UNS S31603 Encapsulated Control Line Stainless Steel Polished
Surface
UNS S31603, Chemical composition
| Element | Composition, % |
| Chromium | 16.0-18.0 |
| Nickel | 10.0-14.0 |
| Molybdenum | 2.0-3.0 |
| Manganese | 2.00 max. |
| Silicon | 1.00 max. |
| Carbon | 0.035 max. |
| Sulfur | 0.030 max. |
| Phosphorous | 0.045 max. |
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)
| Imperial size | Metric size |
OD inch | WT inch | OD mm | WT mm |
| 1/4 (0.250) | 0.035 | 6.35 | 0.89 |
| 0.049 | 6.35 | 1.24 |
| 0.065 | 6.35 | 1.65 |
| 0.083 | 6.35 | 2.11 |
| 3/8 (0.375) | 0.035 | 9.53 | 0.89 |
| 0.049 | 9.53 | 1.24 |
| 0.065 | 9.53 | 1.65 |
| 0.083 | 9.53 | 2.11 |
| 1/2 (0.500) | 0.035 | 12.7 | 0.89 |
| 0.049 | 12.7 | 1.24 |
| 0.065 | 12.7 | 1.65 |
| 0.083 | 12.7 | 2.11 |
| 5/8 (0.625) | 0.049 | 15.88 | 1.24 |
| 0.065 | 15.88 | 1.65 |
| 0.083 | 15.88 | 2.11 |
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
| Grade | UNS No | Euro norm | Japanese |
| No | Name | JIS |
| Alloy | ASTM/ASME | EN10216-5 | EN10216-5 | JIS G3463 |
| 316L | S31603 | 1.4404, 1.4435 | X2CrNiMo17-12-2 | SUS316LTB |
| 2205 | S31803 | 1.4462 | X2CrNiMoN22-5-3 | SUS329J3LTB |
| 2507 | S32750 | 1.4410 | X2CrNiMoN25-7-4 | |
| 625 | N06625 | 2.4856 | NiCr22Mo9Nb | |
| 825 | N08825 | 2.4858 | NiCr21Mo | |
