There are several grades under specification API 5CT, which covers casing and tubing specifically for the petrochemical and oil & natural gas industries. These grades are organized into three groups as follows -
Being an atypical grade, API 5CT H-40 pipes have a relatively lower yield strength and is not commonly used. Hence, many suppliers do not stock this product. On the other hand grade API 5CTQ K-55 is similar to grade J55 with regards to both its chemistry and yield strength, with the exception of its ultimate tensile strength, which is higher than grade J55. Since old grade API 5CTQ N-80 is susceptible to hydrogen sulfide induced stress related corrosion cracking, its use is limited to sweet oil and gas wells. There are two types under grade C90 i.e. - type 1 and 2. Type 1 under grade API 5CT C-90 is well suited for applications in sour service. Similar to grade C90, grade T-95 is separated into two types and can be used for sour wells. Although API 5CT T-95 is resistant to stress related corrosion cracking, but it is not resistant weight-loss. The use of API 5CT P-110 is in high pressured environments, particularly in deep sweet oil and gas wells. Just like grade H40, API 5CT Q-125 pipes are made to order, with preference given to the chemistry of type 1.
Outer diameter | Casing: OD 4 1/2"- 20" (114.3mm-508mm) Tubing: OD 2 3/8" - 4 1/2" (60.3mm-114.30mm) |
Wall Thickness | 0. 205"- 0.635" |
Length | R1:5.49-6.71m ;R2: 8.23-9.14m ;R3: 11.58-13.72m |
Connection | Casing: LTC, STC, BTC, VAM.Tubing: NUE, EUE |
End | Beveled, Square cut. And pipe protection cap specially for casing and tubing |
Surface | Corrosion proofing water based paint |
Heat treatment | Normalized, Quencher+Temper |
Carbon | Silicon | Manganese | Phosphorous | Sulphur | Molybdenum | Nickel | Chromium | Copper | Others |
– | – | – | 0.03 | 0.03 | – | – | – | – | – |
Yield Strength | Tensile Strength | Elongation A5 min | |||
MPa min | ksi min | MPa min | MPa min | ksi min | Percentage |
414 | – | 60 | – |