Design & Quality Control

Safety by Design

NCPI’s priority for any new mill supply is to ensure that the mill is designed to adhere to the project design specifications as well as conservative design limits.

NCPI follows stringent, conservative design guidelines in-line with international best practice, as well as implementing an in-depth quality control plan to ensure the manufactured components adheres to the design and drawings.

To this end, NCPI adheres to the following design protocols as a minimum for all major mill components:

MILL SHELL AND HEADS

The mill shell and heads are rotating components subjected to cyclic stresses, making fatigue life the primary design consideration. NCPI follows the AAC323001 design code, based on the British standard BS7608, to assess fatigue strength. A Finite Element Analysis (FEA) is conducted using Ansys software to evaluate maximum stress and principal stress ranges, which are compared to allowable values to determine suitability. All critical mill fasteners are also evaluated per internationally acceptable standards.

GEAR AND PINION

The pinion and gear are designed using AGMA specific standards, ensuring tooth strength and pitting resistance for the full motor power. In addition, NCPI ensures gear tooth quality according to AGMA standards. Materials are selected based on field experience.

GEARBOXES AND COUPLINGS

NCPI sets strict criteria for new gearboxes, requiring compliance with AGMA standards. Coupling guards are provided for both low and high-speed couplings.

QUALITY CONTROL

To ensure the suitability of all designs, NCPI follows stringent quality control procedures that make certain each component is acceptable to NCPI standards.

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NCPI operates in accordance with ISO9001 principles.

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All NDT undertaken by independent RSA NDT technicians at specified Hold Points.

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All Hold Points are inspected by NCPI Project Engineers & QA inspectors. These include: Casting Processes, NDT, Fettling, Workpiece Set Up, Final Machining, Gear Cutting, Work-piece Run Outs, Dimensional Inspections, FAT, Sandblasting, Painting and Packaging.

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Vendor Data Report document control management.

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Quality Control Plan (QCP) for every component manufactured.

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Full Manufacturing Data Report (MDR) issued on project completion.

MECHANICAL DESIGN

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FEA Structural Analysis, Completed in house – allowable to Anglo American stress limitations (In accordance with AAC323001 specification).

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Trunnion pad and sleeve bearing design using fluid film and FEA techniques in accordance with BS7608 specifications.

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Gearbox Design submitted for NCPI review to AGMA 2001:C95. NCP specify a SF of between 2.0- 2.3.

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Bearing life L10basic >52,000hrs. Pinion Bearing life L10h > = 100 000 hours.

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NCPI Specification stipulates Couplings SF > 2.0

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Open gearing designed according to AGMA 6014: B15 and AGMA 321.05.

E & I DESIGN

Comprehensive Electrical, Instrumentation & control system design services.
Expert management and third party review of VSD and main drive motor designs – including Factory Acceptance Testing, design and manufacture.
Detailed PLC design & implementation with precise E&I interface management.