Tubes

TUBE Tube is always referred to by Outside Diameter (O.D) and Wall Thickness. Tube refers to cylindrical, square, rectangular or any shape of hollow material of uniform thickness that is defined by the outside diameter and wall thickness dimensions. For example, an appropriate description to specify a tube size would be, "1-1/2 inch O.D. tube with a 1/8 inch wall thickness."

METAL TUBES Metal tubes can be categorized mainly in three categories 1. 2. 3.

Seamless tubes Welded tubes Welded and redrawn

Commonly used tube materials are 1. Steels and stainless steels 2. Nickel and nickel alloys 3. Titanium and titanium alloys 4. Copper, brass, bronze etc.

SEAMLESS TUBES As the name suggests seamless tubes are tubes without any seam. These tubes are manufactured by mainly two methods. • Cold rolling • Cold drawing Cold rolling involves reduction of cross-section of tubes by rolling through a die, ID and thickness is maintained by Mandrel inside the pipe / tube. Cold drawing involves reduction of cross-section of tubes by tension through a die and fixed or floating plug.

Apart from above tubes and pipes can be formed by other processes, like forged, tunned, bored, etc depending upon the requirement. These tubes are used for various applications such as the manufacture of bearings, heat exchangers, boilers, automobile parts, drill rods etc. Seamless copper and copper alloy tubes

Tubular products in various sizes, shapes and alloys Common materials are Copper nickel alloys

• Niton 10 (Copper nickel 90/10) • Niton 30 (Copper nickel 70/30) • Iperniton (66/30/2/2 Copper nickel) etc. Brass

• Cubral (aluminum brass) • Admiton (admiralty brass) • Braton (70/30 arsenical brass) • Cupral 55 (94/6 aluminium brass) etc. Commonly followed standards are

ASTM/ASME, DIN BS, AFNOR, NF, JIS. Applications Heat exchangers, Desalination equipment, power station, petrochemical industry, air conditioning and refrigeration WELDED, WELDED AND REDRAWN TUBES Welded and redrawn tubes are being used as an alternative to costly seamless tubes for a number of critical industrial applications. The tubes are welded and then drawn through a die to achieve the required diameter and wall dimensions. The drawing procedure creates a homogenic grain structure between the weld seam and the base tube, which gives the tube greater strength. The more times the tubes are drawn, the greater the tube strength becomes, and the performance of the tubes can be compared to that of seamless tubes.

The welded tubes are destined to be used in the most critical areas of fundamental plants such as conventional and nuclear power stations, petroleum refineries, chemical and petrochemical plants, heat exchangers and sugar mills. The welded redrawn tubes are mainly used in the automotive, chemical and automation industries. Welded tubes can be of following materials 1. Stainless steels (austenitic, super austenitic, ferritic, duplex, super duplex etc.) 2. Nickel base alloys Commonly followed standards are ASTM, ASME, DIN, AFNOR, BSI etc. Steel tubes Tubular steel products are normally classified according to method of manufacture or intended use. Heat exchanger tubes are used in all kinds of industries. Used primarily in tubular heat exchangers, they are made from strip and welded without filler metal. The tubes have a bead worked weld and are heat-treated. They are most commonly delivered in fixed lengths. Heat exchanger tubes:

Hygienic tubes have to satisfy stringent demands as regards surface finish. The main application is pipe systems handling food and beverages. Hygienic tubes:

Structural tubes:

High-strength welded steel tubes are used as structural elements in buildings and other structures and a variety of manufactured products. It is produced in round, square and rectangular shapes. Benefits include aesthetic appeal, high strength-to-weight ratios, uniform strength, cost effectiveness and recyclability. Drawn (over mandrel) tubes: The manufacturing

process for DOM tubing begins with coils of steel, which are slit to the proper width for the desired tube size. The strip is cold formed and passed through an electric resistance welder, which joins the edges together, under pressure, to complete the tubular shape. Then the tube is cleaned and annealed, and one end of each length is squeezed to a point so it can be gripped by the drawing mechanism. The tube is then drawn through one or more dies and over mandrels. This reduces the diameter of the tube and thins its walls to the required dimensions in a controlled fashion to provide the qualities desired in the finished product. Various applications • • • •

Environmental: Equipment for heat recovery and waste incineration. High temperature: Recuperators in the steel industry Water treatment: Heating coils Chemical industry: Heat exchangers and evaporators in the production of soda, ethylene oxide, fertilizers, etc. • Energy: Heat recovery and gas cleaning

• • • •

Food: Production of sugar, fruit juices, etc. Pulp & paper: Liquor heaters and evaporators Oil & gas refineries: Oil coolers, sour water strippers, etc. Moving components: Auto and truck axles, high-speed shafts, printing, textile and paper mill rolls, telescoping cylinders, tool extensions

Copper tubes Long lasting copper tube is a favorite choice for plumbing, heating, cooling and other systems. There are the seven standard types of copper tube, which are manufactured to meet ASTM standards. Types K, L, M, DWV and Medical Gas tube are designated by ASTM standard sizes, with the actual outside diameter always 1/8-inch larger than the standard size designation. Each type represents a series of sizes with different wall thickness. Type K tube has thicker walls than Type L tube, and Type L walls are thicker than Type M, for any given diameter. All inside diameters depend on tube size and wall thickness. Copper tube for air-conditioning and refrigeration field service (ACR) and natural gas (Type G) are designated by actual outside diameter. "Temper" describes the strength and hardness of the tube. In the piping trades, drawn temper tube is often referred to as "hard" tube and annealed as "soft" tube.Tube in the hard temper condition can be joined by soldering or brazing, using capillary fittings or by welding. Various applications • • • • • • • • •

Underground Water Services Water Distribution Systems Chilled Water Mains Drainage and Vent Systems Heating Fuel Oil, L.P. and Natural Gas Services Nonflammable Medical Gas Systems Air-Conditioning and Refrigeration Systems Fire Sprinkler Systems

Titanium and titanium alloy tubes Titanium tubes are light in weight, very strong and resistant to heat and corrosion. They are, therefore, widely used for power generation, desalination, chemistry, military, aviation and space. As products very difficult to produce or weld, however, they can be manufactured only when supported by high level of tube forming technology. Demand for titanium tube is high in the chemical and oil refining industries where high purity and corrosion resistance are essential. It is also used at a nuclear or thermoelectric power plant where heat exchangers are used.

NON-METALLIC TUBES Plastic tubes Typical Plastic Materials include: • HDPE (High Density Polyethylene) • LDPE (Low Density Polyethylene) • PETG • Flexible PVC • Butyrate • Polypropylene • Polystyrene • ABS • Santoprene • Polycarbonate Typical Applications • Rigid Plastic Tubing for Structural Application • Flexible Hose Tubing • Packaging Tubes • Dip Tubes • Beverage Tubing • Irrigation Tubes • Feeder Tubes • Bird Feeder Tubing ASTM: means American Society for Testing and Materials. ASTM provides technical standards to industry worldwide standards for materials, products, systems, and services. Following are the details for some most commonly used tube standards for more details Click here ASTM A 161 (Seamless Low Carbon And Carbon Molybdenum Steel Still Tubes For Refinery Service) ASTM A 178 (Electric Resistance Welded Carbon Steel Boiler Tubes) Gr A / Gr C / Gr D ASTM A 179 (Seamless Cold Drawn Low Carbon Steel Heat Exchanger and Condenser Tubes) ASTM A 192 (Seamless Carbon Steel Boiler Tubes for High Pressure Service) ASTM A 200 (Seamless Intermediate Alloy Steel Still Tubes for Refinery Service) T4 / T5 / T7 / T9 / T11 / T21 / ASTM A 199(Seamless Cold Drawn Intermediate Alloy Steel Heat Exchanger and Condenser Tubes) ASTM A 209 (Seamless Carbon Molybdenum Alloy Steel Boiler and Super heater Tubes) ASTM A 210 (Seamless Medium Carbon Steel Boiler and Super heater Tubes) Gr A-1 / Gr C ASTM A 211 (Spiral Welded Steel or Iron Pipe) A570-30 / A570-33 / A570-36 / A570-40 / A570-45 / A570-50 / ASTM A 213 (Seamless Ferritic and Austenitic Alloy Steel Boiler Super heater and Heat Exchanger Tubes) T2 / T5 / T5b / T5c / T7 / T9 / T11 / T12 / T17 / T21 / T22 / T91 / 18Cr2Mo / TP201 / TP202 / TP304 / TP304H / TP304N / TP304L / TP304LN / TP309CB / TP309H / TP309HCb / TP309S / TP310Cb / TP310H / TP310HCb / TP310S / TP316 / TP316H / TP316N / TP316L / TP316LN / TP321 / TP321H / TP347 / TP347H / TP348 / TP348H / XM-15 / S30815 / S31050 / S21500 / S31725 / S71726 / S32615 / ASTM A 214 (Electric Resistance Welded Carbon Steel Heat Exchanger and Condenser Tubes) ASTM A 226 (Electric Resistance Welded Carbon Steel Boiler and Super heater Tubes for High Pressure Service) ASTM A 249 (Welded Austentic Steel Boiler Super heater Heat Exchanger and Condenser Tubes) ASTM A 250 (Electric Resistance Welded Carbon Molybdenum Alloy Steel Boiler and Super heater Tubes) T1 / T ASTM A 254 (Copper Brazed Steel Tubing)

ASTM A 268 (Seamless and Welded Ferritic Stainless Steel Tubing For General Service) TP405 / TP410 / TP429 / TP430 / TP443 / ASTM A 269 (Seamless and Welded Austenitic Stainless Steel Tubing for General Service) ASTM 270 (Seamless and Welded Austenitic Stainless Steel Sanitary Tubing) TP304 / TP304L / TP316 / TP316L, etc.) ASTM A 271 (Seamless Austenitic Chromium Nickel Steel Still Tubes for Refinery Service) TP304 / TP304H ASTM A 334 (Seamless and Welded Carbon and Alloy Steel Tubes for Low Temperature Service) Gr 1 / Gr 3 / Gr 6 / Gr 7 / Gr 8

Reference URL’s 1. http://www.ast.avestasheffield.com/tech_support/docs/ast_021118E.pdf 2. http://www.sitindustrie.com/inglese/tubi%20rame%20inglese.html 3. http://www.copper.org/tubehdbk/tables/table1.html 4. http://www.seilerpc.com/plastic-tubes.htmls