Ten years ago, Greene, Tweed & Co. successfully introduced a carbon-fiber-reinforced polyetheretherketon (PEEK) containment shell under the trade name Xycomp®, to serve the API 685 seal-less pump market (Weibel, Bieler, Magnetic-coupled pumps: the containment shell. EEMODS’09, Paper #46, 6 May 2009). Today, we introduce a new material called Xycomp® DLF (i.e., Discontinuous Long Fibers) for lower pressure rated shells, targeting the ANSI/ASME market. This new material offers the same high-service temperature of 180 °C (350 °F) at a significantly lower price. It was originally developed to serve the Aerospace market, where it sees a great success and market traction. Creating pump-shells from Xycomp® DLF was an obvious match, as it allows eliminating the eddy currents generated by current metallic shells, and therefore offers significantly higher safety in case of an upset condition such as fluid starvation and subsequent dry running. Compared to other non-metallic shells, such as those made from ceramics, Xycomp® is non-fragile, insensitive to thermal shock, and does not build up electrostatic charges. Its failure mode is well understood and highly predictable as required for any Aerospace application.
With current legislation requiring zero emissions when pumping fluids are identified as hazardous (e.g., carcinogenic, explosive, toxic), magnetically coupled pumps offer a reliable alternative to the expensive and maintenance-intensive, double mechanical sealed pumps. However, if a magnetically driven pump is lined with a metallic containment shell, the required power to drive the pump is increased due to the eddy current losses. To overcome the eddy current losses (15–25% for large pumps), additional power is needed, and it is not always available in existing buildings, leading to higher service cost. With Xycomp® DLF shells, the same power will be required to drive the impeller as a mechanically driven pump.
This chapter presents the results of a large number of internal and field tests performed on many different Xycomp® shell sizes and pressure ratings, demonstrating the high reliability and advantages over other industry standard shells. Results include creep tests up to 204 °C (399 °F) for 10,000 h, statistical shell burst pressures from −196 °C to 200 °C (−320 °F to 392 °F), fatigue testing up to 36,000 cycles, dry running up to 12 min, sand erosion wear, pumped fluid temperature increase as a function of flow rate, thermal shock, fire burn through tests, thermal expansion, and impact resistance.
