TPWJ, 2020, #11, 12-17 pages
Quality and operational characteristics of welded joints of pipes of different-type polyethylenes
M.O. Kovalchuk, M.V. Iurzhenko, V.L. Demchenko, M.G. Korab and R.V. Kolisnyk
E.O. Paton Electric Welding Institute of the NAS of Ukraine
11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine. E-mail: firstname.lastname@example.org
Polyethylene raw materials used for production of polyethylene pipes are constantly being improved. At the beginning
of the construction of plastic pipelines, the so-called low pressure polyethylene, currently known as PE-63 grade was
used. Subsequently, new, more advanced types of raw materials, which represent a copolymer of polyethylene with
hexane, were developed. Today, almost all pressure pipes are made of PE-80 and PE-100 grades of polyethylenes.
However, during the repair and reconstruction of plastic pipelines, there is an urgent problem of joining pipes of PE-63,
which have been operated for a long time, with new pipes made of polyethylenes of grades PE-80 and PE-100. In the
paper, complex investigations of thermophysical properties of technical polyethylenes were carried out and significant
differences were revealed, which should be taken into account during the repair of polymer pipelines. Experimental
welding of pipe specimens from both single- as well as different-type polyethylenes was carried out. Morphological
and mechanical studies of welded joints of polyethylene pipes of grades PE-63, PE-80, and PE-100 were performed.
According to the results of investigations, the influence of their thermophysical properties and parameters of the welding
process on the morphological structure and quality of welded joints of different-type polyethylenes was determined.
Mathematical modeling of temperature fields during butt welding was carried out. A two-zone heating tool for butt
welding of pipes with an outer diameter of up to 110 mm of different-type polyethylenes of pipe grades PE-63 and
PE-80, PE-100 using a heated tool was designed and created. In order to test an experimental specimen of a two-zone
heating tool, a series of experiments were carried out, which showed an improvement in the strength characteristics of
the produced welded joints. 8 Ref., 4 Tables, 10 Figures.
polyethylene raw material of different types, polyethylene pipes, welded joints
1. Kimelblat, V.I., Volkov, I.V., Glukhov, V.V. (2020) Optimization
of resistance butt welding. Accounting for the properties
of polymers. Polimernye Truby, 28(2), 32–36 [in Russian].
2. Komarov, G.V. (2015) Composition and properties of polymer
materials affecting their weldability. Polimernye Materialy,
9, 44‒48 [in Russian].
3. GOST 16338‒85: Low-pressure polyethylene. Specifications
4. GOST R 50838–95: Polyethylene pipes for gas pipelines.
Specifications [in Russian].
5. DSTU B V. 2.7-73–98: Polyethylene pipes for the supply of
gaseous fuel. Specifications [in Ukrainian].
6. DSTU B V.2.7-151:2008: Polyethylene pipes for the supply of
cold water. Specifications [in Ukrainian].
7. DBN V. 2.5–41:2009: Gas pipelines from polyethylene pipes.
Design. Construction [in Ukrainian].
8. DSTU EN12814–2:2018: Testing of welded joints of thermoplastics
semi-finished products. Pt 2: Tensile test [in
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