Karkataccen bututu, wanda kuma aka sani da karkace karfe bututu ko karkace welded bututu, shi ne wani low-carbon tsarin karfe ko low-gawa tsarin karfe tsiri birgima a cikin wani tube blank a wani helical kwana (wanda ake kira forming kwana), kuma aka sani da karkace tube ko wani karkace jiki. Diamita na waje na bututun karkace yana da kusan nanometer 30, diamita na ciki kusan nanometer 10 ne, kuma farar da ke tsakanin spirals kusa da nanometer 11 ne.

Wadanne hanyoyi ne don gano ko ingancin manyan bututun welded mai girman diamita ya kai daidai?

1. Dubawa ta hanyar jiki: Hanyar duban jiki hanya ce ta aunawa ko dubawa ta hanyar amfani da wasu al'amura na zahiri.

2. Gwajin ƙarfi na jirgin ruwa: Baya ga gwajin matsewa, jirgin kuma yana buƙatar yin gwajin ƙarfi. Yawanci akwai nau'ikan gwajin hydrostatic iri biyu da gwajin karfin iska. Dukansu biyu suna duba matsewar walda a cikin tasoshin da bututun da ke aiki a ƙarƙashin matsin lamba. Gwajin hawan iska ya fi hankali da sauri fiye da gwajin hydraulic. A lokaci guda, babban diamita karkace welded bututu bayan gwajin ba ya bukatar a zubar, wanda ya dace musamman ga kayayyakin da wuya magudanun ruwa. Koyaya, haɗarin gwajin ya fi na gwajin hydrostatic girma. Yayin gwajin, dole ne a bi matakan fasaha masu dacewa don hana hatsarori yayin gwajin.
3. Gwajin Hydrostatic: Kowane babban diamita karkace mai waldadden bututu ya kamata a yi gwajin matsa lamba na hydrostatic ba tare da yabo ba. Ana ƙididdige gwajin gwajin kamar haka: P=2ST/D.
A cikin dabarar, S — gwajin danniya Mpa na gwajin hydrostatic, kuma an zaɓi danniya na gwajin hydrostatic bisa ga 60% na ƙimar yawan amfanin ƙasa da aka ƙayyade a daidaitaccen daidaitaccen tsiri na ƙarfe.

4. Yin hukunci daga saman, wato, duban bayyanar, hanya ce mai sauƙi da amfani da ita. Yana da muhimmin ɓangare na binciken da aka gama. Yafi nemo lahani a saman walda da rarrabuwa mai girma. Gabaɗaya, ana bincikar shi da idanu tsirara, tare da taimakon samfuri na yau da kullun, ma'auni, gilashin ƙara girma da sauran kayan aikin. Idan akwai lahani a saman walda, akwai yiwuwar lahani a cikin walda.