Lassen High Vacuum, Inc. follows industry-standard best practices and exacting standards for every cryogenic pump and compressor rebuild.  We back our rebuilds with a one (1) year warranty.

  • Standard Lead-Time:  Ten (10) Business Days.
    • Expedited Lead-Time and On-Site Rebuild Services Available for Additional Cost.

Our rebuilding process is as follows:

  1. Receiving and Evaluation 
    • Pump, Compressor and/or any associated components are photographed.
    • Any damaged or missing components are noted.
      • Note:  Customer is required to provide details on any contamination that may be present in the pump and/or any associated components.
    • All items received are logged into the Lassen tracking system for trace-ability throughout the rebuild process.
    • Customer is contacted to advise of any damage or missing components that could add to the standard rebuild cost.
  2. Disassembly 
    • All rebuild-able items are dis-assembled to the major component level.
    • Components are inspected and all critical tolerances are measured.
    • Second-Stage 15k Charcoal Condensing Array is discarded.
    • Failure analysis report generated.
  3. Reconditioning
    • All items are ultrasonically cleaned.
    • Decontamination procedures are performed as needed.
    • Radiation Pot is media blasted and repainted with low emissivity paint.
    • Frontal (first-stage) array is re-plated with electroless nickel.
    • New 15 Kelvin charcoal condensing array is installed.
    • On-board roughing valve assembly is refreshed as needed.
    • Other on-board modules are refreshed as needed.
  4. Reassembly
    • All items re-assembled per original manufacturers specifications.
  5. Test
    • Cool-down test (time vs. temperature) is performed.  Performance results verified.
    • Motor vibration test.
    • Vacuum vessel leak checked with helium leak detector.
    • Hour meter is reset to zero (0) for on-board pumps.
  6. Packaging and Shipment
    1. Lassen rebuild identification tag applied to rebuilt item(s).
    2. Item(s) are bagged and prepared for shipment.

Rebuild Process Summary

Vacuum SideHelium Circuit
Disassemble and clean parts to be reused.Replace all elastomers and all components subject to wear.
Replace 15K condensing array with new assembly.Inspect 2nd stage displacer regenerator material and repack or replace as necessary.
Replace 80K condensing array and 80K radiation shield if needed.Inspect all parts for damage.
Inspect and test silicon diode. Diode is repaired or replaced if required.Set intake/exhaust valve timing and test inlet valve for perfect seal.
Reassemble in clean room conditions using new indium gasket set.Test motor for appropriate torque and re-magnetize motor.
Upgrade to new style relief valve and install "standpipe" filter.Leak check using helium sniffing leak detector.
Leak check with helium mass spectrometer leak detector.Perform cool-down test and verify performance.