Every SlurryPro pump can be built or lined in a range of metallic and polymeric materials, and two of them cover the majority of duties: rubber, our 360 material, and high-chromium alloy, our 331. Choosing between them is a quiet decision that ends up setting your wear life, your running costs and how often the crew are pulling the wet end apart.

It is not a question of which material is better. It is a question of what your slurry is doing — particle size and shape, temperature, chemistry and duty — and matching the material to that.

Rubber does not resist wear by being hard

This is the part that catches people out. Rubber survives abrasive service by being resilient rather than hard. When a small, rounded particle strikes a rubber liner the surface deforms locally, and because the elastomer has high resilience most of that energy is handed back to the particle as it rebounds, instead of being spent cutting and gouging the surface.

That is why rubber does so well on fine, rounded solids — silica sands, fine tailings, high-concentration slurries where the particles are small enough to bounce. It is also lighter and lower cost than a metal wet end, which makes it the sensible default when the duty allows it.

Where rubber stops making sense

Rubber has three clear enemies. Heat is the first: above roughly 100 °C it is not appropriate, and high chrome takes over. Sharp, angular or oversized particles are the second — those cut the surface rather than bouncing off it, and no amount of resilience helps. Speed is the third: high impeller tip speeds, typically on larger and faster pumps, degrade rubber quickly, and industry guidance generally puts the practical ceiling somewhere around 27 m/s.

High discharge head belongs on the same list. Past about 70 m a rubber impeller is being asked for more than it can safely give. Hydrocarbon or oil content is a separate question again — rubber can be attacked chemically, so oily sludge needs a compatibility check before you commit.

Where high chrome earns its place

High chrome is the answer when the duty is genuinely severe: high temperatures, high pump speeds, large or sharp solids, and high discharge pressures. It is a hard metal that resists cutting wear, and on coarse, aggressive material it will comfortably outlast rubber.

The trade-off runs the other way on fine material. Put high chrome into a fine silica sand duty and it wears at a high rate — the fine particles that would bounce harmlessly off rubber are quietly abrading metal instead. Specifying high chrome everywhere because it sounds tougher is a common and expensive mistake.

Hybrids and exotic alloys

The two do not have to be an either-or. A hybrid build — a rubber-lined volute with a high chrome impeller — is a genuinely good answer where the discharge head demands the pump run faster than a rubber impeller can take, but the casing is not seeing the same punishment.

For corrosive duty where neither standard option is compatible, there are exotic and special alloys: stainless SS-316L for corrosive duties with moderate abrasion, duplex stainless where corrosion resistance needs extra strength behind it. These are the reserve option rather than the first pick — if a rubber or high-chrome build will do the job, it usually should.

The short version

Fine, rounded particles at moderate head and temperature: rubber. Coarse, sharp, hot, fast or high-pressure: high chrome. Corrosive fluids: check compatibility properly and consider an exotic alloy. Head above 70 m or temperature above 100 °C: rubber is out.

You are not locked in

One of the better features of the range is that liners and impellers are interchangeable, so you can change material in the field without swapping the whole pump. If your material changes, or the duty shifts, or your first choice is wearing faster than it should, the wet end can follow it.

As always, confirm the final choice with your pump supplier before you order. The guidance above will get you to the right neighbourhood, but the details of your slurry are what settle it.