Carbon steel pipe

Feedwater treatment is designed to protect the feedwater system and, to some extent, the boiler. Most systems contain carbon steel piping. Carbon steel corrosion (Fig. 23a) is considerably slower at a pH between 9.0 and 11.0. In aH-ferrous feedwater systems, the preferred pH range is therefore 9.2 to 9.6, although some systems are operated at a pH as high as 10. In systems where copper alloys are present, high concentrations of ammonia accelerate corrosion of the copper alloys. In those systems the preferred pH is 8.8—9.2. 

Lined pipe collapsed at gasket area or ID due to buildup of corrosion products between liner and carbon-steel pipe. 

TABLE 10-39 Cement-Lined Carbon-steel Pipe ... 

Half-inch copper tubing is commonly used for steam tracing. Three-eighths-inch tubing is also used, but the effective circuit length is then decreased from 150 feet to about 60 feet. In some corrosive environments, stainless steel tubing is used, and occasionally standard carbon steel pipe (one half inch to one inch) is used as the tracer. 

Apphcations requiring accurate temperature control are generally limited to electric tracing. For example chocolate lines cannot be exposed to steam temperatures or the product will degrade and if caustic soda is heated ove 150°F it becomes extremely corrosive to carbon steel pipes. 

L-shaped pipe section of 2 in. (5 cm) carbon steel pipe socket welded to a 90° carbon steel elbow... 

Figure 5.18 Heavily fouled and corroded internal surface of a galvanized carbon steel pipe.

Attack at welds due to bacteria is possible, but it is not nearly so common as is often supposed. Because of residual stresses, microstruc-tural irregularities, compositional variation, and surface irregularities, welds show a predisposition to corrode preferentially by most corrosion mechanisms. Attack is common along incompletely closed weld seams such as at butt welds in light-gauge stainless steel tubing (Fig. 6.9A and B). Attack at carbon steel welds may occur. Figure 6.10 shows a severely corroded carbon steel pipe from a service water sys-... 

Figure 6.10 A perforated carbon steel pipe at a weld-backing ring. The gaping pit was caused by sulfate-reducing bacteria (see Case History 6.1).

Figure 6.18 Pinhead-sized, shell-like organisms covering a carbon steel pipe surface.

Sample Specifications 3.5 in. (8.9 cm) outer diameter, carbon steel pipe, wall thickness -0.225 in. (0.572 cm)... 

Sample Specifications 4 in. (10 cm) inner diameter, schedule-40 carbon steel pipe... 

Figure 7.2 Carbon steel pipe attacked by a strong mineral acid.

Carbon steel piping, valves, structurals and vessels operating at cryogenic and ambient temperatures. 

Carbon steel piping shall include at least 1/8 inch allowance for corrosion. 

For example, for 3-in. nominal carbon steel pipe, the Schedule 40 wall thickness is 0.216 in. If the pressure required in the system, needs 0.200 in. wall and... 

P. I. C. Guimaraes, A. P. Monteiro, and F. B. Mainier. New corrosion inhibitors in solid form to protect carbon steel pipes in acidizing operations. In Proceedings Volume, volume 2. 5th Brazil Petrol Congr (Conexpo Arpel 94) (Rio De Janeiro, Brazil, 10/16-10/20), 1994. 

Estimate the optimum pipe diameter for a water flow rate of 10 kg/s, at 20°C. Carbon steel pipe will be used. Density of water 1000 kg/m3. 

Replace with the same schedule carbon steel pipe and accept renewal at 3-year intervals. 

Design a double-pipe exchanger for this duty, using standard carbon steel pipe and fittings. Use pipe of 50 mm inside diameter, 55 mm outside diameter for the inner pipe, and 75 mm inside diameter pipe for the outer. Make each section 5 m long. The physical properties of the caustic solution are ... 

D. After 2 years exposure, five out of six pieces of carbon steel pipe were attacked. One piece of pipe was unaffected. 

G. After 2 years service, all parts of carbon steel pipe, including weld and heat-affected zones, were satisfactory. 

A 106 Seamless Carbon Steel Pipe for High-Temperature Service [Note (2)]... 

Table IX-5B Carbon Steel Piping Materials Performance Factor, Mf...

ASTMAI06 Seamless carbon steel pipe for high-temperature service I7I75 3602 NFA 49.211 G3456... 

ASTM A524 Seamless carbon steel pipe for atmospheric and lower temperatures G3460... 

TUBING CARBON STEEL PIPE STAINLESS STEEL O AUXILIARY FLUSH PLAN... 

SEAL CHAMBER DATA (2.1.6Q.1.7) temperature (°C) PRESSURE (kPa) FLOW (m /h) n SEAL CHAMBER SIZE /TABLE 2.3) TUBING O CARBON STEEL PIPE STAINLESS STEEL PIPINGASSEMBLY (3.5.2.10.1) THREADED O UNIONS SOCKET WELDED FLANGED TUBE TYPE FITTINGS PRESSURE SWITCH /PLAN 52/53) TYPE... 

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