In general, these kind of pipes are produced in the spiral form and inside of the profile of the pipe is reinforced and filled up with the pipe which in Iran is called core-tube pipes. Core-tube has higher melting temperature compared to PE which make possibility to shape the profile. In this kind of pipe, it’s possible to produce in several steps and layers which makes the range of production wider than other kind of pipes.
The Core-tube is produced separately so it can be used in Profiled pipe production machine. This Core-tube is used inside the Profiled pipe so sunlight has no effect on it. As a result there is no need to use Anti-UV or masterbatch which is contains Anti-UV. So, mostly it produced in white color for this purpose. The shape and type of production of core-tube is similar to corrugated pipes. The only difference is that core-tube does not have inside layer and the raw material which is used in this production process is PP (Polypropylene).
With considering that profiled pipes are used for the projects with pipe diameter of 1200mm or bigger, for maintenance and inspection of the pipes there is a possibility to go to inside and there is no need to produce inside layer with lighter color. So, inside color is produced in black.
Static calculation for defining the suitable pipe has significant impact on project costs in the projects with big diameter pipes and it can reduce it notably. According to the variety in the range of production of profiled pipe, there is a possibility to choose a suitable pipe for given backfilling and environmental conditions.
For connection of profile pipes there are some options such as:
Socket and spigot
As it mentioned in Corruspiral pipes, in this type of connection there are socket and spigot at the end of each pipes and the ring between is make the sealing.

PE wielding (Extruder wielding)
This connection by melting two end of the pipes and inserting the melted PE material after cooling down makes this connection happen. This process makes the connection area reach to same strength of the rest of the pipe and ensure sealing in that point.

Electrofusion wielding
In fact, the main concept in this connection is depend on melting the area between socket and spigot of the pipe by the current in the wire which is placed in socket of the pipe including pressure surrounding the socket which make the connection happen.