Vespel® - Model CR-6100 - Throttle Bushings
Throttle bushings and center-stage bushings are upgraded to Vespel® CR-6100 for similar reasons as the pump wear rings.
What to do When Applying Vespel CR-6100 to Pump Throttle Bushing:
- Use the existing metal center-bushing housing as a holder for a Vespel® CR-6100 insert.
- Depending on the part geometry and operating temperature, the throttle bushing can be made from either solid Vespel® CR-6100, or the existing metal part can be used as a holder for a Vespel® CR-6100 insert.
- If you have upgraded the wear rings to Vespel® CR-6100, reduce the clearance of the throttle and center bushing to be 0.002” (0.05 mm) less than the wear ring clearance. Otherwise, keep the original design clearance.
- Make sure the pump overhaul results in good rotor concentricity. (The rotor should turn freely after assembly. Slight rubbing at the wear rings from shaft sag is normal, but any hard rubs should be corrected before putting the pump into service.)
- Use PERF-Seal™ design for high differential pressures and temperatures
- Eliminating the metal-to-metal contact points nearly eliminates the risk of pump seizure
- The throttle and center bushing will not seize or gall during slow roll or alignment
- The pump will have a better tolerance of run-dry events and other process upsets, with a chance of surviving extended off-design conditions
- Higher efficiency due to lower leakage losses across the throttle bushings