The selection of raw materials is in line with the relevant standards of the pipe producing countries and the raw material standards required by the owner. After entering the factory, the inspectors first verify the original material certificate issued by the manufacturer and the material inspection report of the importer. Check whether the marking on the material is complete and whether it is consistent with the quality certificate to ensure that it meets the specified indicators of the material. The material required by the customer should also undergo the following tests:
Mechanical properties Mechanical properties meet the requirements of different material standards. For alloy steel pipes, do transverse mechanical performance test (including transverse impact test), the impact test is Charpy V test, and the number of inspections is the same as the tensile test.  

Select materials with sufficient margin according to the design requirements, and consider whether the stress enhancement coefficient of the pipe fittings after forming conforms to the design stress coefficient of the pipe and the flow area of the pipe. , material, pipe number, furnace batch number and pipe blank flow number and other content to do the logo transplant, the logo adopts the method of low stress steel stamp and paint spraying.) After the first piece is cut, the operator will conduct self-inspection and report to the special inspection personnel of the testing center. Carry out special inspection, after passing the inspection, other parts are unloaded, and each part is inspected and recorded on the production process flow card to record the operation conten

Clean up the debris in the furnace hall of the heating furnace, check whether the heating furnace circuit, oil circuit, trolley and temperature measurement system are normal, and whether the oil is sufficient

The thermoforming of the product fully considers the law of the metal flow of thermoplastic deformation during the molding process of the finished product. The forming mold strives to have a small deformation resistance to the thermal processing of the workpiece, and the pressed tire mold is in good condition. According to ISO9000 quality assurance system requirements Regularly verify the tire mold, control the thermoplastic deformation of the material, so that the actual wall thickness of any point on the pipe fitting is greater than the minimum wall thickness of the connected straight pipe.Put the billet in the heating furnace for heating, use refractory bricks to isolate the workpiece from the furnace table 20, strictly control the heating rate 150℃/hour according to different materials, and keep the heat preservation for more than 1 hour when heated to 30-50℃ above the material AC3 . The heating and heat preservation process is monitored by digital display or infrared thermometer, and can be adjusted at any time

 

Heat Treatment

The furnace hall of the heat treatment furnace is clean and free from oil, ash, rust and other metals different from the processing materials. Heat treatment is carried out strictly according to the heat treatment curve required by the "heat treatment process card".
The automatic recorder records the rise and fall of the temperature at any time and automatically adjusts the temperature and holding time in the furnace according to the predetermined parameters.

During the heating process of the pipe fittings, the flame is blocked by a fire wall to prevent the flame from being directly sprayed on the surface of the pipe fittings, so as to ensure that the pipe fittings will not be overheated or overburned during the heat treatment process. After heat treatment, the metallographic inspection of the alloy pipe fittings shall be carried out piece by piece. The actual grain size of the alloy shall not be coarser than grade 4, and the grade difference of the same heat pipe fitting shall not exceed grade 2.

The hardness test is carried out on the pipe fittings after heat treatment to ensure that the hardness value of any part of the pipe fittings does not exceed the range required by the standard.
After the pipe fittings are heat treated, the oxide scale on the inner and outer surfaces is removed by sandblasting until the metallic luster of the material is visible. For scratches, pits and other defects on the surface of the material, use tools such as grinding wheels to smooth them, and the local thickness of the polished pipe shall not be less than the minimum wall thickness required by the design.
Fill in the heat treatment records according to the number and identification of the flanged pipe fittings, and rewrite the incomplete identification on the surface of the pipe fittings and the transfer card

 

For the pipe fittings to be welded, the welding work is carried out by professional welders with many years of welding experience through the combination of automatic welding and manual welding, and appropriate welding procedure evaluation is carried out according to the requirements, and the mechanical properties of the weld are tested. Welding production. The welding process adopts qualified welding procedure qualification and cannot be welded. During the welding process, the quality assurance engineer shall monitor and measure the stop points and witness points of the welding process to ensure that there are no defects and problems in the key process of welding. In the welding of alloy materials, welding parameters such as interlayer temperature, preheating temperature, and number of welding layers are strictly controlled, and careful interlayer cleaning is carried out. Tempering treatment is carried out immediately after welding to ensure that the performance of the welded joint meets the specification requirements.

 

The welding process is carried out in strict accordance with the "Welding Process Guidance Card" formulated by the company. During the welding process, attention should be paid to avoid defects such as incomplete penetration, pores, ballast, cracks, and undercuts.

The post-weld heat treatment of the pipe fittings can be carried out in a resistance furnace or an oil-fired furnace, or in a far-infrared heating furnace to ensure that the welded joints have mechanical properties and other technical indicators similar to those of the base metal.
The welding seam of welded pipe fittings shall be tested by 100% ray or ultrasonic wave. According to the standard of JB4730-2005, the ultrasonic reaches grade I, and the ray reaches grade II.

 

Surface Quality. The inner and outer surfaces of the pipe fittings are not allowed to have defects such as cracks, shrinkage holes, slag, sticky sand, folding, missing welding, heavy skin, etc. The surface should be smooth, no sharp scratches are allowed, the depth of the depression does not exceed 1.5mm, the maximum size of the depression is It should not be greater than 5% of the circumference of the pipe, and not greater than 40mm. There shall be no cracks, pores, arc craters and spatters on the surface of the weld and no undercuts, and the inner corners of the tee shall have a smooth transition. All pipe fittings do 100% surface appearance inspection. Cracks, sharp corners, pits and other defects on the surface of the pipe fittings shall be ground with a grinding machine, and magnetic particle inspection shall be carried out on the grinding place until the defects are eliminated. The thickness of the ground pipe fittings shall not be less than the minimum designed thickness.

All of the welding seam of welded pipe fittings shall be subjected to radiation. Flaw detection or ultrasonic flaw detection. Forged tees or elbows are ultrasonically inspected on the billet before machining.

Magnetic particle inspection shall be carried out within 100mm of the groove of all pipe fittings to ensure that there are no defects such as cracks caused by the cutting process at the groove

 

For the pipe fittings with special requirements of customers, the following tests should be done:
Hydraulic test All pipe fittings can be hydraulically tested with the system (the hydraulic test pressure is 1.5 times the design pressure, and the time is not less than 10 minutes). Under the condition that the quality certification documents are complete, the pipe fittings delivered from the factory may not be subjected to the hydrostatic test.

 

  Final Inspection

 

The surface of the pipeline should be coated with anti-rust primer, and the surface should be painted with different colors according to different pipes. The paint is uniform, no bubbles, no wrinkles and peeling phenomenon, and the groove is treated with a special anti-rust agent.

 

Q/A or Q/C inspection the final flange and pipe fittings products dimension, wall thickness , surface painting and marking packages details

Final document

 

Before the product is delivered, various quality records and reports, as well as technical documents, shall be reviewed according to regulations, which can be reviewed by the owner before delivery. The documents to be submitted with the goods are: Quality Assurance Certificate, design parameters of processed parts, design drawings, and inspection reports of pipe fittings

A Raw material re-inspection report;

B RT report;

C Heat treatment report;

D Ultrasonic inspection report;

E Magnetic particle inspection report;

F Coloring report Penetration inspection report;

G Geometric dimension inspection report;

H Various reports made in consultation with users

Other necessary documents for the material and weight of pipe fittings.

Services Type	Final Inspection Services
Third party inspection	Independent Inspection Highly Professional QC Services
Quality inspection	International Standards
Senior Inspectors	Inspectors 10 Years Experience
Production monitoring	Constant Valuable Feedback
Inspection Place	Chinese Cities
Factory audit	Selected
Service time	7x24 hours
Issue Report Time	Within 24hrs
Guarantee	Satisfied