types of pipes
| seamless | |
|
HFS |
hot finished seamless |
| CDS |
cold drawn seamless |
|
longitudinally welded |
|
| ERW | electric resistant welded |
| HFI | high frequency induction |
| LSAW | submerged arc welded under protection atmosphere |
| spirally welded | |
|
HSAW |
submerged arc welded under protection atmosphere |