Materials, Linings and Wear
Protection for Conveying Bends

Choose Body, Contact Surface and Reinforcement Separately

A conveying bend can contain more than one material. The outer body carries structural loads, a liner or overlay may form the wear surface, and joints, gaskets or adhesives complete the assembly. A claim about one constituent’s hardness, temperature capability or corrosion resistance does not establish the limit of the whole elbow.

Cast Carbon Steel and Cast Aluminium

The pocket-elbow program includes cast carbon steel and cast aluminium. Cast steel can offer strength and compatible connections where the operating and corrosion conditions permit it. Aluminium can reduce body weight, but the alloy selection and casting design need review for abrasion, pressure, temperature and handling.

For cast products, the technical drawing should identify an actual material specification and mechanical properties—not only a generic “steel” or “aluminium” label.

Cast 304-Type and 316-Type Stainless Steel

Cast stainless steel is not described most accurately by a wrought AISI designation alone. Potential grade descriptions include CF8 (304-type) and CF8M (316-type) where approved by the manufacturing specification. The final certificate must identify the real casting grade, heat treatment and required inspection. Corrosion suitability depends on the process and cleaning chemistry.

Fabricated Carbon Steel, AISI 304 and AISI 316

The five pipe-based launch families use carbon steel, AISI 304 or AISI 316 as proposed base pipe/shell materials. Actual pipe standards, surface finish, welding, wall thickness and post-fabrication treatment are selected by duty. The material selection is independent of whether ends are plain or flanged.

Basalt Wear Protection

Basalt-based wear surfaces are candidate protection for specified abrasive service. The final design must document whether Polimak uses cast basalt elements, segments, a deposited coating or another qualified construction. The supporting metal, bond/retention method and internal joint geometry must be evaluated alongside basalt wear characteristics.

Ceramic Wear Linings

Common industrial ceramics include alumina and silicon carbide, but their performance depends on actual grade, porosity, impact loading, liner thickness and retention method. These are industry examples, not a list of approved PneuBend stocked ceramic grades. The quotation should specify the approved formulation and complete installation arrangement.

Tungsten Carbide Hardfacing

A tungsten-carbide-containing weld overlay is applied to a compatible metal substrate using a qualified procedure. Hardness alone does not define service performance: matrix composition, carbide distribution, overlay thickness, coverage and susceptibility to cracking all matter. Carbon steel and stainless substrates may require different procedures.

Liner Thickness and Final Internal Bore

Protective layers occupy space. The designer should state the minimum clear bore after protection, any interface steps and the relationship to the adjoining pipe. More wear layer is not always better if it creates excessive local velocity or restricts the line.

Material Compatibility and Testing

Define the material conveyed, carrier gas, moisture, abrasion, impact, temperature and cleaning method. Where a comparative trial is practical, measure product degradation, pressure demand and wear over comparable conveyed quantities. Exact certificates or regulated-contact documentation should be requested by model and revision.

Compare the six families · Request a material review.