HYDRAULIC RERATE INCREASES PRODUCTIVITY AND REDUCING MTBO AT OIL REFINERY

CHALLENGE

Our customer wanted to modify the hydraulic performance of two OH2 pumps (one running, one spare) for a gas oil pumping process in a refinery, according to new process conditions. The pumps already suffered intermittent cavitation phenomenon due to low available NPSH and it modelling had shown that the required changes in process conditions would lead to permanent cavitation problems.

The customer asked Celeros Flow Technology company ClydeUnion Pumps to perform an upgrade to meet the new rated point and solve the cavitation issue, with a 30 week lead time to carry out the pumps disassembly and modifications during a process shutdown.

SOLUTION

Calculations performed using the new process conditions identified that the OH2 pumps required an increase in impeller diameter to meet the new required flow for an unchanged head, as well as the addition of a specially designed inducer to avoid cavitation. These modifications were possible using spare parts available from the customer: but follow feasibility studies, the customer decided to order two new bare shaft pumps integrating the upgrades rather than modify the existing pumps.

OUTCOMES

The modified pumps are operating as planned, and capacity of the oil gas process has increased in line with customer expectations. The reduction in cavitation has led to an increase in MTBO, reducing maintenance frequency and cost.