Technical Data
Engineering & Performance Data
Performance and materials data for NAPCO rotary gear pumps — verified through in-house testing for durability and efficiency.
The following performance data was tested with water (specific gravity 1.0) at ambient conditions. Higher viscosity liquids may require lower pump RPM to achieve the desired GPM and discharge pressure. For other fluids and viscosities, contact NAPCO for review.
2″ Pump Performance
Performance data for the PA200C ductile iron pump and PA200S stainless steel pump.
| Pump RPM | Discharge Pressure (psi) | Flow (GPM) | Brake HP |
|---|---|---|---|
| 190 | 10 | 69 | .65 |
| 190 | 30 | 65 | 1.8 |
| 190 | 50 | 64 | 3.2 |
| 190 | 70 | 62 | 4.0 |
| 190 | 100 | 60 | 5.7 |
3″ Pump Performance
Performance data for the PA300C ductile iron pump and PA300S stainless steel pump.
| Pump RPM | Discharge Pressure (psi) | Flow (GPM) | Brake HP |
|---|---|---|---|
| 280 | 10 | 158 | 1.5 |
| 280 | 30 | 147 | 4.2 |
| 280 | 50 | 145 | 6.9 |
| 280 | 70 | 142 | 9.4 |
| 280 | 100 | 140 | 13.4 |
Pump Materials & Composition
NAPCO rotary gear pumps are available in stainless steel or as a ductile iron gear pump for non-corrosive duty, and come standard with high-temperature nitrile rubber gears rated up to 240°F. For higher temperatures or corrosive fluids, alternate gear materials and elastomers such as EPDM, urethane, or Viton are available.
| Material | Shaft | Gears | Housing | Gasket | High Pressure Seal | Low Pressure Seal | Bearings |
|---|---|---|---|---|---|---|---|
| Ductile Iron | Ductile Iron | Nitrile Rubber | Ductile Iron | Asbestos-Free Paper | Viton | Viton | Roller |
| Stainless Steel | Stainless | Nitrile Rubber | Stainless | Asbestos-Free Paper | Viton | Viton | Roller |
Pump Dimensional Data
Dimensions are carried on the drawings themselves rather than in a table. These are traced from the NAPCO factory sheets NAP200 and NAP300 — one drawing set per port size, shared by the stainless and ductile iron versions of that size. Click any view to enlarge.
3″ Pumps — PA300S and PA300C
Drive shaft may be fitted in either position.
Traced from NAPCO factory drawing · Rev. 07/20262″ Pumps — PA200S and PA200C
Drive shaft may be fitted in either position.
Traced from NAPCO factory drawing · Rev. 07/2026Related Resources
- Rotary Gear Pump Working Principle — Understand the technical mechanics and advantages of rotary gear pump design.
- Positive Displacement Pump Comparison — Gear vs. vane vs. piston pump engineering analysis.
- How to Size a Rotary Gear Pump — Calculate the right pump for your flow rate, pressure, and viscosity.
- Stainless Steel vs. Ductile Iron Pumps — Material selection guide for different fluid environments.
- Nitrile vs. Viton Gears — Elastomer selection based on temperature and chemical compatibility.
- Pump Sizing Calculator — Get instant pump recommendations based on your application parameters.
- View All Products — Browse rotary gear pumps and repair kits.
Need Application-Specific Performance Data?
Contact NAPCO engineering with your fluid type, viscosity, and operating conditions for customized performance guidance.