The disadvantages of pushing seamless elbow
In the process of construction, we find that the quality of pushing seamless elbow fitting has the following problems.
First, the wall thickness of the pipe fitting is uneven.
The uneven wall thickness of pushing seamless elbow pipe fitting mainly occurs in the parts with the most deformation. Such as the wall thickness of the back of the elbow is thicker than other parts;
Provisions in the relevant national standards. For this kind of problem inspection, with the general caliper and other measuring tools are often difficult to find, at this time only using ultrasonic thickness gauge can be measured.
Second, the hardness exceeded.
The problem of exceeding the hardness of push seamless elbow is mainly due to the problem of heat treatment after forming, and the solution is to use the correct heat treatment process to perform a heat treatment again.
Third, defects arising from raw materials and processes.
Pushing seamless elbow has the greatest safety hazard to the device. It's more troublesome to check. The factors that produce defects are more complicated, and they both have defects of the material itself and the defects of processing manufacturing process and incorrect heat treatment process.
Please see the production processing of pushing seamless elbow as below:
One of the most popular manufacturing method of Pipe Fitting elbows is mandrel method which is one type of hot forming methods.
In this method, the pipe is cut to pieces and pushed with the help of hydraulic stamping. The induction heating coil heats the pipe and pushes it onto a mold called a "mandrel" so that the pipe expands and bends at the same time. This method can be used to manufacture a wide range of elbow diameters.
From this production processing you can find why the pushing elbow has these disadvantages. Because during the production, the raw material need to be heated, and push which will lead the internals changed and the wall thickness of back of elbow reduced.