Reactor charging pumps

1. Introduction In refinery and petrochemical applications, selecting the right pump type is critical for ensuring reliability, efficiency, and long-term operation. Among the various pump types defined in API 610, OH2 and BB2 pumps are two of the most commonly used configurations. Although both are centrifugal pumps designed for demanding services, their structural differences make them suitable for different operating conditions. This article explains the key differences between OH2 and BB2 pumps and provides practical guidance for selection. 2. What is an OH2 Pump? An OH2 pump is a single-stage, overhung, horizontal centrifugal pump with a centerline-mounted casing. Key characteristics: l Overhung impeller design (impeller mounted at shaft end) l Single bearing housing l Flexible coupling to driver l Centerline support for thermal stability Typical applications: l General refinery services l Medium pressure and temperature fluids l Clean or slightly contaminated liquids 3. What is a BB2 Pump? A BB2 pump is a single-stage, between-bearings centrifugal pump, typically with a radially split casing. Key characteristics: Impeller located between two bearings Double-bearing support for higher shaft rigidity Better load distribution Designed for higher pressure services Typical applications: High-pressure hydrocarbon services Critical process units Applications requiring high reliability 4. Key Differences Between OH2 and BB2 Pumps 5. Application Comparison When to use OH2 pumps: l General process services l Moderate pressure and temperature l Cost-sensitive projects l Easier maintenance required When to use BB2 pumps: l High-pressure systems l Critical units (e.g., hydrocracking, boiler feed) l Continuous operation with minimal downtime l Applications requiring higher mechanical stability   6. Selection Guide   Choosing between OH2 and BB2 pumps depends on several key parameters: 1. Operating Pressure Medium pressure → OH2 High pressure → BB2 2. Reliability Requirement Standard duty → OH2 Critical service → BB2 3. Fluid Conditions Clean / low viscosity → both suitable Severe conditions → BB2 preferred 4. Maintenance Strategy Frequent maintenance acceptable → OH2 Long continuous operation required → BB2 5. Budget Consideration Lower CAPEX → OH2 Higher initial cost but longer lifecycle → BB2   7. Practical Example In refinery applications: OH2 pumps are often used in: Transfer services Utility systems Light hydrocarbon handling BB2 pumps are typically selected for: High-pressure feed systems Reactor charging Critical process circulation   8. Conclusion Both OH2 and BB2 pumps play essential roles in petrochemical and refinery industries. The choice between them should not be based solely on cost, but on a comprehensive evaluation of operating conditions, reliability requirements, and lifecycle considerations. In general: OH2 = flexibility + lower cost BB2 = stability + high reliability   9. Need Technical Support? If you are selecting pumps for refinery or petrochemical applications and are unsure whether OH2 or BB2 is the better choice, feel free to contact us. We can provide: Pump selection support API 610 compliant solutions Customized designs for critical applications