Heat Exchanger, Ref SVCE (542,561,642,680)
   542    Use Regardless of Serial Number.
   561    Use From M/P1198140 to M/P1200489.
          Use Starting with M/P1203140.
          See 4250980 For Additional Serial Breaks
   642    Use Prior to Serial #2143499.  Starting
          With Serial #2143499, See 7016178.
   680    Use Prior to Serial #1810000.  Starting
          With Serial #1810000, See 4251300.