Berliss BSP-758 XP-I-I-1.521 Pump Shaft Seals

Berliss BSP-758 is a Type 21 standard, unbalanced mechanical shaft seal designed for 1-1/2 in pump shafts. The assembly pairs a carbon rotating face with a ceramic stationary seat and a ceramic mating ring, all housed in Buna‑N elastomer and supported by a stainless‑steel spring and retainer for durability. Key dimensions include a seal head outside diameter of 2.187 in, a mating/seat outside diameter of 2.125 in, and an inside shaft bore of 1-1/2 in. Material details specify a carbon primary ring, ceramic stationary seat, ceramic mating ring, Buna‑N elastomer, and stainless steel components for springs and hardware. The seal is rated for up to 230 psi and temperatures up to 225 °F, and it functions as an unbalanced, bi-directional seal suitable for a range of pump configurations. Common applications include pool and spa pumps, centrifugal pumps, and well point pumps, making BSP-758 a widely used replacement within Berliss’s mechanical seal lineup for standard pump geometries.