Saugstutzen | Schlammpumpen-Teile | ATF

Throatbush Liners: Critical Suction-Side Protection

The throatbush (also called suction liner or suction-side liner) is a precision wear component positioned at the pump suction inlet between the suction cover and the impeller eye. It forms the critical clearance gap—typically 1 to 2 mm depending on pump frame size—with the impeller suction shroud, and this gap is the single most important dimensional parameter controlling internal recirculation and pump hydraulic efficiency. As the throatbush wears and this clearance increases, progressively more slurry recirculates from the high-pressure discharge side back to the suction, reducing effective flow rate, lowering developed head, and increasing power consumption per unit of useful work. ATF manufactures aftermarket throatbush liners from A05 high-chrome white iron (Cr27, 600–650 BHN), A07 Cr27Mo (650–700 BHN) for corrosive-abrasive environments, A49 hyperchrome (700+ BHN) for extreme abrasion, and natural rubber (R55 at 55 Shore A, R26 at 40 Shore A) for fine-particle applications, all held to tight bore tolerances.

In abrasive slurry service, the throatbush experiences severe erosion from high-velocity flow entering the impeller eye at velocities that can exceed 8–15 m/s depending on pump size and flow rate. Particle trajectories concentrate wear at two primary zones: the inlet bore where flow accelerates into the impeller suction eye, and the back face where recirculating slurry leaking through the impeller-to-throatbush gap creates turbulent, high-energy erosion patterns. The back face is particularly vulnerable because recirculation velocity increases as the clearance gap widens, creating a self-accelerating wear mechanism. ATF manufactures aftermarket throatbush liners engineered to OEM specifications for all major slurry pump brands, with critical bore dimensions, back face geometry, O-ring groove locations, and mating surface profiles verified by CMM inspection against original equipment drawings. Proper dimensional accuracy ensures that the designed clearance is achieved on installation, maximising pump efficiency from day one of the service interval.