Casappa KP20 (KAPPA 20) High Pressure Cast Iron Gear Pump
Casappa KP20 (KAPPA 20) High Pressure Cast Iron Gear Pump – Detailed Technical Data
KP20 is a two-piece grey cast iron external gear pump. It allows through-shaft for multi-pump assembly. Side or rear port options; SAE / European standard flanges available. Units: cc/rev = cm³/r; bar; rpm. Continuous pressure = long-term allowable working pressure; Peak pressure = short-time shock pressure, NOT for continuous operation.
1. Pressure & Speed for each displacement
| Model | Displacement cc/rev | Continuous Pressure bar | Peak Pressure bar | Max Speed rpm | Min Continuous Speed rpm |
|---|---|---|---|---|---|
| KP20.4 | 4.95 | 285 | 330 | 4000 | 350 |
| KP20.6.3 | 6.61 | 285 | 330 | 4000 | 300 |
| KP20.8 | 8.26 | 285 | 330 | 3500 | 350 |
| KP20.11.2 | 11.23 | 275 | 320 | 3500 | 350 |
| KP20.14 | 14.53 | 265 | 320 | 3500 | 350 |
| KP20.16 | 16.85 | 260 | 320 | 3000 | 300 |
| KP20.20 | 21.14 | 210 | 250 | 3000 | 300 |
| KP20.25 | 26.42 | 180 | 210 | 2500 | 300 |
| KP20.31.5 | 33.03 | 140 | 170 | 2000 | 300 |
Note: Larger displacements have lower rated continuous pressure. Large displacement versions are suitable for medium pressure & high flow, NOT continuous high-pressure service.
2. General Mechanical & Hydraulic Specifications
- Housing Material: Grey cast iron, two-piece construction
- Bearings: Pressure-compensated sliding thrust bearings for improved volumetric efficiency
- Rotation: Standard clockwise (viewed from drive end); counter-clockwise available on request, specify in order code
- Drive Shaft Options
- Parallel key shaft (common code 82E2)
- 1:8 taper shaft
- SAE splined shaft (optional)
- Mounting Flange: 4-hole European standard flange (D0 most common); SAE flange optional
- Port Arrangement: Side outlet (L series) or rear outlet (R series); flange type ports
- Multi-pump capability: Through-shaft design. KP20 can be cascaded with KP20 / KP30 / KP40 to form multi-section pumps.
Fluid, Temperature & Contamination
- Recommended hydraulic fluid: Mineral hydraulic oil ISO VG32 / VG46
- Operating temperature: -20℃ ~ +80℃; short-time peak up to 90℃
- Recommended viscosity during operation: 15～100 mm²/s; max 500 mm²/s allowed for cold start
- Fluid cleanliness: ISO 4406 18/15 or better. Inlet filter ≥100μm recommended; pressure line filter 10μm
- Seals: NBR nitrile rubber (standard). FKM fluorocarbon seals optional for high temperature / fire-resistant fluids (special order)
Typical Efficiency Values (at 150 bar, 2000 rpm, VG46 @50℃)
- Volumetric efficiency: ≥92% for small displacements 4
16cc; 8891% for 20cc and above - Overall efficiency: 84%~88% (depends on displacement and operating pressure)
3. Outline Weight Reference (D0 flange, side ports, parallel key version)
| Model | Weight (kg) |
|---|---|
| KP20.4 ~ KP20.11.2 | approx. 4.3~4.7 kg |
| KP20.14 ~ KP20.16 | approx. 4.8~5.0 kg |
| KP20.20 ~ KP20.31.5 | approx. 5.1~5.6 kg |
Weight varies slightly with port and shaft configuration. Exact outline & mounting dimensions refer to original manufacturer drawings.
4. Model Code Explanation (Example: KP20.16D0-82E2-LEB/EA-N)
- KP: KAPPA gear pump
- 20: Group 20
- 16: Nominal displacement 16.85 cc/rev
- D0: Flange code (4-hole European flange)
- 82E2: Shaft code, parallel key shaft
- LEB/EA: Port code, side ports, inlet / outlet port size
- N: Rotation code: clockwise (viewed from drive end)
5. Important Selection Notes
- Peak pressure applies only for short-duration shock (<0.5 sec), cannot run continuously. Design system based on continuous pressure for sizing.
- Do NOT operate at maximum speed together with maximum continuous pressure simultaneously; derating required otherwise service life reduces drastically.
- Suction condition: Vacuum at inlet should not be worse than -0.05 bar to avoid cavitation. Suction piping should be short and large bore.
- Data extracted from Casappa official datasheet. Final selection and acceptance shall refer to original Casappa PDF datasheet; agent data for reference only.
