Centrifugal Pump Casing Casting

The Centrifugal Pump Casing Casting is a critical structural component designed to convert the rotational energy of impellers into hydraulic pressure in centrifugal pump systems. Manufactured from high-strength stainless steels (304/316/316L, UNS S30400/S31600/S31603) or nickel-based alloys (Inconel 625, UNS N06625) via sand casting or investment casting, these casings feature spiral volute designs optimized for minimal hydraulic loss and maximum efficiency. Engineered to withstand high-pressure fluid dynamics and thermal expansion, the casings meet international standards such as API 610, ISO 5199, and ASME B16.5, ensuring reliability in diverse industrial applications.

The casing’s internal geometry is precision-machined to tight tolerances (±0.1mm), with smooth surfaces (Ra ≤ 3.2μm) to reduce turbulence and improve flow uniformity. Available in single-stage or multi-stage configurations, they are suitable for handling clear liquids, low-solids slurries, and corrosive media, with optional coatings for enhanced wear resistance.

The pump casing is the main body of the pump, playing a supporting and fixed role. At the same time, it uniformly directs the liquid into the impeller to enable energy conversion, reducing the flow rate and transforming it into pressure energy. Our manufacturing process ensures smooth surfaces and tight tolerances, which are essential for achieving optimal pump casing performance.

Hydraulic Efficiency Optimization: CFD-analyzed volute profiles with expanding cross-sections minimize pressure pulsations and recirculation, achieving up to 90% hydraulic efficiency in clean water and 85% in slurries (≤5% solids by volume).

High-Pressure Resistance: Cast from low-carbon stainless steels with yield strengths ≥205 MPa (304) or ≥240 MPa (316L), the casings withstand operating pressures up to 100 bar (1,450 PSI) and temperatures from -50°C (-58°F) to 450°C (842°F).

Corrosion Resistance Matrix: 316L casings resist chloride-induced pitting (≤1,000 ppm Cl⁻), while Inconel 625 variants handle aggressive media like sulfuric acid and seawater (≥35,000 ppm Cl⁻), eliminating external lining needs.

Modular Design for Easy Maintenance: Split-case designs with bolted covers allow quick access to impellers and seals, while replaceable wear rings in the casing bore extend service life by 20% in abrasive environments (≤100μm particle size).

The centrifugal pump casing encloses the impeller in a confined space, allowing the liquid to be drawn in and expelled through the action of the impeller. This enclosed space facilitates the circulation of the liquid. The pump casing collects the liquid discharged between the vanes, and the liquid flows through the casing along a gradually expanding volute-shaped channel. This design converts the kinetic energy of the fluid into static pressure energy while minimizing energy loss.

Centrifugal pumps are widely used in various industrial applications, and the pump casing is one of the most critical components of centrifugal pumps. In industries such as petrochemicals, agricultural irrigation, and marine engineering, centrifugal pumps enable efficient and safe fluid transportation, providing strong support for the development of various sectors.

Water Treatment Plants: Used in primary and secondary pumps for desalination, chlorination, and wastewater recycling, with 316L casings ensuring compliance with NSF/ANSI 61 for potable water.

Petrochemical Industry: Deployed in process pumps for transferring crude oil, solvents, and polymers, where Inconel 625 casings resist stress corrosion in high-temperature, high-pressure hydrocarbon services.

Power Generation: Integral to boiler feed pumps and condenser circulating pumps in thermal power plants, handling superheated water (300°C/572°F, 150 bar/2,175 PSI) and maintaining structural integrity under thermal cycling.

Mining & Minerals: Forms the core of slurry pumps for ore processing, with hardfaced volute tongues (Stellite® 6) enduring erosion from silica particles and ensuring consistent flow rates in abrasive environments.

Q: What is the difference between sand casting and investment casting for pump casings?

A: Sand casting is ideal for large casings (up to 1,000kg) with simple geometries, offering cost efficiency; investment casting provides higher precision (±0.05mm) and complex shapes for small-to-medium casings (≤50kg).

Q: Can these casings be used with non-stainless steel impellers?

A: Yes, but galvanic corrosion may occur in mixed-metal systems. Sacrificial anodes or dielectric couplings are recommended to protect against electrochemical reactions.

Q: How is the casing tested for structural integrity?

A: Hydrostatic testing at 1.5x the rated pressure for 30 minutes is standard. Critical applications undergo ultrasonic testing (UT) and radiographic testing (RT) to ensure defect-free casting.