SSP lobe pumps are the premier rotary lobe pump for sludge applications including digester feed, centrifuge feed, press feed, recirculation, RAS and WAS. Our pumps can handle solids concentration up to 8%. The key to our pumps’ longevity is the AIR-GAP. A physical separation between the pumphead and gearcase which allows visual inspection of the mechanical seal, and allows the customer to use his preferred brand and type of seal. Less expensive pump brands couple the pumphead directly to the gearcase resulting in catastrophic failure whenever a mechanical seal leaks. SSP sludge pumps include urethane coated rotors with slotted tips. The slotted tips allow for the safe transmission of grit and solids through the pump without scoring or causing wear to the pump internals. Additionally the SSP pump has four bearings per shaft (compare with 2 per shaft on cheap brands), plus we fix the rotors onto the shafts via involute splines which last much longer than the keyways used by other brands. SSP pumps are truly built to last with some installations running continuously since the 1980s.