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Warman®-Compatible Slurry Pump Wear Parts Guide: Impeller, Liners and Throat Bush
Wear parts — impeller, volute liner, frame plate liner and throat bush — are the consumables of a slurry pump. This guide explains what each part does and how to choose the right material.
Slurry pumps are built to move abrasive mixtures of water and solids, and their wet-end parts wear out. That is normal: the impeller, liner and throat bush are consumables, designed to be replaced. Understanding what each wear part does, how wear shows up and when to replace it saves downtime and protects the rest of the pump.
Trademark note: WARMAN is a registered trademark of Weir Minerals. HEDUN is not affiliated with or authorized by Weir. HEDUN wear parts are replacement parts, not genuine Warman parts.
Impeller — the heart of the pump
The impeller is the rotating part that transfers energy from the shaft to the slurry. Its vanes throw the mixture outward, giving it velocity and pressure. Because it spins at high speed in direct contact with abrasive particles, the impeller is usually the first wear part to need replacement. A worn impeller has rounded or thinned vanes, a larger clearance to the throat bush, and a smaller diameter at the outlet. The symptoms are a drop in flow and head at the same speed, higher vibration, and eventually cavitation damage on the vanes.
Volute liner — protecting the casing
The volute liner sits inside the casing and forms the spiral collecting chamber around the impeller. It converts the kinetic energy of the slurry into pressure and guides it to the discharge. The liner takes the impact of the slurry leaving the impeller at full speed, so its inner surface wears in a characteristic pattern, known as the cutwater and the belly. A worn volute liner leaves the impeller unsupported, increases recirculation inside the pump, and wastes energy.
Frame plate liner and cover plate liner
The frame plate liner and the cover plate liner close the sides of the casing and form the walls of the pumping chamber. Together with the volute liner they are called the liner set, or the wet-end liners. They wear by sliding abrasion and by impact at the inlet, and their thickness is the main limit on service life. Because they are large, flat parts, they are easier to inspect than the impeller: wear shows as thinning, grooves and, in the worst case, a hole worn through the liner.
Throat bush — small part, big effect
The throat bush is the ring at the pump inlet, around the impeller eye. It seals the gap between the rotating impeller and the stationary casing, and it controls leakage back from the discharge side to the suction side. It is a small part, but its clearance is critical: as the throat bush and the impeller eye wear, the gap grows, leakage rises, and the pump loses flow. A worn throat bush is one of the commonest causes of a gradual loss of performance in an otherwise sound pump.
How to identify the correct replacement part
To order the right wear part, HEDUN asks for the pump model (for example AH 4x3, AH 6x4), the part name and the material. If the model is not known, the part dimensions, a photo of the worn part, or the pump serial plate will usually identify it. Most HEDUN spares are in stock, so delivery for common sizes is short. Send a photo of the worn part, and HEDUN will confirm the match before quoting.
Wear parts for slurry pumps: casing, volute liner and frame plate liner.
High-chrome metal or rubber?
High-chrome white iron (A05, A07) is the standard choice for large particles and high impact. Its hardness resists cutting and gouging, but it is brittle and can crack under severe impact. Natural rubber (R08, R26) and polyurethane suit fine slurries, because the elastic surface absorbs impact and resists erosion from small particles. The choice depends on particle size, velocity and whether the slurry contains sharp stones. HEDUN supplies both metal and rubber lined options for the same pump.
When to replace wear parts
Replace a wear part when performance has dropped to the point where the process suffers, when vibration or leakage has increased, or when the remaining thickness is close to the minimum. Waiting too long risks a liner breaking through, which can damage the casing behind it and cause an unplanned shutdown. Keep a set of the common wear parts on site, inspect them at planned intervals, and replace the liner set together where possible: a new impeller running against a worn liner wastes the benefit of the new part.
Summary
Wear parts are the consumables of a slurry pump. The impeller, volute liner, liners and throat bush each have a job, and each wears in its own way. Knowing how to inspect them, how to identify the correct replacement, and how to choose between metal and rubber keeps a slurry pump running efficiently and avoids unplanned stops.
WARMAN® is a registered trademark of Weir Minerals. HEDUN is not affiliated with or authorised by Weir. All references to Warman® in this article describe compatibility only.
