Pile Band Production
1.The cutting face should be flat.
2. Permissible cutting length error of +0.5 mm.
3. Select one piece from every 10 samples for test to ensure complete welding of end plate, avoid loose weld caused by tensioning.

Cold Drawn production
1.Q235B materials, Φ6.5 low carbon hot-rolled rods
2. Pull low carbon hot-rolled rods with a wire drawing die,, remove the oxide layer to ensure weld ability.

Cutting
1.Steel bar cutting length error: cutting length less than 15m, error ≤ 1.5mm;cutting length more than 15m,error ≤2.0mm.Flash burr is not allowed.
2. Randomly select three pieces from each sampling and check the cutting length to ensure stability.

Heading
1.Head cap should be round shaped, no skew and crack.
2. Head strength should not be less than 95% of the standard strength.
3. Randomly select not less than 10 pieces a day to test its heading strength; select not less than 2 pieces in the case of brand and changing to avoid pull off of the head.

Cage making
1.Prestressed main reinforcement should uniformly distributed along  its  circumference, the minimum reinforcement ratio of  not less than 0.4%, and the number of not less than 6 space deviation of ± 5mm.
2. Spiral reinforcement spacing for dense area of 45mm, non-dense area of 80mm.Dense length is 2m to 3m, dense number is 3 to 4.
3. Welding bars should not be too burnt and damaged to ensuring the integrity of the skeleton.
4. When roll-welding the spiral bar ,regularly test the daily production of each specification cage bars to ensure the suitable
5. Fix a number card in every finished cage to trace the test data and application process of every pile.

Assembling
1.gently hang steel bars into the mold to avoid deformation. Place them straight and parallel with the mould edge to assemble both ends of the plate.
2. Make sure that the main steel bars completely into the counterbore when assembling the end plate.
3. When assembling the stern flap and tension ring, first cast waste oil in the thread and turn a few laps with hand, then tighten it with air trigger using the opposite angle method.
4. Brand and shape the cage after assembling to make them close to the inner mold wall. Keep the flatness of the main reinforcement and band the loose spiral reinforcement. Only the qualified cage could be hanging to the fore-platform for material distribution.

Feeding
1.Feeder electronic valve could evenly control the speed through a regular opening and closing; while the uniform motion of the flat car could make the fresh concrete distribution evenly; to ensure the  quality of the end plate, make a short duration of  stay when distribute the fresh concrete.
2. Mixing Station control room could calculate the dosage and the number of slots according to the pile length and the model, making the distribution more rational and scientific.
3. Certain workers are appointed responsible for the distribution process in the two ends. It is required a relatively pump process to avoid separation of the sand and stone.

Moulding
1. Check the wheel rim and the mold end to avoid offset. Remove the impurity with a small shovel or other tools in the mouth of seam.
2. Handle with care when closing the mould.
3. After molding, check the screw to avoid damaged or not been tightened to ensure that there is no transudatory serosity phenomenon in the centrifugal process.

Tensioning
1.Before the deduction of tensioning, fasten the tension flange to make the tension machine and the mould in the same axis.
2. Tensioning process must be carried out slowly to ensure at least three stops and keep a steady voltage of 30S to prevent fracture of the main reinforcement.
3. Extension value combined with tensioning oil pressure value will be tracked in the whole process to make “dual control”. Dominated by oil pressure, supplemented by extension value, therefore preventing less or pull over.
4. Our tension machine fastened the tension ring to the tension flange in a uniform force to effectively prevent the tilting of the end plate caused by tilt tensioning.

Centrifugation
1.Five grade spinning process and adequate spinning make the internal structure more dense.
2. Centrifugal process could effectively ensure concrete strength, improve endurance of the pile.
3. Centrifugal operator will record the whole process in detail.
4. Centrifuge speed will be regularly checked (one time per month).
5. Our centrifuge machines could centrifuge up to 55 meters of pile product. Dual combinations of head and tail could effectively improve the stability of the centrifugal speed. Frequency conversion Control centrifugal parameter could not be changed once settled.

Steam curing
1. National standard of the pile relaxing concrete should be not less than 45Mpa. Our production of concrete strength (same condition curing with sample block) is controlled around 70Mpa.
2. Using steam curing from 7.5 to 8 hours, temperature 65 ℃ to 70 ℃.
3. Delaying curing 2h-heating up 2h- constant temperature 2h to 4h
4. The laboratories developed a reasonable system of steam curing and regularly monitor to ensure the smooth progress.

Demoulding
1. After clearing the model, even brushing release agents to ensure a smooth demoulding process and avoid the appearance of defects.
2. When relaxing, adopted mutual symmetrical way to avoid excessive eccentric stress which will cause bends and cracks of the piles.
3. After demoulding, laboratory will test and record the pile appearance quality and size deviation of each pile according to the latest national standards and divided them into quality grades.
4. After testing the product, print trademarks and numbers of the piles to make effective after-sales service.
5. Engraving marks in pile bodies for customers to monitor the length of pile when sinking piles.

Autoclave
1. Autoclave pressure: 0.95MPa ± 0.05MPa
2. Autoclave time: about10h
3. Boost pressure 2.5h constant pressure 3h– decompression 3.5h-open autoclave 1h
4. Same conditions curing of the specimens’ strength testing 85MPa-110MPa though curing adjustment.
5. The laboratory develops a reasonable system of steam curing, and monitor regularly to
ensure the smooth process.
6. Quality Department will check the quality on each pile and record the result after autoclave.