UNS S31603 Capillary Coiled Tubing Thermoplastic Encapsulation Material

UNS S31603 Encapsulated Control Line Stainless Steel Polished Surface

UNS S31603, Chemical composition

Application: Standard oil and gas CRA (corrosion resistant alloy)

Tensile strength, min.: 70ksi (485MPa)

Yield strength, min.: 25ksi (170MPa)

Elongation in 2 in., min.: 35%

Description

S31603 is a chromium-nickel austenitic stainless steel with an addition of molybdenum and reduced carbon content. The addition of molybdenum provides improved resistance to pitting and crevice corrosion in environments containing halides such as chlorides when compared to so-called conventional 18 chromium 8 nickel austenitic stainless steels such as S30403. The reduced carbon content minimizes harmful chromium carbide precipitation during welding and thereby improves resistance to intergranular corrosion. Austenitic stainless steels such as S31603 are susceptible to stress corrosion cracking (SCC) in environments containing chlorides and other halides. S31603 is generally used in oil and gas production environments which do not contain oxygen and have limited amounts of chlorides and hydrogen sulfide. Consult ISO 15156-3, Table A.2 for the limits regarding S31603 in hydrogen sulfide-containing environments for oil and gas production.

HYDRAULIC CONTROL LINE APPLICATIONS

STAINLESS STEEL AND HIGH NICKEL ALLOYS COILED TUBING SOLUTIONS

MEILONG is an important manufacturer in premium coiled seamless & welded tubular solutions for oil and gas applications. In an endeavor to increase its presence in subsea, MEILONG has extended its offer by developing a highly innovative tubular solution for umbilical projects.

MEILONG has developed a strong and unique expertise in premium quality tubes to answer the most stringent specifications of its customers. Based on this expertise in high pressure, and extremely high pressure tubes, MEILONG’s state-of-art factory is exclusively dedicated to the manufacturing and supply of super duplex and high nickel alloys tubes for corrosive downhole applications and is now ready to offer the highest specifications for your toughest challenges.

High quality polymeric jackets/encapsulations provide added protection

Core tubing is evaporated with the latest thermoplastic elastomeric compounds designed to outlast the life of most project tubing installations by reducing the possibility of corrosion and mechanical damage. They can stand up to a wide range of chemical inhibitors and seawater. Most jackets are manufactured from fire retardant, all-weather, abrasion-resistant compound, designed to remain strong and flexible through wide ranges of temperatures and pressures.

PVC

PP (polypropylene)

SP (Santoprene)

F46 (FEP)

Nylon

Corrosion Resistance

● Organic acids at high concentrations and moderate temperatures

● Inorganic acids, e.g. phosphoric and sulphuric acids, at moderate concentrations and temperatures. The steel can also be used in sulphuric acid of concentrations above 90% at low temperature.

● Salt solutions, e.g. sulphates, sulphides and sulphites

● Caustic environments

Austenitic steels are susceptible to stress corrosion cracking. This may occur at temperatures above about 60°C (140°F) if the steel is subjected to tensile stresses and at the same time comes into contact with certain solutions, particularly those containing chlorides. Such service conditions should therefore be avoided. Conditions when plants are shut down must also be considered, as the condensates which are then formed can develop conditions that lead to both stress corrosion cracking and pitting.

S31603 has a low carbon content and therefore better resistance to intergranular corrosion than steels of type TP316.

Standards and Specifications

ASTM A269, Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubing for General Service

Meets the material limits for S31603 austenitic stainless steel listed in ISO 15156-3, Table A.2

Production Process

Welded & Redrawn Tubing

Strip splice welds join lengths of cold rolled strip to enable long lengths between orbital welds (greater than 14,500 ft between orbital welds is achievable). The strip is formed into a tubular cross section and longitudinally seam welded using the gas tungsten arc (GTAW) process. The tubing is first sunk to an intermediate outside diameter, heat treated, and make the same process to obtain the desired size.

Seamless & Redrawn Tubing

Seamless extruded tube hollows are drawn or drawn / sunk to final size to produce seamless tubing coils 500 to 2,000 ft. long, depending upon the size. The tubing is heat treated and joined by orbital welding to achieve the desired length. The final material condition of the tubing is heat treated.

Standards and Specifications

Tubing Specification PTM-TS-011, Duplex Stainless 2205 Tubing for Control Line Applications

ASTM A789, Standard Specification for Seamless and Welded Ferritic/Austenitic Stainless Steel Tubing for General Service

Quality Assurance

Eddy current test (ECT)

Ultrasonic test

Hydrostatic test

Chemical composition analysis

Tensile test

Hardness test

Dimension & visual inspect

Metallographic analysis

Coiled Encapsulated Tubing (Bare Tubing Size)

Tubing length up to 32,808 feet (10,000 m)

For control line, chemical injection line, umbilicals

Available materials

Austenitic: 316L

Duplex: S31803, S32205

Super Duplex: S32750

Nickel alloy: N06625, N08825

Norm Equivalence