Common connection methods of 3PE anti-corrosion steel pipes and reasons for uneven anti-corrosion thickness

First, the reasons for uneven anti-corrosion thickness of 3PE anti-corrosion steel pipes.
The industry standard SY/T0413-2002 does not stipulate the uniformity of thickness, but only stipulates the minimum thickness value of the coating, but requires that the minimum thickness value of the coating cannot be lower than the thickness value of the low point, rather than the average value of multiple test points. If the coating thickness is uneven during the coating of 3PE anti-corrosion steel pipes, it will inevitably cause waste of butcher materials. This is because when the coating thickness of the thin part is guaranteed to meet the low standard, the thickness of the thick part will be greater than the thickness of the coating standard.
Moreover, uneven coating can easily cause the coating thickness of the thin part of the 3PE anti-corrosion steel pipe to fail to meet the standard. The main reasons for uneven thickness during the production process are uneven material discharge at several places and the bending of steel pipes.
An effective way to control the uneven coating of 3PE anti-corrosion pipelines is to adjust several extrusion dies to make the thickness of the anti-corrosion coating at several places as uniform as possible, and unqualified steel pipes are not put online for coating.

Second, common connection methods of 3PE anti-corrosion steel pipes.
(1) Welding connection: If there is basically no need to disassemble, welding can be used. Compared with the traditional connection method, this method has a simple structure, and any components can be directly connected; the material is economical and the cross-section is not weakened; the manufacturing and processing are convenient and can be automated; the connection is airtight and the structure is rigid. In terms of emergency repair efficiency, it is not suitable for today’s environment.
(2) Flange connection: The flange is welded to the pipe mouth. The connection between the two pipe mouths is first welded with flanges or threaded with flanges, and then the two welded flanges are connected, and a gasket is added in the middle.
(3) Grooved pipe fitting connection: This connection method is the main technology for the connection of liquid and gas pipelines. The pipe fittings required for this connection method are: rigid joints, flexible joints, mechanical tees and grooved flanges, elbows, tees, crosses, reducers, blind plates, etc.