Xintuo Pipe Industry Quality Inspection Process: The "Health Report" of Every Pipe

In engineering projects, a single substandard steel pipe can bring an entire production line to a halt, delay a whole project, or waste hundreds of thousands or even millions of investment.

At Xintuo Pipe Industry, we understand that every steel pipe carries our customers' trust and project safety. That is why we have established an end-to-end quality inspection system covering raw material incoming, production process, and finished product dispatch. Every pipe has its own "health report."

Stage 1: Raw Material Inspection – Quality Begins at the Source

70% of pipe quality depends on raw materials. Xintuo Pipe Industry insists on sourcing Grade A stainless steel coils from renowned domestic mills such as Qingshan, Baosteel, and TISCO.

Every batch of incoming raw materials undergoes:

• PMI (Positive Material Identification): Using a direct-reading spectrometer to analyze coil composition, ensuring key elements such as Cr and Ni meet grade requirements.

• Surface and Dimensional Inspection: Checking coil surfaces for cracks, scratches, dents, and other defects.

Only coils that pass raw material inspection enter the production line. Non-conforming materials are never put into production.

Stage 2: Production Process Control – Every Step Is Monitored

From coil to finished pipe, the process involves uncoiling, forming, welding, weld treatment, heat treatment, and many other steps. Xintuo Pipe Industry's 54 online pipe-making lines are equipped with comprehensive process control measures to ensure stable quality at every step.

Welding Process Monitoring
Welding is the core process of welded pipe production. We use full argon-shielded TIG/plasma welding processes, monitoring key parameters such as welding current, voltage, and speed in real time. Weld surfaces must be free of cracks, lack of fusion, porosity, undercut, and other defects.

Weld NDT (Non-Destructive Testing)
After welding, we conduct strict Ultrasonic Testing (UT) or Radiographic Testing (RT) on the weld seam to ensure there are no internal defects such as cracks, lack of fusion, or slag inclusions. Pipes with issues are immediately identified and isolated, never allowed to proceed to the next process.

In-Line Dimensional Monitoring
During production, we continuously monitor key dimensions such as outside diameter, wall thickness, and ovality, ensuring wall thickness tolerances are maintained within standard limits and that the entire pipe wall is highly uniform.

Stage 3: Finished Product Inspection – Every Pipe Is Individually Checked

After coming off the production line, every steel pipe undergoes a complete set of inspection procedures.

Visual Inspection
Inspectors conduct visual checks on both the internal and external surfaces of every pipe, ensuring surfaces are clean and smooth with a uniform silvery-white appearance, free from cracks, folds, lamination, burrs, over-pickling marks, and other defects.

Dimensional Accuracy Inspection
Precision measuring instruments are used to measure outside diameter, wall thickness, length, ovality, and other critical dimensions on every pipe, ensuring all are within standard tolerance ranges.

Hydrostatic Test
Every pipe undergoes a hydrostatic test individually. Test pressure is applied per standard requirements and held for sufficient time to ensure no leakage. Every pipe that passes the hydrostatic test proves its reliable pressure-bearing capacity.

NDT (Non-Destructive Testing)
Per standard requirements, finished pipes undergo Ultrasonic Testing (UT) or Radiographic Testing (RT) to ensure the weld seam and pipe body are free from any internal defects, providing double assurance for pipe quality.

Stage 4: Physical and Chemical Performance Testing – Let the Data Speak

In addition to individual pipe inspections, Xintuo Pipe Industry is equipped with professional testing equipment to conduct comprehensive physical and chemical performance tests on a batch basis.

Mechanical Property Tests

• Tensile Test: Measures tensile strength (≥520MPa), yield strength (≥205MPa)

• Flattening Test: Verifies weld and pipe wall integrity under deformation conditions

• Flaring Test: Verifies no cracking occurs after pipe end expansion

Process Performance Tests

• Bend Test: Verifies the pipe's plastic deformation capacity

• Intergranular Corrosion Test: Conducted per GB/T 4334 standard to verify corrosion resistance of the weld and heat-affected zone

Metallographic Analysis
Metallographic structure analysis is performed on the weld zone to verify structural consistency between the weld and base material, as well as grain size grade.

Stage 5: Mill Test Certificate – Every Batch Has Its "Identity Card"

Before each batch leaves the factory, we issue a complete quality documentation package.

Mill Test Certificate (MTC) includes:

• Heat number/batch number (traceable to raw materials)

• Chemical composition analysis data (C, Si, Mn, P, S, Cr, Ni, etc.)

• Mechanical property test results (tensile, yield, elongation)

• Process performance test results (flattening, flaring, etc.)

• NDT reports (UT/RT)

• Hydrostatic test report (test pressure and hold time)

• Heat treatment records

Every mill test certificate is a complete "health report" for that pipe, from raw material to finished product.

Xintuo Pipe Industry's Quality Inspection Commitment

End-to-End Traceability
Every pipe has a unique traceability number. From raw material heat number to production batch, from inspection data to operator information — everything is documented.

100% Individual Inspection
Visual inspection, dimensional inspection, hydrostatic testing, and NDT — every pipe undergoes all four key inspections individually. Not spot checks, not batch sampling — every single pipe.

Multi-Standard Coverage
Our quality inspection system fully covers major domestic and international standards including GB/T 12771, ASTM A312, EN 10217-7, and HG 20537. Our products also comply with ISO 9001 Quality Management System and Pressure Piping Component Manufacturing License requirements.

At Xintuo Pipe Industry, every pipe undergoes a rigorous "final exam" before leaving the factory. This "health report" is our promise to our customers and our reverence for engineering safety.