In some pump applications, the water pressure at the seal face may be less than atmospheric pressure outside the seal. Pumps used in that situation may have an external line piped from a high pressure point in the pump (near the discharge) to the seal face area to increase the pressure there and provide lubricating flow. Without that, the seal will leak backwards, with air passing through the seal into the pump.
Some pumps, especially those pumping dirty fluids with abrasive dirt or the like in them, have seal flush arrangements that pump clean water to the seal face since dirt in the fluid will wear out the seal. I haven't seen an externally supplied cooling setup but don't doubt that it exists. High temps are also hard on seals.
