Description:

Light hydrocarbon services introduce a specific set of design and application challenges that require careful consideration when selecting and designing multistage centrifugal pumps. 
 
Low fluid density, low lubricity, high volatility, and elevated vapour pressure all significantly influence pump behaviour, rotordynamic stability, thrust balance, and sealing performance, particularly in higher pressure applications.
 
This presentation will outline the key design features and technical considerations that govern the successful selection and design of BB3 and BB5 multistage pumps for light hydrocarbon service, highlighting common pitfalls encountered in practice. The talk with cover the practical limits of BB3 versus BB5 selection, focusing on pressure containment, casing joint design, and leakage risk, discussing where API and industry experience differ. Rotor design features are then addressed, including wear ring material selection and clearance limits, and their influence on internal recirculation, rotor stability, and uptime. Approaches to axial thrust management are reviewed, with emphasis on behaviour during transients and the implications for thrust bearing loading.
 
Testing and validation aspects are examined, including hydrotesting and the limitations of factory performance testing on water and the potential for resonance or rotordynamic issues to remain undetected when reduced-speed testing is applied. The presentation also considers resonance risk and rotordynamic challenges associated with long, flexible multistage rotors operating in low-density fluids.
 
We will then cover post-test preservation, and shipping and storage practices and finally key commissioning stages, recognising their role in machine uptime.
 
Finally we will recap the key considerations to ensure any BB3 or BB5 is correctly specified and designed for any low SG service.

Presenter:

Samuel Eccles

Product & Commercial Director, Trillium Flow Technologies

Samuel Eccles is Product & Commercial Director at Trillium Flow Technologies, with almost 20 years’ experience in the pump and rotating-equipment industry. He holds a BEng in Engineering and an MBA.
 
He has worked extensively with API 610 centrifugal pumps, covering selection, design, testing and manufacturing across oil & gas, power, and water markets.