2. Nruab nrab taub welded Yeeb Nkab Chav

The mid-diameter welded pipe unit (8-26in) was the first to use the counter-roll forming method, but since the emergence of the row forming method in the 70s of the 20th century, the row roll forming method has become the mainstream of the medium-diameter welded pipe unit. Tom qab lub 90s, tsuas yog rau 5 lub teeb ntawm 12IN units tshiab khiv ua los ntawm Taiwan Geng'an cov tuam txhab muab kev zam rau kev txwv yob txoj kev yob txoj kev.
Muaj peb cov txheej txheem tseem ceeb rau cov kab yob sib sau txoj kev ntawm cov qauv yeeb nkab welded, ib nrab kab roll txoj kev thiab ncaj flange kab yob txoj kev sib. Nws cov tuam ntxhab tsuas yog suav nrog DMS hauv Fabkis, vai hauv Austria thiab SMS- Cov Erw nyob hauv ntiaj teb nyob rau hauv tsib lub tuam txhab tau tsim los ntawm peb lub tuam txhab no. Cov ntau yam tseem ua los ntawm cov chav nyob no yog kab kav dej, kav dej thiab cov teeb meem.