IMO® Three-Screw Pump Replacements: Factory-Direct Drop-In Equivalents
Trusted worldwide for turbine lubrication, burner fuel booster injection, and marine hydraulic circuits. Orbi Pump 3G and SN series triple screw pumps offer 1:1 interchangeable hydraulic geometry and casing dimensions with IMO® ACE, ACG, and ACF series. Built with ion-nitrided 38CrMoAlA screws and high-phosphorus wear-resistant alloy liners for whisper-quiet (<65 dBA) and pulsation-free fluid displacement.
IMO® Precision / Colfax Replacement Model Matrix
100% flange & footprint interchangeability
| OEM Model | Orbi Pump Equivalent | Flow (m³/h) | Pressure | Port / Flange | Speed | Action |
|---|---|---|---|---|---|---|
IMO ACE 025 (e.g. ACE 025L3) Direct drop-in equivalent for diesel feed and turbine lube oil loops. | Orbi Pump 3G25x2 | 0.6 ~ 1.8 (2.6 ~ 7.9 gpm) | 1.6 ~ 4.0 MPa (232 ~ 580 psi) | DN25 (1") Flange | 1450 ~ 2900 rpm | Specs → |
IMO ACE 032 (e.g. ACE 032N3) Direct equivalent for boiler burner fuel injection and marine auxiliaries. | Orbi Pump 3G32x2 | 1.2 ~ 3.6 (5.3 ~ 15.8 gpm) | 1.6 ~ 4.0 MPa (232 ~ 580 psi) | DN32 (1.25") Flange | 1450 ~ 2900 rpm | Specs → |
IMO ACE 038 (e.g. ACE 038K3) Standard high-pressure oil lubrication and hydraulic elevator service. | Orbi Pump 3G38x2 | 2.4 ~ 6.5 (10.5 ~ 28.6 gpm) | 1.6 ~ 4.0 MPa (232 ~ 580 psi) | DN40 (1.5") Flange | 1450 ~ 2900 rpm | Specs → |
IMO ACG 045 / 052 Modular casing with foot or flange mounting. Direct ACG equivalent. | Orbi Pump 3G50x2 / SN50 | 5.0 ~ 15.0 (22.0 ~ 66.0 gpm) | 1.6 ~ 2.5 MPa (232 ~ 362 psi) | DN50 (2") Flange | 1450 ~ 1750 rpm | Specs → |
IMO ACG 060 / 070 Heavy fuel oil transfer and large steam turbine bearings. | Orbi Pump 3G70x2 / SN70 | 12.0 ~ 30.0 (52.8 ~ 132.0 gpm) | 1.6 ~ 2.5 MPa (232 ~ 362 psi) | DN65 ~ DN80 Flange | 1450 ~ 1750 rpm | Specs → |
IMO ACF 080 / 090 / 100 High flow fuel oil bunkering, cargo oil transfer, and refinery loops. | Orbi Pump 3G100 / SN100 | 35.0 ~ 120.0 (154.0 ~ 528.0 gpm) | 1.6 MPa (232 psi) | DN100 ~ DN125 Flange | 960 ~ 1450 rpm | Specs → |
Mechanical Compatibility & Heavy-Duty Metallurgy
Precision Cycloidal Meshing Geometry
One power screw drives two idler screws without mechanical timing gears. Pure rolling tooth profile creates sealed axial chambers, eliminating fluid entrapment, turbulence, and shear.
Replaceable Cartridge Liner Design
The casing insert liner and screw set can be serviced or replaced without removing the pump body from the foundation or disconnecting pipeline flanges.
Hydraulically Balanced Axial Thrust
Integrated balance pistons neutralize hydraulic axial loads, delivering high reliability and extended bearing life under 24/7 continuous industrial duty.
Marine & Power Plant Specification
Built to GB/T 10886 and compliant with ISO and DIN 24297 standards. Available with marine classification survey documentation (CCS) upon request.
IMO® Precision / Colfax OEM vs Orbi Pump Replacement
| Comparison Point | IMO® Precision / Colfax (OEM) | Orbi Pump (Direct Factory) |
|---|---|---|
| Complete Pump Unit Price | OEM Premium ($3,800 – $16,000+ USD) | Direct Factory ($1,500 – $5,800 USD) — 50%–60% Savings |
| Lead Time for Standard Sizes | 12 to 20 Weeks | 5 to 12 Days (In-stock finished screw blanks) |
| Replacement Screw & Liner Set | Excessive cost, often delays maintenance | Drop-in screw/liner cartridges ready to dispatch |
Core Orbi Pump Series for IMO® Precision / Colfax Replacement

3G Triple Screw Pump
Industrial Screw Pumps • 3G
- models
- 10 (3G 20×4 → 3G 100×2)
- Flow Range
- 0.6 ~ 300 m³/h

SN Modular Triple Screw Pump
Industrial Screw Pumps • SN
- models
- 7 (SN-20 → SN-600)
- Flow Range
- 1.2 ~ 600 m³/h

2W.W Twin-Screw Multiphase Pump
Industrial Screw Pumps • 2W.W
- models
- 9 (2W.W-5 → 2W.W-1200)
- Flow Range
- 5 ~ 1200 m³/h
IMO® Precision / Colfax Replacement Engineering FAQs
Q: Can I replace an IMO ACE or ACG pump with a Orbi Pump 3G pump without repiping?
A: Yes. Our 3G series pumps strictly follow standard ISO and GB/T 10886 mounting geometries. The suction and discharge flange dimensions, flange drilling, and shaft extension align directly with IMO ACE and ACG models.
Q: What screw material is used to ensure wear resistance on heavy fuel oils?
A: Our screws are manufactured from 38CrMoAlA alloy steel subjected to multi-stage gas/ion nitriding, achieving a surface hardness of HV 950–1050 and a hardened case depth of 0.4–0.6 mm. The liner is made from high-phosphorus wear-resistant ductile iron.
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⚖️ Trademark Disclaimer: IMO® is a registered trademark of IMO AB / CIRCOR International. Orbi Pump is an independent manufacturer of precision three-screw pumps and replacement parts. Brand names and model designations are used for cross-reference and identification purposes only.