Quality Control & Testing Protocols
Multi-stage inspection from raw ingot casting to finished threaded pipe fittings.
Our Quality Assurance Commitment
At Gripwell Pipe Fitting Industry, quality is embedded into every operational step. We understand that pipe fittings must reliably withstand internal hydraulic surge pressures, ground movement, and environmental corrosion in mission-critical piping installations.
Raw Material Inspection
Incoming scrap and pig iron ingots undergo chemical composition analysis to verify optimum carbon, silicon, and manganese levels essential for ductile, crack-free malleable castings.
Annealing & Heat Treatment
Castings are subjected to controlled heat-treatment annealing cycles to transform brittle white iron into tough, shock-resistant malleable iron with high tensile ductility.
Dimensional Inspection
Precision digital vernier calipers and micrometer gauges verify wall thickness uniformity, center-to-face dimensions, and concentricity across all fitting angles.
Thread Lead & Gauge Inspection
Thread pitch, taper angle, and depth are systematically verified using certified GO / NO-GO plug and ring gauges (BSPT / NPT) to prevent on-site cross-threading.
Surface & Galvanizing Check
Zinc coating thickness is checked using magnetic thickness gauges. Surfaces are inspected for smooth finish, devoid of sharp burrs, dross, or uncoated bare spots.
Hydrostatic Pressure Testing
Batch samples are clamped onto high-pressure test rigs and pressurized with water to confirm complete zero-leakage joint sealing under high hydrostatic stress.
Protective Packaging & Dispatch Handling
Fittings are treated with anti-rust protective oil or zinc passivated before being securely packed in heavy-duty poly-woven sacks or corrugated export cartons to prevent thread damage during road freight and container handling.
Quality Certifications & Test Reports
Mill test certificates, batch chemical analysis sheets, and pressure test observation reports are provided to commercial clients upon order execution.