Seamless

Furnaces of this type, such as the steam locomotive furnace—boHet design, had the obvious disadvantage that pressure was limited to ca 1 MPa (150 psi). The development of seamless, thick-waH tubing for stationary power plants (ie, water-tube furnaces) and other engines for motive power, such as diesel—electric, has in many cases ecHpsed the fire-tube boHet. For appHcations calling for moderate amounts of lower pressure steam, however, the modern fire-tube boHet continues to be the indicated choice (5). 

Fig. 8. Shell-and-tube heat exchanger A, shell of high strength B, tube sheet C, tubes (normally small diameter tubes are seamless, but large diameter tubes (>1 in.) are welded tubes) D, boimets E, baffles to assure more efficient circulation by providing minimum clearance between tubes and tube holes...

A Russian ammonia pipeline of nearly 2400 km extends from Togliatti on the Volga River to the Port of Odessa on the Black Sea, and a 2200-km, 250-mm dia branch line extends from Godovka in the Ukraine to Panioutino. The pipeline is constmcted of electric-resistance welded steel pipe with 7.9-mm thick walls but uses seamless pipe with 12.7-mm thick walls for river crossings. The pipeline is primed and taped with two layers of polyethylene tape and suppHed with a cathodic protection system for the entire pipeline. Mainline operating pressure is 8.15 MPa (1182 psi) and branch-line operating pressure is 9.7 MPa (1406 psi) (11). 

One successful total artificial heart is ABIOMED s electric TAH. This artificial heart consists of two seamless blood pumps which assume the roles of the natural heart s two ventricles (Fig. 7). The pumps and valves are fabricated from a polyurethane, Angioflex. Small enough to fit the majority of the adult population, the heart s principal components are implanted in the cavity left by the removal of the diseased natural heart. A modest sized battery pack carried by the patient suppHes power to the drive system. Miniaturized electronics control the artificial heart which mns as smoothly and quietly as the natural heart. Once implanted, the total artificial heart performs the critical function of pumping blood to the entire body (6). 

SmaH quantities of carbon tetrachloride can be shipped in 1, 5, and 55 gaHon (208 L) metal containers. Larger quantities are shipped by tank tmck, tank car, barge, and ship. Seamless stainless steel. Teflon, or seamless bronze hose is recommended with asbestos. Teflon, Viton, or neoprene gaskets. Special precautions should be taken to prevent contact with aluminum, magnesium metal, and their aHoys (48). 

Copper and Copper Alloys Seamless copper, bronze, brass, copper-nickel-aUoy, and copper-silicon-aUoy pipe and tubing are produced by extrusion. Tubing is available in outside-diameter sizes from Vi6 to 16 in and in a range of wall thicknesses varying from 0.005 in for the smallest tubing to 0.75 in for the 16-in size. Tubing is usually specified by outside diameter and wall thickness. 

Seamless copper tubing is sold in water-tubing sizes (ASTM B88 and B306). These sizes are identified by a standard size designation dimensionally Vh in less than the nominal outside diameter. The tubing is also sold as outside-diameter copper tubing (ASTM B280). 

Copper-silicon alloy (96 percent cooper, 3 percent silicon, 1 percent manganese), per ASTM B315, is furnished as seamless pipe and welding fittings in Schedule 10 and regular and extra-strong copper pipe thicknesses. It is easier to weld than copper. 

Zirconium (Tin 1.2 to 1.7 Percent) Tubing is available seamless ranging from outside diameter by 0.030-in wall to 8-in outside diameter by 0.4-in wall, and welded up through 30-in outside diameter by VH-in wall. Cast valves and fittings are also available. 

Asbestos Cement Asbestos-cement pipe is seamless pipe made of sihca and portland cement, compacted under heavy pressure, uniformly reinforced with asbestos fiber, and thoroughly cured. The interior surface is smooth, does not corrode, and does not tuberculate. Under normal conditions of operation, asbestos cement will handle... 

Copper and copper alloy Seamless pipe and tubing Copper pipe B42 31 Drawn 102, 120, 122 i/f -2, inclusive 45.0 40.0 9, 27 -325... 

Manufacturing tolerances for steel, stainless-steel, and nickel-alloy tubes are such that the tubing is produced to either average or minimum wall thickness. Seamless carbon steel tube of minimum wall thickness may vaiy from 0 to 20 percent above the nominal wall thickness. Average-wall seamless tubing has an allowable variation of plus or minus 10 percent. Welded carbon steel tube is produced to closer tolerances (0 to plus 18 percent on minimum wall plus or minus 9 percent on average wall). Tubing of aluminum, copper, and their alloys can be drawn easily and usually is made to minimum wall specifications. 

Defects in finished components can sometimes be traced as far back as casting problems in the ingot or billet from which the component was eventually produced. Defects in welded tubes may be linked to defective metal or to the welding process itself Defects in seamless tubes can originate in extrusion or drawing processes. 

Seams. As defects, seams are distinct from weld seams and may be found in nonwelded (seamless) tubes. They are caused by crevices that have been closed by some rolling process but remain unfused. 

Seams. As a defect, a seam is distinct from the seam resulting from a welding process. Seam defects can be found in nonwelded (seamless) tubes. They can originate from blow holes or nonmetallic inclusions in the ingot and are caused by crevices that have been closed by some rolling process but remain unfused. At times, they will appear in a spiral pattern in tubes. Seams can be very tight and appear as hairlines on the surface. They can cause failure when the component is pressurized. 

Sample Specifications 1 in. (2.5 cm) outside diameter, 90 10 cupronickel seamless tube... 

Overhead tanks, purifiers, and degasing drums are covered. All pipe welding is to be done according to Section IX of the ASME code, and all piping must be seamless carbon steel, minimum schedule 80 for sizes inches (38.1 mm) and smaller, and a minimum of schedule 40 for pipe sizes 2 inches (50.8 mm) or greater. 

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