Pump Casing: Size Range DN25 to DN500

Component Specifications

Definition

A pump casing is a critical component in centrifugal pump assemblies that encloses the impeller and volute, converting kinetic energy from the impeller into pressure energy. It maintains proper fluid flow direction, minimizes turbulence, and withstands internal pressure and external loads. Casings are designed with specific hydraulic profiles to optimize efficiency and are manufactured to precise tolerances to prevent leakage and ensure reliable operation in industrial applications.

Working Principle

The pump casing operates on the principle of converting velocity energy to pressure energy. As fluid exits the rotating impeller at high velocity, it enters the casing's volute or diffuser section where the gradually expanding cross-sectional area reduces fluid velocity, increasing static pressure according to Bernoulli's principle. The casing also provides a controlled flow path that minimizes hydraulic losses and directs fluid to the discharge outlet.

Materials

Typically cast iron (ASTM A48), ductile iron (ASTM A536), stainless steel (AISI 316/304), bronze (C83600/C84400), or engineered polymers for corrosive/abrasive applications. Material selection depends on fluid compatibility, pressure requirements, and environmental conditions.

Technical Parameters

Parameter	Typical range	Notes & selection driver
Size Range	DN25 to DN500
Surface Finish	Ra 3.2 μm typical
Pressure Rating	Up to 25 bar (standard)
Connection Types	Flanged, threaded, or grooved
Temperature Range	-20°C to 150°C
Dimensional Tolerance	IT8-IT10

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Standards

ISO 5199, ISO 2858, DIN 24255, ANSI/ASME B73.1

Parent Products

This component is used in the following industrial products

High-Flow Pump Assembly

A high-capacity pumping unit designed for rapid fluid delivery in emergency cooling applications.

View Product Details

Engineering Analysis

Risks & Mitigation

Cavitation damage from improper NPSH
Corrosion from incompatible fluids
Mechanical stress from pressure surges
Erosion from abrasive particles
Thermal expansion mismatch

FMEA Triads

Trigger: Cavitation due to insufficient NPSH
Failure: Pitting and material erosion on casing walls
Mitigation: Ensure adequate NPSH margin, install inducer, or use cavitation-resistant materials

Trigger: Chemical corrosion from process fluids
Failure: Wall thinning and eventual leakage
Mitigation: Select compatible materials, apply protective coatings, implement corrosion monitoring

Trigger: Thermal cycling stress
Failure: Cracking at stress concentration points
Mitigation: Design with uniform wall thickness, use materials with matching thermal expansion, implement gradual temperature changes

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance

Dimensional tolerances per ISO 2768-m, pressure containment per ASME BPVC Section VIII

Test Method

Hydrostatic pressure testing at 1.5x design pressure, dimensional inspection via CMM, material verification through spectroscopy

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

Technical documentation

Request current drawings, revision history, and a signed specification sheet.

Manufacturing capability

Verify equipment lists, process limits, capacity, and representative production evidence.

Inspection readiness

Confirm test methods, calibrated equipment, sampling plans, and traceable reports.

Supplier transparency

Check the legal entity, factory address, ownership, certifications, and direct contacts.

CNFX does not score or rank suppliers. Buyers must verify all claims and documents with the legal manufacturer before ordering.

Manufacturers of Pump Casing

1 company lists this product among what they make. Company figures are quoted from each company's own website; every card states where the relationship came from.

Shijiazhuang Industrial Pump Factory Co., Ltd.

Hebei, CN

Also makes: Power Plant, Industrial Chemical Filtration Press, Centrifugal Pump

Listed on the company's own website · profile compiled by CNFX from public sources

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Manufacturer listings support early research and capability understanding. They are not certification, ranking, or transaction guarantees.

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Shaft Bearing

Precision component supporting rotating shafts in vibration motors to reduce friction and maintain alignment.

Seal Groove

Precision-machined groove in aluminum bearing housings designed to accommodate sealing elements for fluid containment and contamination prevention.

Frequently Asked Questions

What are the main types of pump casings?

The two primary types are volute casings (spiral design for constant velocity) and diffuser casings (multiple vanes for high-pressure applications). Volute casings are most common in industrial centrifugal pumps.

How does casing wear affect pump performance?

Casing wear increases internal clearances, causing recirculation losses, reduced efficiency (5-15% drop), vibration, and potential cavitation damage. Regular inspection and maintenance are essential.

Can pump casings be repaired or must they be replaced?

Minor erosion or corrosion can often be repaired with epoxy compounds or weld buildup, but severely damaged casings typically require replacement to maintain hydraulic efficiency and structural integrity.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records. See the editorial policy.

Preliminary Technical Classification

This page supports structured research, RFQ preparation, and supplier evaluation. It does not replace buyer-led supplier qualification, standards review, or technical approval.

Pump Casing