Lub rooj vag li qub tuaj yeem raug cais raws li qhov kev teeb tsa ntawm lawv qhov chaw sib khi rau hauv npoo - hom rooj vag li qub thiab sib npaug - hom rooj vag li qub. Nplhaib- hom rooj vag li qub tau muab faib ua ib zaug -disc, ob npaug-disc, thiab hloov pauv tau-disc hom, thaum sib npaug- hom rooj vag li qub tau muab faib ua ib zaug -disc thiab ob -disc hom. Raws li txoj hauj lwm ntawm cov qia threads, lawv raug cais raws li nce - qia los yog tsis - nce - qia rooj vag li qub.
Raws li txoj kev sib txuas, lawv tau muab faib ua flanged, threaded, taub qab-weld, qhov (socket)-weld, bellows- kaw, thiab siab- foob forged steel rooj vag li qub. Raws li kev ua haujlwm tshwj xeeb, lawv suav nrog cov hauv qab- kaw, tsho (tsim hluav taws xob), thiab mos- rooj vag li qub. Raws li kev khiav hauj lwm nruab nrab, lawv tau muab faib ua hom haum rau ammonia, natural gas, chav, dej, thiab lwm yam gases.