There are also many processing methods for pipe fittings. Many of them also belong to the category of machining, and the most commonly used are stamping, forging, roller processing, rolling, bulging, stretching, bending, and combined processing. Pipe processing is an organic combination of machining and metal pressure processing.
Here are some examples:
Forging method: use a forging machine to punch and stretch the end or part of the pipe to reduce the outer diameter, and the commonly used forging machines are rotary type, connecting rod type and roller type.
Stamping method: The tube end is expanded to the required size and shape with a taper core on the punch press.
Roller method: A core is placed in the tube, and the outer circumference is pushed with a roller for round edge processing.
Rolling method: generally no mandrel is used, suitable for the inner round edge of thick-walled pipes.
Bending forming method: there are three methods that are more commonly used, one method is called stretching method, the other method is called stamping method, and the third is the roller method that everyone is more familiar with, there are 3-4 rollers, two fixed rollers, one adjustment roller, adjust the fixed roller distance, and the finished pipe fittings are bent. This method is widely used, and the curvature can be increased if the spiral tube is produced.
Bulging method: one is to place rubber in the tube, and compress it with a punch above to make the tube protrude and form; Another method is hydraulic bulging forming, filling the middle of the pipe with liquid, and relying on liquid pressure to bulge the pipe into the desired shape, like most of the production of bellows we commonly use this method.
In short, pipe fittings are widely used and varied. Japanese production methods are all licensed, and some pipe fitting production methods and processes have been declared patents, and there are many pipe fitting patents, most of which are combined processing. There is a big gap in the processing of pipe fittings in China, for example: the three-way four-way for bicycles has been used in foreign countries as early as four or five years to use the bulging tube head, and China's manufacturers may still be using the welding method. People hardly recognize this kind of thing, it is difficult to accept new things, and even if there is, manufacturers are not necessarily willing to change this process. China has developed very slowly and backwardly in cast iron drainage pipes and other pipe fittings.
