API specification 5CT is a technical standard for tubes and pipes in a system intended for use in oil wells in petroleum as well as in natural gas industries. Unlike API 5L, the API 5CT Grade L80 Pipes are classified into three product specification levels, i.e. - PSL-1, PSL-2, and PSL-3. Pipes that belong to grade L80 are heat treated after being upset. Per this standard, different grades will vary in their heat treatment processes.
For instance, api 5ct grade l80 type 1 Casing and Tubing must not be tempered at temperatures below 1150°F to avoid becoming brittle. Moreover, grade L80 pipes are not recommended to be cold worked after heat treatment. For an API 5CT Casing tube that has been oil quenched, a modification can be done with regards to increasing the content of carbon. One of the major benefits of using the API 5CT Casing and Tubing for the petroleum industry is because the steel alloy used can withstand corrosion from bi-products such as carbon dioxide in addition to hydrogen sulfide. Hydrogen sulfide causes tremendous stress on pipes, especially if they are welded. However, the use of seamless steel API 5CT GRADE L80 Pipes is much more resilient and can last longer as they aren’t susceptible to cracking. Under this specification, the standard API 5CT L-80 Casing Pipe does not contain sulfur and is a non-corrosive component.
Grade | C≤ | Si≤ | Mn≤ | P≤ | S≤ | Cr≤ | Ni≤ | Cu≤ | Als≤ |
API 5CT L80 | 0.15-0.22 | 1.00 | 0.25-1.00 | 0.020 | 0.010 | 12.0-14.0 | 0.20 | 0.20 | 0.020 |
Steel Grade | Yield Strength (Mpa) | Tensile Strength (Mpa) |
API 5CT L80 | 552-655 | ≥655 |
Types of steel tubes | Outer Diameter | Wall Thickness | |
Cold-rolled tubes | Tube sizes(mm) | Tolerances(mm) | Tolerances(mm) |
<114.3 | ±0.79 | -12.5% |
Size | Weight | Outside Diameter | Wall Thickness | End Finish | ||||||
Grade | ||||||||||
in | mm | in | mm | J55K55 | L80 | N80 | C90T95 | P110 | ||
4 1/2 | 9.50 | 4.500 | 114.3 | 0.205 | 5.21 | PS | – | – | – | – |
10.50 | 0.224 | 5.69 | PSB | – | – | – | – | |||
11.60 | 0.250 | 6.35 | PSLB | PLB | PLB | PLB | PLB | |||
13.50 | 0.290 | 7.37 | – | PLB | PLB | PLB | PLB | |||
15.10 | 0.337 | 9.56 | – | – | – | – | PLB | |||
5 | 11.50 | 5.00 | 127.00 | 0.220 | 5.59 | PS | – | – | – | – |
13.00 | 0.253 | 6.43 | PSLB | – | – | – | – | |||
15.00 | 0.296 | 7.52 | PSLB | PLB | PLB | PLBE | PLB | |||
18.00 | 0.362 | 9.19 | – | PLB | PLB | PLBE | PLB | |||
21.40 | 0.437 | 11.10 | – | PLB | PLB | PLB | PLB | |||
23.20 | 0.478 | 12.14 | – | PLB | ||||||
24.10 | 0.500 | 12.70 | – | PLB | ||||||
5 1/2 | 14.00 | 5.500 | 139.7 | 0.244 | 6.20 | PS | – | – | – | – |
15.50 | 0.275 | 6.98 | PSLB | – | – | – | – | |||
17.00 | 0.304 | 7.72 | PSLB | PLB | PLB | PLBE | PLB | |||
20.00 | 0.361 | 9.17 | – | PLB | PLB | PLBE | PLB | |||
23.00 | 0.415 | 10.54 | – | PLB | PLB | PLBE | PLB | |||
6 5/8 | 20.00 | 6.625 | 168.28 | 0.288 | 7.32 | PSLB | – | – | – | – |
24.00 | 0.352 | 8.94 | PSLB | PLB | PLB | PLBE | PLB | |||
28.00 | 0.417 | 10.59 | – | PLB | PLB | PLBE | PLB | |||
32.00 | 0.475 | 12.06 | – | PLB | PLB | PLBE | PLB | |||
7 | 17.00 | 7.00 | 177.80 | 0.231 | 5.87 | – | – | – | – | – |
20.00 | 0.272 | 6.91 | PS | – | – | – | – | |||
23.00 | 0.317 | 8.05 | PSLB | PLB | PLB | PLBE | – | |||
26.00 | 0.362 | 9.19 | PSLB | PLB | PLB | PLBE | PLB | |||
29.00 | 0.408 | 10.36 | – | PLB | PLB | PLBE | PLB | |||
32.00 | 0.453 | 11.51 | – | PLB | PLB | PLBE | PLB | |||
35.00 | 0.498 | 12.65 | – | PLB | PLB | PLBE | PLB | |||
38.00 | 0.540 | 13.72 | – | PLB | PLB | PLBE | PLB | |||
7 5/8 | 24.00 | 7.625 | 193.68 | 0.300 | 7.62 | – | – | – | – | – |
26.40 | 0.328 | 8.33 | PSLB | PLB | PLB | PLBE | PLB | |||
29.70 | 0.375 | 9.52 | – | PLB | PLB | PLBE | PLB | |||
33.70 | 0.430 | 10.92 | – | PLB | PLB | PLBE | PLB | |||
39.00 | 0.500 | 12.70 | – | PLB | PLB | PLBE | PLB | |||
42.80 | 0.562 | 14.27 | – | PLB | PLB | PLB | PLB | |||
45.30 | 0.595 | 15.11 | – | PLB | PLB | PLB | PLB | |||
47.10 | 0.625 | 15.88 | – | PLB | PLB | PLB | PLB | |||
8 5/8 | 24.00 | 8.625 | 219.08 | 0.264 | 6.71 | PS | – | – | – | – |
28.00 | 0.304 | 7.72 | – | – | – | – | – | |||
32.00 | 0.352 | 8.94 | PSLB | – | – | – | – | |||
36.00 | 0.400 | 10.16 | PSLB | PLB | PLB | PLBE | PLB | |||
40.00 | 0.450 | 11.43 | – | PLB | PLB | PLBE | PLB | |||
44.00 | 0.500 | 12.70 | – | PLB | PLB | PLBE | PLB | |||
49.00 | 0.557 | 14.15 | – | PLB | PLB | PLBE | PLB | |||
9 5/8 | 32.30 | 9.625 | 244.48 | 0.312 | 7.92 | – | – | – | – | – |
36.00 | 0.352 | 8.94 | PSLB | – | – | – | – | |||
40.00 | 0.395 | 10.03 | PSLB | PLB | PLB | PLBE | – | |||
43.50 | 0.435 | 11.05 | – | PLB | PLB | PLBE | PLB | |||
47.00 | 0.472 | 11.99 | – | PLB | PLB | PLBE | PLB | |||
53.50 | 0.545 | 13.84 | – | PLB | PLB | PLBE | PLB | |||
58.40 | 0.595 | 15.11 | – | PLB | PLB | PLB | PLB | |||
10 3/4 | 32.75 | 10.75 | 273.05 | 0.279 | 7.09 | – | – | – | – | – |
40.50 | 0.350 | 8.89 | PSB | – | – | – | – | |||
15.50 | 0.400 | 10.16 | PSB | – | – | – | – | |||
51.00 | 0.450 | 11.43 | PSB | PSB | PSB | PSBE | PSB | |||
55.50 | 0.495 | 12.57 | – | PSB | PSB | PSBE | PSB | |||
60.70 | 0.545 | 13.84 | – | – | – | PSBE | PSB | |||
65.70 | 0.595 | 15.11 | – | – | – | PSB | PSB | |||
13 3/8 | 48.00 | 13.375 | 339.73 | 0.330 | 8.38 | – | – | – | – | – |
54.50 | 0.380 | 9.65 | PSB | – | – | – | – | |||
61.00 | 0.430 | 10.92 | PSB | – | – | – | – | |||
68.00 | 0.480 | 12.19 | PSB | PSB | PSB | PSB | PSB | |||
72.00 | 0.514 | 13.06 | – | PSB | PSB | PSB | PSB | |||
16 | 65.00 | 16 | 406.40 | 0.375 | 9.53 | – | – | – | – | – |
75.00 | 0.438 | 11.13 | PSB | – | – | – | – | |||
84.00 | 0.495 | 12.57 | PSB | – | – | – | – | |||
109.00 | 0.656 | 16.66 | P | P | P | – | P | |||
18 5/8 | 87.50 | 18.625 | 473.08 | 0.435 | 11.05 | PSB | – | – | – | – |
20 | 94.00 | 20 | 508.00 | 0.438 | 11.13 | PSLB | – | – | – | – |
106.50 | 0.500 | 12.70 | PSLB | – | – | – | – | |||
133.00 | 0.635 | 16.13 | PSLB | – | – | – | – |