Abstract: A pump having a heat exchanger including a rotating baffle sleeve secured to the pump shaft. A seal baffle on the rotating baffle sleeve extends over the pump seal assembly cartridge. A cooling cylinder containing circulating component cooling water is suspended within the rotating baffle sleeve and defines a flow passageway therein for cooling heated product water, before the product water contacts the shaft seal. A seal injector distributor ring uniformly distributes seal injection water to the seal. A thermal shield in the heat exchanger reduces thermal stresses in the heat exchanger. A slotted keyway spacer ring facilitates replacement and alignment of a hydrostatic bearing.