Liquids pumped near their vapor pressure must be cooled for successful sealing. Hot water, for example, has low lubricity and causes high seal face wear. Flashing can open the seal faces, causing leakage and seal face damage.
API Plan 23 (ANSI Plan 7323) is the most reliable and economical way to cool a seal. The sealed liquid is circulated from the seal chamber (not the pump discharge) through a cooler and back to the seal. Since only the liquid around the seal is cooled, the heat load on the cooler is minimized and process energy is conserved. Cooler fouling is reduced, extending cooler life.
The AST 7023 seal is the off-the-shelf solution for hot liquid sealing. Its built-in pumping ring fits in enlarged bore seal chambers on popular ANSI pumps.