In China market, there are 3 types of corrugated steel pipe. Some is studied from other country, some is designed by Chinese corrugated steel pipe manufactures. Like the integrate corrugated steel pipe, it is special and only can be founded in China, helical corrugated steel pipe and assembled type corrugated steel pipe are studied from other countries
Integrate corrugated steel pipe produce process
The cheapest corrugated steel pipe is integrate type corrugated steel pipe. It is simple to produce, firstly we need a rolling machine, the rolling machine. It is a small machine, we feed the plain steel plate in the rolling machine, then the rolling machine will make sure the diameter of the culvert. After that, welding the edge of the steel plate to be a pipe. After this we put the steel pipe in to the corrugation machine, this machine with difference corrugation size wheels, the pipe will rolling on this machine too, and the corrugation will be generated. Difference corrugation adopt difference wheels. Finally, we welding flange on the both end of the corrugated steel pipe. Each ring is one section, install the culvert section by section, easy to assemble.
Helical corrugated steel pipe producing process
We imported a production line from Canada special for producing helical corrugated steel pipe. After producing, it is also in pipe shape, but it is difference to the integrate corrugated steel pipe. We feeding the coil steel to the production line, the coil steel will be winded spirally by the production line, at same time, it rolling the corrugation size. Sure, there are difference mould for the difference corrugation, just choose the right mould before producing the pipe is OK. And each spiral ring is locked by the bending edge. After finish producing, it will be cut as per the requested length.
Then we come to the second step, rolling the both ends of the spiral corrugated steel pipe, make the corrugation on the end of the pipe to be vertical to the ground, then it will not in helical shape, this is for connection sections. This corrugated steel pipe is connected by couplers, the coupler is also a corrugated pipe shape, but its corrugation is not helical, so we have to make the both end of the spiral corrugated steel pipe to be not helical. Then we can connect section by section by the couplers.
Riveted corrugated steel pipe manufacture process
Riveted corrugated steel pipe produce need a big investment to purchase production lines. Difference corrugation need difference production lines. Sure, some factory can change the corrugation mould on same production line when they want to produce difference corrugation size on one production line, but it will take days to changing mould, and need days to adjust machine, then it can not guarantee the producing time.
The riveted corrugated steel pipe is only can be a pipe shape after assembling, before assemble, it is only pieces of corrugated steel structure plate. Firstly we need to feed the coil steel or steel sheet in to the production line to roll the corrugation on the plain steel sheet. And it will be cut as per our designed length. Then we drilling or punching holes on the corrugated steel plate. Next step is rolling radius for each corrugated steel plate, then the corrugated steel structure plate is complete. When installation, just riveted each corrugated structure plate together to be a pipe shape.