CRA (Corrosion resistant alloy) clad pipe and lined pipe applied for the anti-corrosion environment, they have been considered as a new material in the oil and gas pipeline systems. Since they are two kinds of steel material that composite together through bonding processes. (Inner pipe material with expensive stainless or alloy steel, which we called CRA layer. Outer pipe with carbon steel pipe that standards in API 5L or ASTM A106/A53 etc.)
CRA clad pipe and lined pipe application
CRA clad and lined pipe generally used in petroleum industries for special working conditions. For on shore and off shore pipeline systems, there are often contain the high S, H2S, and CO2 chemicals in the transportation fluids. When these values reached a certain content it will make a big corrosion to the pipelines in Carbon and Manganum steel material like API 5L pipes and ASTM A106 pipes. In this case, the CRA clad and lined pipe is applied for this.
Why CRA pipe gets so popular
CRA material combined with carbon steel material, it is a great achievement for both the mechanical strength (Tensile and Yield strength), meanwhile to have the excellent corrosion resistance performances. No matter on the pipe personality or to save in economic purposes, clad and lined pipe is a perfect choice.
Then what is the manufacturing processes for CRA pipe?
There are two ways to mix CRA layer on the steel pipe, one is cladding, another one is lining.
Clad pipe manufacturing process
The point of manufacturing of clad pipe is using metallurgical ways to create the bond. Clad pipe adopts hot rolled or explosive clad plate to combined with carbon steel plate. (There are also other ways to bonding two kinds steel material, like weld overlay, or co-extrusion.)
After we get the CRA clad steel plates, then we begin the process for manufacturing plate to cladding pipe (An sample type):
Clad Steel Plate Checking – UT for Steel plate – Plate Beveling – Preforming – Forming to Pipe (JCOE) – Welding – Rounding – Hydrastatic test – Beveling pipe end – X Ray Test- Ultrasonic Test – Size Inspection and Measuring – Marking – Packing and Storage
Lined pipe manufacturing methods
For lined pipe is to create through a mechanical bond on the carbon steel pipe. (Put CRA pipe internal to connect to external C-Mn steel pipe through mechanical procedures)
Here is one way to manufacture the CRA lined pipe:
Outer Pipe (Backing Steel Pipe) Inspection – Cutting – Machining Backing Steel Pipe – Cleaning Inner Surface – Assembling Inner Alloy Pipe – Hydro forming – Cutting Lined Pipe Ends – Beveling – Welding – Sizing pipe End – Forming – RT – ET & Endoscope – Ultrasonic Test – PT – Measuring Size and Inspection – Marking – Packing
Another bonding process of CRA lined pipe is to use a Full-Length Pipe Expander than to use Hydroforming machine. (Between two options a Full-Length-Pipe-Expander is better for bonding CRA material for lined pipe)
Octal supplied CRA clad pipe and lined pipe in below specification
Outer Diameter Cladding pipe: 6” to 60”
OD range for CRA lined pipe: 2” to 24”
Thickness: Up to 80 mm (Clad pipe), 7 mm to 35 mm (For lined pipe)
Maximum length: 12.3 meter
Backing steel pipe (mother pipe) material: Carbon Steel Pipe, C-Mn Steel Pipe, API 5L line pipe, and Mineral Slurry steel pipe etc.
Cladding and Lining CRA (Corrosion resistant alloy) material: Austenitic stainless steel, nickel alloy steel, Hastelloy C276, titanium alloy steel duplex steel, and etc.
More over, We are also capable to supply clad pipe fittings.
CRA Lined Pipe Order Description & Specification
Line Pipe, Seamless, Carbon Steel Material, Outer Diameter 16 in, Nominal Weight 62.58 lb/ft, Wall thickness Schedule STD.
Standard and Grade ASTM A106 B, Ends Design Beveled, Inner Coating Lining HASTELLOY C276 in Thickness 0.125 in, External Coating Varnished, Nominal Length 12 Meter (40 FT)
Sample Description for Cladding Pipe Fittings Order
Eccentric Reducing, Material Carbon Steel, Standard and Grade ASTM A234 WPB, Ends Design Beveled.
Nominal Diameter 18 in x 16 in, Wall Thickness Sch 40. ASME B16.9 manufacturing standard, External Paint Anti-Corrosion Coating, Internal Coating Cladding 1/8” thick B575 N10276.