Pump column spools shall be flanged with proper alignment.
      The shaft will be precision forged, machined and adjusted, and will be of suitable size to safely and continuously withstand all the stresses resulting from start-up conditions and continuous operation.

The shaft shall be provided with replaceable shaft sleeves. The sleeves shall be keyed to the shaft. Shaft sections shall be fastened with couplings designed and locked so that they will not become loose due to reverse rotation of the pump unit.