Product Description
Major Repair Kit for Pfeiffer DUO 125 (Index B) / DUO 125 – OEM-Equivalent
Vacuum Pump Supply OEM-Equivalent Replacement for Pfeiffer Vacuum Pumps
Part Number: PMK025
Vacuum Pump Supply's OEM-equivalent major repair kit for DUO 125 (Index B), DUO 125 is designed to provide reliable fit and performance for vacuum pump repair and maintenance. This product offers a cost-effective alternative to OEM replacement parts while supporting dependable pump operation.
Compatible Pump Models
- DUO 125 (Index B)
- DUO 125
Product Features
- Vanes and wear components
- Shaft seals, O-rings and gaskets
- Springs and valve components
- Coupling or drive components where applicable
- Components commonly replaced during major overhaul
When Should This Be Replaced?
Replace or install this component during complete rebuild, reduced vacuum performance, worn vanes, oil leaks, noisy operation, or scheduled overhaul.
Complete Bill of Materials
The following components are included in this kit.
| Part Number | Description | Qty |
|---|---|---|
| 580044 | Piston,Hydraulic,Viton | 1 |
| 330096 | Ball,Steel,8 mm diameter, Mirror Finish | 1 |
| 320522 | O-Ring,Viton, 88x5 mm | 1 |
| 320521 | O-Ring,Viton, 75.56x5.33 mm | 3 |
| 320529 | O-Ring,Viton,410 X 3 mm | 1 |
| 23714036 | O-Ring,Viton,150 X 3 MM | 1 |
| 320336 | O-Ring,Viton,94 x 2.5 | 1 |
| PL23970419 | O-Ring,Viton,125 X 5 MM | 1 |
| 220005 | Key,Round ends | 1 |
| 220004 | Key,Feather,5 x 5 x 10,RND ENDS | 1 |
| 380048 | Plate,Spring,Non Return Valve | 2 |
| 580052 | Valve,Compression,UNO/DUO 120-250 | 1 |
| 390028 | Seat,Valve | 2 |
| 380047 | Plate,Valve,Aluminum, with O-Ring | 1 |
| 700074 | Filter,Pleated,Rubber Housing,DUO125 | 1 |
| PL20011245 | Finger,Exhaust | 2 |
| 490070 | Spring,DUO 125 | 1 |
| 580054 | Valve,Stamp | 2 |
| 490071 | Spring,DUO 125 | 1 |
| 250030 | Sleeve,Steel,DUO 120,125 | 1 |
| 700073 | Filter,Star-shaped Screen | 1 |
| 490069 | Spring,Vane | 8 |
| 440050 | Spacer,DUO 120A | 1 |
| 560014 | Sieve,Cylinder,DUO 120A | 1 |
| 230093 | Vane,GX,2nd Stg,DUO 120A/125A | 2 |
| 520035 | Ring,Support,DUO 120A | 1 |
| 300167 | Gasket,Sight Glass | 2 |
| 23970139 | O-Ring,Viton,100 X 5 MM | 1 |
| 320538 | O-Ring,Viton,85X5mm | 1 |
| PL23970129 | O-Ring,Viton,65 X 5 MM | 2 |
| 48652700 | O-Ring,Viton,66X2mm | 1 |
| 320524 | O-Ring,Viton, 32 x 2.5 mm | 2 |
| 2124025 | O-Ring,Viton,28 X 5 MM | 1 |
| 4070420 | O-Ring,Viton,24 X 2.5MM | 4 |
| 4070333 | O-Ring,VIT.19X2.5MM,UNO/DUO1.5 | 1 |
| 320177 | O-Ring,Viton,18x2.0mm | 1 |
| 4070166 | O-Ring,Viton.10 X 2.5MM | 1 |
| PL23970149 | O-Ring,Viton,8 X 2 MM | 1 |
| 4070088 | O-Ring,Viton,6 x 2.2 mm | 1 |
| 310149 | Seal,Oil,DUO 120A | 2 |
| 512107041 | Coupling,Insert,Rotex 42 | 1 |
| 330094 | Bearing,Needle | 4 |
| 230092 | Vane,GX,1st Stg,DUO 120A/125A | 2 |
| 490074 | Spring,40 mm Long,DUO 125 | 2 |
| 390024 | Buffer,Valve,Safety | 1 |
| 490073 | Spring,DUO 125 | 2 |
| 500023 | Sight Glass,UNO/DUO 35/65 | 1 |
Recommended Products
Complete the Service
Fresh vacuum pump oil and clean filtration are recommended whenever servicing or rebuilding an oil-sealed rotary vane vacuum pump.
Why Buy from Vacuum Pump Supply?
- Vacuum pump specialists since 2006
- OEM-equivalent replacement parts built for value and reliability
- Fast shipping on stocked products
- Technical support from vacuum pump specialists
- Trusted by manufacturers, laboratories, universities, service companies, and maintenance teams
Helpful Resources
- Vacuum Pump Oil Cross Reference Chart
- Vacuum Pump Schematics, Manuals & Repair Resources
- Rotary Vane Vacuum Pump Repair Kits & Parts
- Pfeiffer Vacuum Pump Parts & Kits
Frequently Asked Questions
Is this a genuine OEM Pfeiffer product?
No. This is a Vacuum Pump Supply OEM-equivalent replacement product designed for use with compatible Pfeiffer vacuum pumps.
What pump is this product for?
This product is listed for DUO 125 (Index B), DUO 125.
What is the part number?
The part number is PMK025.
Should I change the oil during service?
Yes. Fresh vacuum pump oil is recommended whenever a pump is serviced, resealed, or rebuilt.
