Ishubhu elingenamthungo lenziwe ngamabhulokhi ensimbi aqinile ngaphandle kokushisela. Ama-welds angase amele izindawo ezibuthakathaka (ezingenwa ukugqwala, ukugqwala kanye nokulimala okuvamile).

Uma kuqhathaniswa namashubhu ashiselwe, amashubhu angenamthungo anomumo obikezelwayo futhi onembe kakhudlwana ngokuya ngokuyindilinga kanye ne-ovality.

Ububi obuyinhloko bamapayipi angenamthungo ukuthi izindleko ngethani ziphakeme kunamapayipi e-ERW anosayizi nebanga elifanayo.

Isikhathi sokuhola singase sibe side ngoba kunabakhiqizi abambalwa bamapayipi angenamthungo kunamapayipi ashiselwe (uma kuqhathaniswa namapayipi angenamthungo, umgoqo wokungena wamapayipi ashiselwe uphansi).

Ukuqina kodonga lweshubhu engenamthungo kungase kungahambisani nobude bayo bonke, empeleni ukubekezelelana okuphelele kungu- +/- 12.5%.