TPi November 2013

stainless steel tubes

Stainless steel products, single sourcing and advice

“Supplying advanced stainless steels and special alloys to manufacturers and process companies throughout South America, our technical specialists can also offer advice on tube applications right across the industrial spectrum,” said Angelo Martines, Sandvik tubular products sales manager, South America. “Whether the seamless tubes are for industrial heat exchangers, high temperature applications such as steel mills or the lime industry, or even special alloys and titanium for the aerospace industry, our specialists can assist.” Sandvik is using its capabilities to supply stainless steel tubing for hydraulic and instrumentation applications in the oil and gas industry, and helping to reduce the number of corrosion-related failures. Sandvik SAF 2507 TM is a Super Duplex (austenitic-ferritic) stainless steel designed for service in highly corrosive conditions. The material offers resistance to pitting corrosion and stress corrosion cracking (SCC) in chloride-bearing environments, which has been verified by tests and service experience. Industry standard corrosion tests conducted by Sandvik, including ASTM G48 and ASTM A923, have shown that SAF 2507 is one of the best materials to replace ASTM 316L for hydraulic and instrumentation tubing on offshore platforms. This follows strong concerns, expressed by leading energy and petrochemical suppliers worldwide, that

At Tubotech 2013, Sandvik displayed its seamless tube and pipe products, including hydraulic and instrumentation tubing for critical applications in the oil and gas industry, heat exchanger tubes for the petrochemical industry, high temperature tubes for processing operations, and hollow bars for machining applications. Used in industrial, engineering, food manufacture, pulp and paper, chemical and petrochemical plants, Sandvik hydraulic and instrumentation tubing is also deployed in oil and gas exploration and production facilities, due to its resistance to corrosion. The tubes can be supplied in straight lengths or coiled to suit individual applications. In coiled form the tubes facilitate the installation of long runs, reducing the number of connections, ensuring system integrity and providing easier installation with reduced operational and lifecycle costs. As part of its product offering, Sandvik can supply complete system packages, including welded tube and pipe, fittings, flanges and welding consumables, allowing complete single sourcing. The company’s Sanmac ® stainless steel hollow bar, with optimised machining properties for reduced tool wear and higher cutting speeds, contributes to increased productivity in component manufacture. Available in a wide range of sizes, Sanmac hollow bar can reduce the cost per component produced while freeing up valuable machine time and cutting material waste.

Hydraulic and instrumentation tubing

316L, are prone to corrosion in exposed locations.

Tests and service experience demonstrate that Sandvik SAF 2507 is less prone to corrosion than most commonly used steels in chloride-heavy environments. The pitting resistance equivalent (PRE) number is calculated from the content of Cr, Mo and N present in an alloy, and is regarded as an ideal reference point defining a material’s resistance to pitting corrosion. For aggressive topside applications a high PRE number of 40 is considered suitable. For example, the minimum PRE number for subsea applications, such as seawater injection systems and umbilical tubes, is 40 and 42.5 respectively. While ASTM 316L and its variants have insufficient PRE values to withstand such corrosive environments, even working at the upper limits of their standards, Sandvik SAF 2507 has a minimum standard PRE of 42.5 – above the minimum PRE requirement of 40, and also significantly higher than that of medium-alloy Duplex stainless steels like UNS S31260, which has a minimum PRE of 33. Other advantages of Sandvik SAF 2507 include its minimum proof strength of 550 MPa (N/mm 2 ), which is nearly twice that of high-alloy austenitic steels due to its combination of austenitic and ferritic phases. Its mechanical strength can also enable lighter constructions. Sandvik Materials Technology – Sweden www.smt.sandvik.com

the quality of austenitic stainless steels has become poorer in the last decade. Sandvik, multinational energy and petrochemical bodies are concerned that pricewise- aggressive suppliers are changing the amounts of certain alloying elements in stainless steels to reduce costs, meet competition and satisfy growing global demand for the material. The widely used standard stainless steels, such as ASTM According to

Stainless steel tube supply from Sandvik

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November 2013 Tube Products International