Moyno® 331 Pump Parts
OEM-compatible replacement components and part-number cross-references for supported Moyno® 331 progressive cavity pumps.
This page organizes 331 family housings, rotors, stators, flexible joints, drive shafts, bearings, mechanical seals and service components using the OEM 500 Series parts structure.
331 Engineering Overview
The 331 belongs to the 500 Series 300-model family and uses a flexible joint between the drive shaft and rotor. OEM service documentation lists cast-iron and 316 stainless mechanical-seal configurations as well as NBR, EPDM and FPM elastomer options. ACCA excludes nylon pump configurations from this catalog.
Flexible-Joint Drive Train
The shaft, flexible joint and rotor transmit torque while allowing the eccentric rotor motion required by the progressive cavity pumping element.
Material Identification
Confirm the complete pump model before ordering. Housing, shaft, joint, rotor and sealing materials vary between cast-iron and 316 stainless configurations.
Rotor and Stator Selection
The OEM parts list identifies 331-specific rotor and stator numbers separately from the common mechanical service parts.
331 Engineering Data
| Engineering Data | Specification |
|---|---|
| Pump Family | Moyno® 500 Series |
| Base Model | 331 |
| Joint Design | Flexible joint |
| Standard Mechanical-Seal Construction | 33101 cast iron / 416 SS and 33104 316 SS / 316 SS |
| Stator Elastomers Listed | NBR, EPDM, FPM |
| Rotor Materials Listed | 416 stainless steel and 316 stainless steel |
| Maximum Speed in OEM Service Manual | 1750 RPM |
| Nylon Configurations | Excluded from ACCA 500 Series catalog |
Replacement Parts Available
The 331 page follows the same ACCA engineering-catalog structure used on the L-Frame pages.
Rotor
416 SS and 316 SS rotor references for the 331 family.
Stator
NBR, EPDM and FPM stator references for the 331 family.
Flexible Joint
Carbon-steel and stainless joint options according to elastomer and construction.
Drive Shaft
Drive-shaft references for cast-iron and stainless pump configurations.
Bearings
Sealed bearings, spacer and retaining components.
Mechanical Seal
Standard and conversion seal references for NBR, EPDM and FPM.
Repair Kits
OEM elastomer repair / conversion kit cross-references.
Service Hardware
Snap rings, slinger ring, plugs, screws, stator ring and lock washers.
Moyno 331 Replacement Parts Reference
ACCA part numbers follow the catalog convention of adding the A- prefix to the OEM part number. Nylon-specific components are not included.
| Ref. | Component Description | ACCA Part Number | OEM Part Number | Notes / Applicable Types |
|---|---|---|---|---|
| 1 | Pump Body – Cast Iron | A-330-1065-002 | 330-1065-002 | 33101 |
| 1 | Pump Body – 316 Stainless Steel | A-330-1910-002 | 330-1910-002 | 33104 |
| 2 | Suction Housing – Cast Iron | A-330-1064-002 | 330-1064-002 | 33101 |
| 2 | Suction Housing – 316 Stainless Steel | A-330-1911-002 | 330-1911-002 | 33104 |
| 21 | Standard Stator – NBR | A-340-3501-120 | 340-3501-120 | 331 family |
| 21 | Stator – EPDM | A-340-3501-320 | 340-3501-320 | 331 family |
| 21 | Stator – FPM | A-340-3501-520 | 340-3501-520 | 331 family |
| 22 | Rotor – 416 Stainless Steel | A-320-2729-000 | 320-2729-000 | 331 family |
| 22 | Rotor – 316 Stainless Steel | A-320-2933-000 | 320-2933-000 | 331 family |
| 24 | Joint – Carbon Steel / NBR | A-320-1511-000 | 320-1511-000 | NBR configuration |
| 24 | Joint – 316 Stainless Steel / NBR | A-320-3759-000 | 320-3759-000 | Optional 316 SS / NBR |
| 24 | Joint – 316 Stainless Steel / EPDM | A-320-6367-000 | 320-6367-000 | EPDM conversion / repair |
| 24 | Joint – 316 Stainless Steel / FPM | A-320-4670-000 | 320-4670-000 | FPM conversion / repair |
| 26 | Drive Shaft – 416 Stainless Steel | A-320-1499-000 | 320-1499-000 | 33101 |
| 26 | Drive Shaft – 316 Stainless Steel | A-320-2938-000 | 320-2938-000 | 33104 |
| 29 | Bearing (2 Required) | A-630-0502-031 | 630-0502-031 | 331 mechanical-seal configurations |
| 33 | Bearing Spacer | A-320-1900-000 | 320-1900-000 | 331 family |
| 66 | Snap Ring | A-320-1506-000 | 320-1506-000 | 331 mechanical-seal configurations |
| 69 | Mechanical Seal – NBR | A-320-2424-000 | 320-2424-000 | NBR configuration |
| 69 | Mechanical Seal – EPDM | A-320-6379-000 | 320-6379-000 | EPDM conversion / repair |
| 69 | Mechanical Seal – FPM | A-320-6501-000 | 320-6501-000 | FPM conversion / repair |
| 77 | Slinger Ring | A-320-6382-000 | 320-6382-000 | 331 mechanical-seal configurations |
| 100 | Pipe Plug (3 Required) | A-610-0120-021 | 610-0120-021 | 331 mechanical-seal configurations |
| 112 | Screws (8 Required) | A-619-1430-103 | 619-1430-103 | Cast-iron configuration |
| 112 | Screws (8 Required) | A-320-5968-000 | 320-5968-000 | 316 stainless configuration |
| 135 | Stator Ring | A-320-7812-000 | 320-7812-000 | 331 and 332 models |
| 215 | Lock Washer (8 Required) | A-320-6464-000 | 320-6464-000 | 331 mechanical-seal configurations |
| KIT | Elastomer Repair / Conversion Kit – NBR | A-311-9026-000 | 311-9026-000 | 331 models |
| KIT | Elastomer Repair / Conversion Kit – EPDM | A-311-9025-000 | 311-9025-000 | 331 models |
| KIT | Elastomer Repair / Conversion Kit – FPM | A-311-9054-000 | 311-9054-000 | 331 models |
| AR | Abrasion-Resistant Seal – NBR | A-3206460000 | 3206460000 | 331–344 models |
| AR | Abrasion-Resistant Seal – EPDM | A-3206502000 | 3206502000 | 331–344 models |
| AR | Abrasion-Resistant Seal – FPM | A-3206503000 | 3206503000 | 331–344 models |
331 Component Notes
Rotor
The OEM 331 rotor table lists 416 stainless steel part number 320-2729-000 and 316 stainless steel part number 320-2933-000.
Stator
The OEM stator table lists 340-3501-120 for NBR, 340-3501-320 for EPDM and 340-3501-520 for FPM.
Flexible Joint
NBR configurations include carbon-steel joint 320-1511-000, with 316 stainless/NBR joint 320-3759-000 also listed. EPDM and FPM conversion references use 316 stainless joints with the appropriate elastomer.
Drive Shaft
Part number 320-1499-000 is listed for the 33101 construction and 320-2938-000 for the 33104 stainless construction.
Bearings
The 331 family uses sealed ball bearings. The parts list identifies bearing 630-0502-031 with two required.
Mechanical Seal
The repair / conversion table lists NBR, EPDM and FPM seal assemblies to match the selected elastomer family.
Engineered Material Options
ACCA supplies compatible 331 components in application-appropriate metallic and elastomer selections. The source documentation lists NBR, EPDM and FPM stators; 416 SS and 316 SS rotors; carbon-steel/NBR and stainless flexible-joint options. ACCA can also provide special elastomer and material solutions for operating conditions requiring additional chemical, temperature or abrasion resistance. Nylon pump configurations are not included.
331 Repair and Conversion Kits
The OEM repair / conversion table groups the stator, joint and seal by elastomer family.
| Elastomer | ACCA Kit Number | OEM Kit Number |
|---|---|---|
| NBR | A-311-9026-000 | 311-9026-000 |
| EPDM | A-311-9025-000 | 311-9025-000 |
| FPM | A-311-9054-000 | 311-9054-000 |
Frequently Asked Questions
Which Moyno 331 configurations are covered?
This page covers the standard 331 family with cast-iron and 316 stainless mechanical-seal configurations and identifies the 331 family rotor, stator, flexible-joint, seal and service-part references. ACCA does not include nylon pump configurations in this catalog.
Which stator elastomers are listed for the 331?
The OEM service documentation lists NBR, EPDM and FPM stators for the 331 family.
Which flexible-joint options are listed for the 331?
The service documentation lists carbon-steel/NBR as well as 316 stainless joint options for NBR, EPDM and FPM configurations.
Which rotor materials are listed for the 331?
The 331 rotor table lists 416 stainless steel and 316 stainless steel rotor options.
How are ACCA part numbers created on this page?
The ACCA catalog number uses the OEM part number with an A- prefix so maintenance and purchasing teams can cross-reference the original number directly.
What information should I send ACCA for a 331 quotation?
Send the complete pump model, serial number, OEM part number when available, quantity, material or elastomer requirements, and clear photographs of the nameplate or existing component.
Why Choose ACCA 331 Replacement Parts?
OEM-Compatible Fit
Replacement components are selected for dimensional interchangeability with supported 331 configurations.
Material Support
Metallic and elastomer choices can be reviewed against the actual fluid, wear conditions and operating environment.
Engineering Support
ACCA can help identify replacement components from the model, serial number, OEM part number and existing part photographs.
Related 500 Series Models
Need Help Identifying Moyno 331 Parts?
Send the complete pump model, serial number and OEM part number when available.
Trademark Disclaimer: Moyno® is a registered trademark of its respective owner. References are used solely to identify compatible equipment and replacement applications. ACCA Pumps is an independent aftermarket manufacturer and is not affiliated with or endorsed by the trademark owner.
Complete 331 Replacement Pump
If the application requires a complete pump rather than individual components, review the Moyno 331 compatible replacement pump from ACCA Pumps.
Complete 331 Replacement Pump
If the application requires a complete pump rather than individual replacement parts, review the Moyno 331 compatible replacement pump from ACCA Pumps.