(1) Ngethuba lenkqubo yokukhupha, ubushushu bomgca wombhobho wensimbi ojikelezayo buqhubeka nokunyuka njengoko inkqubo yokukhupha iqhubeka. Ekupheleni kwe-extrusion, iqondo lokushisa kwindawo yodonga lwangaphakathi lwe-lining kufuphi ne-extrusion die liphezulu, lifikelela kwi-631 ° C. Ubushushu be-lining ephakathi kunye ne-cylinder yangaphandle ayitshintshi kakhulu.

(2) Kwimeko engasebenziyo, ubuninzi boxinzelelo olulinganayo lombhobho wensimbi ojikelezayo yi-243MPa, eyona nto igxininiswe kudonga lwangaphakathi lombhobho ojikelezayo. Kwimeko yokufudumala, ixabiso layo eliphezulu liyi-286MPa, ihanjiswe phakathi kwendawo yangaphakathi yodonga lwe-lining. Ngaphantsi kweemeko zokusebenza, uxinzelelo lwayo olulinganayo oluphezulu luyi-952MPa, olusasazwa kakhulu kwindawo yobushushu obuphezulu kwindawo ephezulu yodonga lwangaphakathi. Indawo yoxinzelelo lwexinzelelo ngaphakathi kwipayipi yensimbi ye-spiral isasazwa kakhulu kwindawo yobushushu obuphezulu, kwaye ukuhanjiswa kwayo ngokusisiseko kuyafana nokuhanjiswa kweqondo lokushisa. Uxinzelelo lwe-thermal olubangelwa ukuhluka kweqondo lokushisa lunempembelelo enkulu ekuhanjisweni koxinzelelo lwangaphakathi lombhobho wensimbi ojikelezayo.

(3) Uxinzelelo lwe-radial kumbhobho wensimbi ojikelezayo. Kwimeko engasebenziyo, ipayipi yensimbi ye-spiral ichaphazeleka kakhulu yi-prestress enikezelwa yi-prestress yangaphandle. Umbhobho wensimbi ojikelezayo ukwimeko yoxinzelelo olucinezelayo kwicala le-radial. Elona xabiso likhulu yi-113MPa, esasazwa kudonga lwangaphandle lombhobho wensimbi ojikelezayo. Kwimeko yokufudumala, uxinzelelo lwalo oluphezulu lwe-radial luyi-124MPa, lugxininiswe ngokukodwa kubuso obuphezulu kunye nezantsi. Kwimeko yokusebenza, uxinzelelo lwalo oluphezulu lwe-radial luyi-337MPa, olugxininiswe kakhulu kwindawo ephezulu ye-spiral steel pipe.