter assembly | Machine fitment |
| Sealing | Face seal (axial compression) | Estimated; common for this element type — confirm against the physical part |
Procurement tip: when cross-checking a replacement, 270 mm OD and 120 mm height are the two most direct comparison dimensions. The related ML37 / MU37 models use 39588777 (130 mm OD × 250 mm height) — a very large dimensional difference, and the two are not interchangeable.
Materials
| Parameter | Value / Notes | Data basis |
|---|---|---|
| Filter media | Imported wood-pulp filter paper (industry-common US HV or Ahlstrom media) | Industry standard |
| Media grammage | Approx. 130 g/m² | Estimated (mid-point of the typical 100–150 g/m² range for air filter paper) |
| Inner and outer support | Galvanised steel perforated cage, approx. 0.6 mm thickness, ≥45% open area | Estimated (common practice for comparable products) |
| End caps | Metal end caps (galvanised steel) with polyurethane bonding | Estimated (no plastic end caps specified for this series) |
| Seal | NBR (nitrile) seal ring | Estimated; standard for compressor intake parts, oil and temperature resistant −30 to +100 °C |
| Bonding | Polyurethane (PU) hot-melt adhesive | Estimated (common process for bonding media to end caps and cage) |
Operating Tolerance
| Parameter | Value / Notes | Data basis |
|---|---|---|
| Operating temperature | −10 to +100 °C | Industry value |
| Relative humidity | ≤80% RH, no condensation | Estimated (wood-pulp media loses strength and efficiency when damp; upstream moisture removal is required in condensing conditions) |
| Bursting strength | Approx. 200–400 kPa (per ISO 2758 paper burst 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 rating specified for this part number | — |
Service Life and Maintenance
| Parameter | Value / Notes | Data basis |
|---|---|---|
| Service life | Approx. 2000 hours | Industry value (consistent across sources) |
| Actual replacement interval | Shorten to under 1000 hours in dusty, sandy or humid environments; follow the differential-pressure alarm | Engineering recommendation |
| Shelf life | Approx. 2–3 years (unopened, dry and ventilated storage) | Estimated (typical validity of media and adhesive under controlled storage; moisture or direct sunlight significantly shortens it) |
Applicable Standards
| Item | Content |
|---|---|
| Product standard | ISO 5011 (inlet air filters for internal combustion engines and compressors — performance testing), evaluated on filtration efficiency, intake resistance and dust holding capacity |
| Commonly 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, construction 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
One person can complete the job in approximately 20–30 minutes.
Shut down, isolate and depressurise. Press the emergency stop or shutdown button, disconnect the main power supply and apply lockout/tagout. Open the receiver tank drain valve to release system pressure and wait until the separator tank gauge reads zero. Criterion: gauge at 0 with no residual air flow noise.
Locate and open the air filter housing. On the M37 the filter assembly sits at the intake end of the machine. Release the housing clamp or end-cover bolts and remove the cover. Criterion: cover not deformed, clamp not seized; treat a seized clamp before removal.
Remove the old element and inspect its condition. Pull the element out vertically and examine dust distribution and media condition. Criterion: replace immediately if the media is torn, perforated, debonded from the end cap or the sealing face is flattened, even before the interval is reached. Black oily sludge on the outer surface indicates abnormal oil mist in the intake — check the upstream environment.
Clean the housing interior thoroughly. Wipe the inner wall and base with a lint-free cloth. Do not blow compressed air hard into the housing — this drives dust into the intake passage. Criterion: no loose dust on the inner wall, sealing face flat and free of debris.
Verify the new element. Compare old and new: 270 mm OD, 120 mm height, intact end-face seal with no gaps, undamaged media. Criterion: all three dimensions and the visual checks pass. If any item does not match, do not install — re-check the part number.
Fit the new element and refit the cover. Place the element vertically into the housing, confirm it is fully seated at the base and the sealing face contacts without trapped material. Refit the cover and tighten the clamp or bolts evenly in a diagonal sequence. Criterion: even gap between cover and housing, no visible skew.
Start-up check. Restore power and run the machine for 5–10 minutes. Criterion: no abnormal whistling or intake air noise (unusual noise usually means the seal is not compressed or the element is not seated); the air filter differential indicator should be in the green zone.
The one hard rule: never start the machine before the element is seated. Running with no element or an uncompressed seal allows unfiltered air straight into the airend and can cause irreversible wear in a short time.
FAQ
Are 99273906 and 39588777 interchangeable?
No. 39588777 fits ML37 / MU37 models with a 130 mm OD × 250 mm height element, while 99273906 fits the M37 with a 270 mm OD × 120 mm height element. The dimensions differ by more than a factor of two and will not fit the same housing. Always cross-check both model and part number when ordering.
How often should it be replaced?
Approximately 2000 hours under standard conditions. This is not a fixed deadline: in high-dust environments (cement, foundry, woodworking, mining sites) shorten it to under 1000 hours; in clean environments with low running hours it can be extended. The most reliable method is to follow the air filter differential indicator and replace at the alarm point.
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 the compression ratio calculation, energy consumption increases by roughly 6.3% as resistance goes from 0 to 6 kPa. If the media tears or the seal fails, unfiltered air enters the airend and dust contaminates the screw rotors, bearings, separator element, oil filter and lubricant simultaneously — repair cost escalates from the price of one element to the level of an airend overhaul.
How do I know it is time to replace?
Three signals: the differential indicator enters the alarm zone (approx. 6.0–6.5 kPa); visual inspection after shutdown shows the media surface completely covered with dust so the original pleat pattern is no longer visible; or the machine shows reduced discharge capacity with rising current/energy consumption. Replace on any one signal.
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 inside out only removes surface dust; fine particles trapped in the depth of the media cannot be cleared, and the air pressure easily fractures media fibres or deforms pleat spacing, creating invisible channels that let unfiltered air pass. A cleaned element that looks serviceable is often functionally failed — the risk outweighs the benefit.
What else should be checked when replacing the air filter?
Check the air filter differential indicator for correct response (does it return after reset), the intake hose for cracks or looseness, the housing seal ring for ageing, and the inlet valve for correct operation. These parts work together with the element; replacing only the element without checking the surrounding components often leads to repeat intake faults in a short time.
Is this a genuine part?
The 99273906 described on this page is an Ingersoll Rand original equipment part number. When ordering, confirm the part number itself — it is the only unambiguous identifier. Do not order solely on the basis of "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. The same series does not mean the same element — verify model by model.
What is the most common installation error?
Two: trapping material on the sealing face or pressing the cover down before the element is fully seated, causing a leak; and tightening cover bolts in a single-side sequence, which skews the cover. 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. Wood-pulp media swells and deforms when damp, reducing filtration efficiency, and the metal cage corrodes. Store on indoor shelving in a dry, ventilated area, off the floor and away from walls, water sources and oil contamination. Use within 2–3 years while unopened, following first-in-first-out. Long-term stockpiling is not recommended.
Compatible Machine Models
| No. | Model | Machine 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 the table
- The product on this page, 99273906, corresponds to row 1, M37. The other rows are provided for series comparison only, 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 — identical discharge capacity does not mean a shared element. This is the most easily confused point in this series.
- If your machine nameplate is not listed above, provide a photo of the nameplate and the full model number. We will confirm by reverse lookup from the part number before you order.
Note on machine generations. The Ingersoll Rand M37 exists in different production generations. The 99273906 described here is the intake filter for earlier M37 models. Newer M37-75 series machines (covered by the SL/SM37-75KW operation parts manual) use a different part number system. If your machine is a recent unit, verify against the parts manual supplied with the machine or contact us to confirm by machine serial number. In practice, the most reliable confirmation is still to read the part number from the old element itself.
Related Components
The M37 intake and lubrication system includes seven components maintained on a similar cycle to the air filter. They are listed below by location, function and inspection point. For specific part numbers, refer to the machine 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; check the housing sealing face for oil seepage after replacement |
| Separator element | Inside the separator tank | Separates oil mist from compressed air and returns oil, controlling oil carry-over | Check the oil return line for blockage at replacement (poor return directly causes excessive oil carry-over) |
| Air filter differential indicator | On the air filter assembly | Indicates element clogging and signals replacement timing | Should return correctly after reset; a reading that never moves indicates failure and should be replaced |
| Coolant filter element | Coolant circuit, between cooler and filter | Keeps coolant clean and prevents scale and debris build-up | Replace together with the oil filter element |
| Thermostatic control valve element | Between cooler and filter | Controls coolant flow through the cooler to maintain airend operating temperature | If the machine runs cold long-term or triggers high-temperature alarms, check the thermostatic valve first |
| Breather filter | On the separator tank | Balances tank pressure and prevents external dust entering the oil circuit | Inspect on the same cycle as the air filter; shorten the interval in dusty environments |
| Intake hose and housing seal ring | Between air filter assembly and airend | Ensures no leakage or unfiltered air bypass in the intake path | Check for cracks, ageing and loose clamps — bypass leakage is as harmful as running without an element |
Combined replacement recommendation: on dusty sites, replace the air filter, oil filter element and separator element together to avoid staggered maintenance intervals and repeated downtime. Schedule the coolant filter element and thermostatic valve element on their own cycles.