Characteristic Analysis Of Seamless Extrusion Titanium Pipe Fitting
Characteristic analysis of seamless extrusion titanium pipe fitting
1. Titanium pipe fittings mainly include elbow, tee, reducing pipe, etc. (size head), looping sleeve, flange, lap joint (flanging), pipe cap, etc., usually connected by butt welding.Welding connection will result in welding seams. In the process of use, when corrosive liquid flows through, the welding joints of pipe fittings will undergo force and erosion, which is likely to cause premature damage of pipe fittings due to corrosion and affect the life of the whole pipe.The following focuses on titanium elbow as an example to do a detailed description.
2. The traditional titanium elbow is mainly divided into the following types :(1) multi-weld type, (commonly known as shrimp waist type) titanium elbow, as shown in the figure below.Often used to cut the tube into many segments oblique mouth, welded together or plate under section into many material, coiling welded again, this approach leftover bits of material is more, a large quantity of weld. Because of the weld will greatly reduce the corrosion resistance, easy to leak, and poor appearance, inner surface to surface, the pipe resistance and increase the erosion and reduce the life of the back.
(2) pressure plate welding type elbow. Compared with the multi-seam "shrimp waist" type, it has less welding seams, but the pressure plate process is more complex, requiring a large number of molds.
(3) cast elbow. Although it is a seamless elbow, the wall thickness (at least 5mm) cannot match the pipe wall thickness (2mm ~ 4mm), thus increasing the transmission resistance.
(4) the stamping elbow. The elbow outward appearance and elbow push system seems to be no difference, but the process is the tube billet in the press machine stamping die stamping molding. The molding process of elbow back tension, and forced back thin, compression of the medial wall thickening and cause uneven wall thickness or crinkle. And bend back to withstand erosion in use process, because the back wall of the thin easy early damage, make pipe whole life is reduced greatly.
The above titanium elbows are far from meeting the current requirements, and the reason why push titanium elbows are quickly accepted and welcomed by users is that push titanium elbows have their own characteristics.
Processing of titanium elbow push system based on titanium seamless pipe as blank, the push system of extrusion machine adopts the pipe diameter is less than the finished product diameter of billet pushing system, extrusion forming process of tube billet by expansion (as shown in figure 3). In the process of forming force analysis show that the stress from different parts of the size is different, but are both to the compression of tension, the axial compression. Compression of the radial and circumferential tension. The figure 3 shows, under the action of thrust P billet in the process of forming gradually expanding, bending, the bending resistance and abdominal P, is greater than that of the back drag and expansion drive is the synthesis result of the bending resistance and hole enlargement force Q (JV),The direction should be from the abdomen to the back direction, that is to say, the expansion tension of the abdomen is greater than the back diameter expanding force and bending Angle. Under certain conditions, the diameter expansion, bending, length difference, axial compression and circumferential expansion of the abdomen during the entire deformation process are achieved, but the thickness is basically unchanged, so the wall thickness is uniform.
3. Nondestructive testing of titanium welding parts
Titanium welding parts adopt X-ray inspection and ultrasonic inspection. X-ray inspection is in accordance with JIS Z 3107 standard for the quality and quality of weld cracks
Quantity, satisfied the demand of the user.
The product has been used in chemical industry, gas alkali industry, petrochemical industry and synthetic fiber industry.
