Seepex® Replacement Rotors
Replacement rotors for supported Seepex® BN, MD, BT and CS progressive cavity pumps, selected by complete model, pumping-element geometry, dimensions, material and service conditions.
ACCA evaluates the installed pump and rotor construction using model information, measurements, photographs, drawings or a physical sample. The mating stator and operating history should also be reviewed before replacement.
Replacement Rotors for Seepex® Pumps
The rotor is the metallic helical component that turns eccentrically inside the stator. Its geometry and controlled interference with the stator create sealed cavities that move product from suction to discharge.
Rotor selection requires more than the pump-family name. The complete model, pumping-element geometry, number of stages, overall and connection dimensions, base material, surface treatment and service conditions must be confirmed.
Information Needed to Identify a Seepex® Rotor
Complete Pump Model
Provide every letter, number and suffix shown on the nameplate or equipment records.
Overall Dimensions
Include total length, pumping-element length, major and minor diameters and available eccentric-geometry measurements.
Connection Details
Photograph and measure threads, pins, keyways, shoulders, drive connections and end geometry.
Material and Surface
Provide known metal and coating information plus photographs showing the present surface condition.
Process Conditions
Identify the fluid, concentration, temperature, solids, abrasion, corrosion, pressure and speed.
Drawing or Sample
A dimensional drawing or physical sample may be required for modified, unusual and legacy constructions.
Seepex® Pump Families Supported
BN Series
Rotors for supported standard block-pump models across established BN geometries and stage configurations.
MD Series
Metering rotors reviewed for complete model, small-flow geometry, stage configuration and controlled dosing duty.
BT Series
Rotors for supported hopper and feed-pump arrangements handling viscous and solids-bearing products.
CS Series
Rotors for supported food and hygienic configurations, subject to confirmation of material, finish and cleaning requirements.
Rotor Material and Surface Selection
Rotor material and surface treatment should be selected around the complete process environment and the condition of the mating stator. Corrosion, abrasion and dimensional wear can all change the pumping fit.
| Construction Direction | Typical Selection Considerations | Confirm Before Selection |
|---|---|---|
| Tool Steel | Industrial duties requiring strength and wear resistance | Fluid chemistry, corrosion exposure, solids and surface treatment |
| 316 Stainless Steel | Selected corrosive, food and process applications | Exact chemical environment, finish, cleaning requirements and abrasion |
| Hard Surface Treatment | Added resistance to abrasive wear and surface damage | Base metal, coating compatibility, required dimensions and process chemistry |
| Special Materials | Difficult chemical, corrosion, temperature or product-contact requirements | Complete application, material specification and any compliance requirements |
Common Rotor Wear and Failure Indicators
Abrasive Wear
Signs: polished flats, reduced rotor dimensions, scoring and loss of pressure performance. Review solids, speed and stator condition.
Corrosion and Pitting
Signs: surface pits, roughness or localized metal loss. Review the complete fluid chemistry, concentration and temperature.
Coating Loss
Signs: flaking, breakthrough, exposed base metal or uneven surface finish. Determine the cause before installing a new stator.
Scoring and Galling
Signs: longitudinal marks, material transfer or severe friction damage. Check dry running, foreign material and assembly conditions.
Connection Wear
Signs: loose pins, worn threads, damaged keyways or distorted shoulders. Inspect the mating drive and joint components.
Slip and Capacity Loss
Signs: declining output as discharge pressure rises. Measure and inspect the rotor and stator together.
Why the Stator Should Be Checked Too
The rotor and stator operate as a pumping pair. A worn, swollen, hardened or heat-damaged stator can make a serviceable rotor appear ineffective, while an undersized or damaged rotor can shorten the life of a new stator.
| Inspection Point | What to Check | Why It Matters |
|---|---|---|
| Rotor profile | Dimensions, wear pattern, straightness and surface condition | Controls cavity sealing and rotor-to-stator interference |
| Stator bore | Abrasion, swelling, hardening, cracking and heat damage | Identifies whether leakage or high torque originates in the stator |
| Drive connection | Threads, pins, keyways, shoulders and joint fit | Prevents torque-transmission and alignment problems |
| Operating history | Dry running, pressure events, speed and material changes | Helps prevent a repeated failure after replacement |
How to Request a Replacement Rotor
Send the complete pump designation exactly as shown on the nameplate or records.
Include full-length views, both ends, connection details, markings and damaged areas.
Provide overall length, pumping length, diameters and all available connection measurements.
Provide known base metal, surface treatment, finish and product-contact requirements.
Include fluid, temperature, solids, pressure, speed, corrosion and abrasion conditions.
Frequently Asked Questions
How do I identify a replacement Seepex® rotor?
Provide the complete pump model, rotor photographs, dimensions, connection details, material information and process conditions. A drawing or sample may be needed.
Can ACCA evaluate a worn rotor without an identification number?
Yes. Start with the complete pump model and provide accurate dimensions, photographs, an existing drawing or a physical sample.
Which dimensions are most important?
Useful measurements include overall length, pumping-element length, major and minor diameters and complete end-connection geometry.
Should a worn rotor be recoated or replaced?
The decision depends on dimensional wear, base-metal condition, connection integrity, existing coating and the required finished geometry. ACCA can review the available information.
Should the stator be replaced with the rotor?
Not automatically, but both components should be inspected together because their dimensional relationship controls capacity and pressure performance.
Can ACCA support food or hygienic rotor requirements?
ACCA can evaluate supported configurations when the required material, surface finish, cleaning conditions and any applicable compliance criteria are clearly stated.
Return to the Seepex® Pump Parts hub to browse BN, MD, BT and CS family information.
Seepex® Replacement Stators →
Seepex® Drive and Joint Parts →
Seepex® Mechanical Seals and Packing →
View All Seepex® Pump Parts →
Request a Seepex® Replacement Rotor
Send the complete model, rotor photographs, dimensions and service details. ACCA will review the information required to confirm a supported replacement.
Complete pump model
Rotor photographs
Overall and connection dimensions
Known material and coating
Drawing or sample, when available
Fluid and concentration
Temperature and solids
Differential pressure and speed
Corrosion and abrasion
Prior wear or failure pattern
Trademark Disclaimer: Seepex® is a registered trademark of its respective owner. References to Seepex® are used solely to identify compatible equipment. ACCA Pumps is an independent aftermarket manufacturer and is not affiliated with or endorsed by the trademark owner. Read the full disclaimer.