First, the spiral tube material
Q235A, Q23b, 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb. Q345 L245 L290 X42 X46 X70 X80 X95
Second, the spiral tube production process
It is a spiral seam steel pipe which is made of steel coiled coil as raw material, which is often heated and extruded, and welded by automatic double-wire double-sided submerged arc welding process.
(1) The steel head and tail are butt jointed, and the single wire or double wire submerged arc welding is used, and the automatic submerged arc welding repair welding is adopted after the steel pipe is rolled.
(2) Before forming, the strip is leveled, trimmed, planed, surface cleaned and pre-bent.
(3) The weld gap control device is used to ensure that the weld gap meets the welding requirements, and the pipe diameter, the amount of misalignment and the weld gap are strictly controlled.
(4) After cutting into a single steel pipe, the first three inspections of each batch of steel pipe shall be subjected to a strict first inspection system to check the mechanical properties, chemical composition, fusion condition, surface quality of the steel pipe and non-destructive testing to ensure the pipe making process. Once qualified, it can be officially put into production.
(5) The part of the weld with continuous acoustic flaw detection mark, after manual ultrasonic and X-ray review, if it is defective, after repairing, it will pass the non-destructive test again until it is confirmed that the defect has been eliminated.
Third, the characteristics of the spiral tube and its standard classification
Spiral tube has strong pressure bearing capacity and good plasticity, which is convenient for welding and processing. Generally, spiral submerged arc welded steel pipe (SY5037-83) for low-pressure fluid transportation is made of double-sided automatic submerged arc welding or single-sided welding for water. Submerged arc welded steel pipes for general low-pressure fluid transportation such as gas, air and steam. Spiral submerged arc welded steel pipe (SY5036-83) for pressure fluid transportation is mainly used for conveying oil and natural gas pipelines; spiral seam high frequency welded steel pipe (SY5038-83) for pressurized fluid transportation, using high frequency lap welding Welded, high-frequency welded steel pipe with spiral seam for pressurized fluid transport.
The spiral tube is compared to a straight tube of the same length. High production efficiency, low cost and fast growth. The strength of the spiral tube is higher than that of the straight seam tube. It is possible to produce a welded pipe with a larger diameter with a narrow blank, and it is also possible to produce a welded pipe with a different diameter by using a blank of the same width. Therefore, most of the smaller diameter welded pipes are straight seam welded, and the large diameter welded pipes are mostly spiral welded. The principal stress of the straight seam pipe is perpendicular to the deflection of the pipe with the lowest resistance to attack, while the spiral pipe staggers the deflection of the pipe with the lowest resistance to attack, which makes the long wind of the spiral pipe weld become an advantage.
This ruler is a vernier caliper with a diameter of the root of the external thread and the diameter of the taper hole of the internal thread. The most effective way to perform the identification of the thread of the spiral pipe is to operate the ruler. The manipulation is simple, intuitive and correct. In addition, it is also possible to directly manipulate the long-foot vernier caliper to connect the steel ruler to measure the outer diameter, length, and internal thread taper diameter of the external thread to check the thread size.
Fourth, the cause of the wrong side of the spiral tube
When the spiral tube is produced, the wrong side occurs, and there are many influencing factors. In the production practice, the steel pipe is often downgraded by the dry and wrong side. Therefore, it is necessary to analyze the causes of the wrong side of the spiral tube and its preventive measures. In the spiral tube forming, the boring of the steel strip will constantly change the forming angle, resulting in a change in the weld gap, resulting in a slit, a wrong side or even a lap. Seriously affect the quality of the steel pipe, so observe the bending of the steel drum after the unwinding of the coil, by controlling the vertical roller to cut the part of the boring tool and the continuous control and correction of the forming angle is to reduce the steel belt boring in the production process An effective way to create a wrong side.
1. The poor condition of the edge of the steel strip is another important cause of the wrong side.
2. Due to the poor shape and dimensional accuracy of the uncut edge steel strip, it is easy to cause the steel strip to bend hard and cause the wrong side.
3. The sickle bend of the steel strip is the most important factor causing the wrong side of the steel pipe.
4. When the residual height of the butt weld of the steel strip is large, it may cause a large misalignment if it is improperly handled during overmolding.
Hydraulic Hose Fittings,Metric Hydraulic Hose Fitting,NPT Male Hose Fitting,Reusable Hose Fitting
Hydraulic Fitting,Threaded Adapter Co., Ltd. , http://www.xindawind.com