A na-ekewa ọkpọkọ ígwè n'ime ọkpọkọ nchara na-enweghị ntụpọ na ọkpọkọ ígwè welded (paịpụ seamed).

Ọkpụkpụ tube bụ ụdị tube enweghị nkebi. Usoro mmepụta ihe bụ otu ihe ahụ nke ọkpọkọ na-enweghị ntụpọ, ma e nwere ihe siri ike chọrọ na akara nchara eji eme ihe maka ịmepụta ọkpọkọ ígwè. Dị ka ojiji okpomọkụ si dị, ọ nwere ike kewaa n'ime izugbe boilers tubes na elu-nrụgide ji esi mmiri ọkụ tubes.

1) The ígwè akara ule nke elu-edu carbon structural ígwè bụ 20G, 20MnG na 25MnG.

2) Alloy structural ígwè akara ule 15MoG, 20MoG, 12CrMoG, 15CrMoG, 12Cr2MoG, 12CrMoVG, 12Cr3MoVSiTiB, wdg.

Ọkpụkpụ ígwè na-enweghị nkebi maka ndị na-esi mmiri nrụgide dị ala na nke ọkara (GB3087-2008), tubes ígwè na-enweghị nkebi maka ndị na-esi mmiri nrụgide dị elu (GB5310-2008), ASME SA-106, ASME SA-213, ASTM A335

Ke adianade do, anyị ụlọ ọrụ na-arụ ọrụ enweghị nkebi ígwè ọkpọkọ maka owuwu (GB/T 81628163), ọkpọkọ igwe anaghị agba nchara maka mgbawa mmanụ ala (GB9948), ọkpọkọ ígwè enweghị nkebi maka fatịlaịza nrụgide dị elu (GB6479), ọkpọkọ ọkpọkọ mmanụ (API 5L) na ọkpọkọ mkpuchi mmanụ (API 5CT), na ihe nrụnye ọkpọkọ.