Pentair 1/2" #2-331 Upper and Lower Bulkhead O-ring

The Pentair 1/2" #2-331 Upper and Lower Bulkhead O-ring (part number 192115Z) is a precision-engineered sealing component used across various Pentair pool and spa filtration systems, including Clean & Clear cartridge filters, FNS Plus, and Quad D.E. filters. Molded from premium, heavy-duty synthetic rubber (EPDM/Nitrile) compounds, this circular gasket is specifically built to withstand constant compression, extreme water temperature fluctuations, and continuous exposure to harsh pool chemicals like chlorine and bromine. Its critical structural function is to create an absolute watertight seal between the filter tank wall and the upper or lower internal bulkhead connections, effectively preventing dangerous external leaks and maintaining the hydraulic integrity of the filtration system under high pressure. Because it is a small, specialized rubber ring, this individual component is exceptionally lightweight, carrying a total product and shipping weight of approximately 0.02 pounds (less than half an ounce), making it a crucial yet effortless replacement part for routine filter maintenance.