Quality Control

We commit to consistent product quality, on-time delivery, and continuous improvement. Quality is measured by defect-free parts, accurate dimensions, and reliable performance in service. We follow documented procedures and keep records for traceability.

Our quality system follows ISO-style principles. Documented procedures cover incoming material, production control, inspection, calibration, nonconforming product, and corrective action. Records are retained for traceability and audit.

We use a four-stage inspection flow. IQC checks raw materials. IPQC monitors casting and machining in-process. FQC inspects finished parts. OQC performs final checks before packing and shipment. Each stage has clear checkpoints and acceptance criteria.

All incoming materials undergo verification. We check material certificates, chemical composition by spectrometer, and visual condition. Each lot receives a batch number and is quarantined until approved. Supplier COAs are filed with material records.

IPQC covers wax patterns, shell strength, pouring parameters, heat treatment, and machining stages. Operators follow work instructions and record key parameters. Inspection points include wall thickness, dimensional features, and seal surfaces. Nonconforming findings trigger immediate containment.

FQC inspects critical dimensions, threads, sealing faces, and finishes. We verify tolerances, surface roughness, and thread fit. Each part is checked against customer drawings and the internal inspection checklist. Critical parts receive 100% inspection; others follow sampling plans.

OQC confirms packing, labeling, documentation, and quantity. Pressure or leak tests are performed when required. Packaging is inspected for protection standards needed for sea or air transport. A packing list and inspection report accompany each shipment.

We use calibrated instruments: spectrometer, CMM, hardness tester, surface roughness tester, micrometers, calipers, thread gauges, torque testers, and pressure/leak test rigs. Calibration records are maintained. Instruments are calibrated on a regular schedule.

Dimensions are controlled to customer drawing or internal tolerance tables. Typical casting tolerances: CT5–CT7. Machined tolerances specified per drawing. Critical sealing faces and thread fits are verified with gauges and CMM reports.

We perform hardness tests, hydrostatic/pressure tests, and thread torque tests as required. Pressure tests follow customer or standard test pressures. Test reports are saved with batch records.

We inspect surface finish, blasting, polishing, and passivation. Corrosion-sensitive parts are passivated and tested for correct treatment. Surface roughness targets are recorded on inspection reports.

Every casting batch and machined lot carries a unique ID. Records link material lot → casting batch → machining order → final packing. Traceability enables root-cause analysis and fast recall if needed.

Nonconforming items are segregated and logged. A documented disposition path includes rework, concession, or scrap. Corrective actions are assigned and tracked to closure.

Sampling follows ISO 2859-1 (or customer-specified plans). Typical AQL for critical parts is 0.65–1.5, depending on application. For critical sealing or safety parts, we use tighter inspection or 100% inspection.

All inspection and test equipment are on a calibration schedule. Calibration certificates are kept. Equipment out of tolerance triggers a review of affected parts and possible reinspection.