3160245HPC Air/Oil Separator (Kaeser 645790 Equivalent) for Kaeser M70 Screw Compressor

1. Purpose and Operating Principle

The element is installed inside the compressor’s oil separator tank, after the primary gravitational oil separation stage, and performs three functions:

• coalesces the finest oil aerosol droplets in the compressed air stream into larger droplets, which drain back into the oil circuit through the scavenge (return) line;
• reduces residual oil content in the compressed air at the compressor outlet to compliant levels (typically a few ppm);
• ensures minimal flow resistance while maintaining high separation efficiency, which directly affects the compressor’s energy efficiency.

2. Technical Specifications

3. Design Features

1. Italian manufacturing by TGfilter. The brand specializes in filtration and separation elements for industrial compressor equipment, confirmed by a wide range of similar models.
2. Multi-layer coalescing filter media. Ensures progressive enlargement of oil droplets — from the finest aerosol to droplets that drain back into the oil sump under their own weight.
3. Flange with 8 mounting holes (E=8, F=13 mm, G=213.5 mm). Provides secure attachment of the element to the separator tank cover and even distribution of tightening force around the entire seal circumference.
4. Compact height (245 mm) with increased diameter (160/197 mm). Optimizes filtering surface area while maintaining mounting dimensions compatible with the original Kaeser M70 tank.
5. Flush-mounted cap (H2=0). Means the element’s top end cap does not protrude beyond the housing — important to consider when checking clearance to the separator tank cover.

4. Installation Recommendations

• Check element orientation before installation — airflow direction and the oil return (scavenge) tube must align with the tank’s mounting seat; installing the element upside down drastically reduces separation efficiency.
• Replace the oil return line O-ring at every installation — a worn or missing scavenge line seal leads to increased oil carryover even with a functioning filter element.
• Tighten the tank cover fasteners evenly, in a crisscross pattern, across all 8 holes (E=8) — uneven tightening deforms the sealing surface and causes gasket misalignment.
• Do not exceed the tightening torque specified by the compressor manufacturer for bolts passing through the F=13 mm holes — excessive force damages the tank cover’s threaded connections.
• Check the cleanliness of the scavenge line (oil return tube) before installing a new element — a clogged return line leads to increased pressure drop and premature element failure.
• After starting the compressor, check the pressure drop across the separator (via a differential pressure gauge, if installed) and confirm there are no leaks around the tank cover perimeter.

5. Analogues and Comparison

The 3160245HPC is a direct equivalent of the original Kaeser 645790 separator element, used in the oil separator tanks of Kaeser M70 series screw compressors. In connection dimensions (A160/C197/D97/H245, 8×⌀13 mm flange on a ⌀213.5 mm bolt circle) and functionality, the element is fully interchangeable with the Kaeser original.

Besides the Kaeser original, the 3160245HPC is comparable in size to separator elements from other manufacturers, including Mann+Hummel, Donaldson, and Parker Hiross lines.

When selecting an equivalent, always verify:

• the original Kaeser 645790 part number — the primary reference for a fast and accurate replacement;
• the flange connection dimensions (hole diameter, number of holes, and bolt circle diameter) — a mismatch in any of these parameters prevents correct installation;
• overall height and diameters (A/C/D/H) — critical for correct seating inside your specific separator tank housing;
• separation efficiency (residual oil content in ppm) — an important parameter for compressors used in food or medical applications.

If you are selecting a replacement for a specific compressor serial number, send us the markings from the removed element — we’ll verify compatibility before shipping.

6. Common Installation Mistakes

• Installing the element upside down — drastically reduces separation efficiency and leads to increased oil carryover into the compressed air network.
• Reusing the old scavenge line O-ring — a frequent cause of increased oil consumption after replacing the element.
• Uneven tightening of the tank cover fasteners — deforms the sealing surface and causes compressed air and oil leaks.
• Ignoring a clogged oil return line — leads to premature failure of the new element even when correctly installed.
• Replacing the element only on a fixed schedule without monitoring pressure drop — under high dust conditions or intensive operation, the element may reach the end of its service life earlier than the planned interval.

7. Practical Applications

3160245HPC series separator elements are used in the following areas:

• Industrial compressor stations — on Kaeser screw airends and compatible models.
• Food production — compressor installations for bottling and packaging lines where low oil content in the air is critical.
• Medical and dental equipment — compressor stations with strict compressed air purity requirements.
• Compressor equipment service centers — as a consumable for scheduled maintenance.
• Paint and coating production — spray-painting lines sensitive to oil aerosol in the air.

8. Expert Opinion

Vitali Boluchevski, Lead Engineer at Acvatron SRL (18 years of experience):

“The separator element is one of the most underrated components of a screw compressor: as long as it’s working, nobody thinks about it, but once it wears out, oil consumption spikes and system pressure drops. The 3160245HPC is a solid alternative to the original Kaeser 645790 at a reasonable price. The key thing when replacing it is not to forget the oil return line O-ring: it’s the part most often skipped, yet it’s exactly what ensures separated oil returns to the circuit instead of staying in the air. I recommend monitoring pressure drop across the separator if your compressor has the corresponding gauge installed — it’s a more reliable indicator of the element’s actual condition than operating hours alone.”

9. Frequently Asked Questions

1. Which original Kaeser part number does the 3160245HPC element correspond to? The 3160245HPC is the equivalent of the original Kaeser 645790 separator element, used in the oil separator tanks of Kaeser M70 series compressors.

2. Does this element fit my specific Kaeser M70 model? If you already have an element marked 645790 installed, the 3160245HPC fits directly. If in doubt, send us the markings from the removed element or the compressor’s serial number — we’ll confirm the exact match before you order.

3. How often should the separator element be replaced? ⚠️ The exact interval depends on operating conditions, air dust levels, and oil quality used — we recommend following your compressor manufacturer’s schedule or the readings of a differential pressure gauge, if installed. Contact us to determine the recommended interval for your model.

4. How do I know when the element needs replacing — by time or by pressure drop? The most reliable indicator is a rise in pressure drop across the separator (if your compressor has a differential pressure gauge). Scheduled replacement by operating hours is used as a safety-margin interval when pressure monitoring isn’t available.

5. Does the oil return line O-ring need to be replaced when changing the element? Yes, always. A worn or missing scavenge line seal is one of the most common causes of increased oil carryover after installing a new element.

6. Does the installation orientation of the element affect its performance? Yes, critically. Airflow direction and the position of the oil return tube must match the tank’s mounting seat — installing the element upside down drastically reduces separation efficiency.

7. Can this element be used on compressors from other brands? Yes, if the connection dimensions (A/C/D/H and flange parameters E/F/G) match your tank’s mounting seat. We recommend checking the markings on the removed element before ordering.