Steel
Helically corrugated metal pipes and coupling band joints are made of galvanized rolled steel sheets min. strength class 256 as per GOST 19281, GOST 1050 or GOST R 52246. Applicable grades:
- S275 as per GOST 19281, EN 10025, properties: min. yield strength 275 MPa, min. tensile strength 330 MPa;
- S280 as per GOST 52246, EN 10346, properties: min. yield strength 280 MPa, min. tensile strength 360 MPa;
Mechanical properties of HCMP steel
| Technical | Grade | |
|---|---|---|
| specifications | S275 | S280 |
| Reference | PN-EN 10025 | PN-EN 10346 |
| Yield point
Re [MPa] |
275 | 280 |
| Tensile strength
Rm [MPa] |
330 | 360 |
| Elongation
A80min [%] |
21 | 18 |
** Steel sheets are delivered from vendors as pre-coated coils as per the standards above:
The principal coating types applied at vendor factories onto rolled steel for helically corrugated metal pipes are:
- bilateral hot-dip galvanizing zinc coating as per GOST 9.307 (ISO 1461), GOST R 52246, min. weight 720 g / m2,min. thickness 48/50 um;
- high-density (low-pressure) polyethylene (HDPE), min. thickness 300 um, hot-laminated onto zinc coating at one/both sides.
