A long-term success story
Almost 10 years ago, a refinery in Europe upgraded their Reformer Feed pumps to DuPont™ Vespel® CR-6100. Last month, we checked in to see how the pumps are running.
The Reformer Feed pumps are 10-stage, axially-split, between-bearings pumps (API Type BB3), running at 2950 RPM. The product is naphtha at 185 C (365 F). There is one pump in the service, plus a spare rotor in the warehouse.
Problems in the Past
Marginal suction conditions make this a very tough service. The pumps take suction from a stabilizer tower bottom with NPSHA of only about 3 meters (10 feet). Due to the low NPSHA, it is very easy for the fluid to vaporize in the pump during start-up, causing the pump to run dry. This was formerly the normal reason for repairs due to the metal wear parts galling and seizing. If the metal parts did not seize, the throttle bushing would wear out, causing seal failures at the non-drive end.
Vespel® CR-6100 Survives
In 2009, the first pump in the service was upgraded with Vespel® CR-6100 case wear rings, center bushing, and throttle bushing. By eliminating the metal-to-metal contact points in the pump, the risk of pump seizure was essentially eliminated. Once the original pump upgrade proved successful, the spare rotor was also upgraded, but it has never been installed. The original pump upgraded is still running today. The refinery engineer commented:
We know for sure the product has vaporized in the pump at least 3 times since the upgrade, with seal failures as the only damages. We haven’t exchanged the rotor yet, although we have the spare rotor upgraded in 2010 in the warehouse. So far, no one expects the rotor to be exchanged.
As an added bonus, the site notes that they achieved a significant efficiency increase with the upgrade, which allowed an increase in unit throughput of 10%.
Vespel CR-6100 Conclusion
Where the refinery suffered with multiple failures of metal parts in the past, the Reformer Feed pump has now been running nearly 10 years with Vespel® CR-6100. The upgrade has paid for itself many times over with better reliability, efficiency, and ease of operation.
If you have a service causing you headaches, or if you are looking to increase throughput on one of your feed pumps, contact Boulden today. We have Vespel® CR-6100 in stock in a wide range of sizes in the USA, Europe, and Singapore and we can assist with any application or design questions you have. If you know what you need, just request a quote. Until next time, be safe.
Moselle river between Luxembourg and Germany