CENTRIFUGAL PUMPS- COMPARISON OF API AND ANSI PUMP STANDARDS
Comparison of API and ANSI Pump Standards
| API-610 | ANSI B73.1 | |
| Pressure Rating | – All pressures and temperatures normally encountered | – ANSI Class 150 and temperatures up to 500F |
| Pump Casings | – ASME Section VIII, Div. 1 – Carbon or alloy steel required in flammable or toxis service |
– Ductile iron, carbon steel or alloy steel required for flammable or toxic service |
| Impellers |
– Single piece castings – Secured to shaft with a key |
– May be keyed or threaded to shaft |
| Wear Rings | – Minimum hardness of 400 BHN or hardness difference of 50 | – No requirements |
| Mechanical Seals | – Required | – No requirements |
| Shaft Critical Speed | – Lateral critical speed greater than 120% of maximum pump speed | – No requirements |
| Bearings |
– Three-year life for ball bearings – Hydrodynamic and thrust bearings where: bearing diameter (mm) x pump rpm >300,000 or, pump rated HP x pump rpm > 2.7 x 10^6 |
– Two-year life for ball bearings |
| Baseplates |
– Drip lip or drain pan required – Adequate to limit shaft dispacement at coupling to in |
– No requirements |
| Testing |
– Hydrostatic test to 1.5 times allowable casing pressure for 30 minutes – Performance test required |
– Hydrostatic test to 1.5 times allowable casing pressure for 10 minutes |