Steam-traced line

Boiling of liquid in line to or from DP cell due to a steam leak in the steam tracing line... 

In view of its properties (bpi.013 249 C, mp = 122°C. sublimation at 100°CJ, the storage and handling of benzoic acid require special precautions (heated tank, steam traced lines, etc). 

Its lower melting point avoids the necessity for steam tracing lines and equipment, especially for outdoor winter operations. 

Steam-traced line Process line, primary flaw Process line, secondary flow Steom end eihoust lines Woler line... 

Provide steam tracing lines, i.e., another steam line in contact with or in the near vicinity of the liquid SO3 pipeline instead of a steam jacket. 

Provide steam tracing and adequate insulation thereafter to the vessels, pipelines, valves, etc., to prevent solidification of oleums. Steam jackets should be avoided due to danger of steam leaking inside. The steam tracing lines should not directly touch the vessels or pipes as local hot spots can develop. 

Covers for all motors, starters, and light fittings shall be provided in advance to protect from heavy rains. Plant units may be operated at slightly higher temperatures. Steam jacketing may be provided to pipes to prevent solidifications in pipes. If there are chances of an accident due to ingress of steam in the pipes, then steam tracing lines shall be installed. 

Heat tracing In many processes, equipment, instruments, and piping systems require externally applied heat. This heat may be applied by electrical tracing leads attached to the item or line or through a small bore pipe or tubing that carries steam or other heating media (e.g., hot oil). An example of a steam-traced line is shown in Exhibit 1-10. 

FATTY ACIDS. RCOOH. Laboratory tests have shown that fatty acids cause mild attack of 1100 alloy at ambient temperature. Anhydrous fatty acids were found to be veiy corrosive to aluminum alloys at the boiling point in other laboratoty tests. Aluminum alloy storage tanks, separators, settling and receiving tanks, condensers, vapor lines, and steam trace lines have been used to process and handle fatty acids and fatty acid derivatives. See also Ref (1) p. 132, (2) p. 274, (3) pp. 125, 127, (4) pp. 25, 100, (7) p. 93. 

When winterizing is required, the steam tracing and insulation should include the first 7.5 m of the flare stack above the vapor inlet and also in the case of a drum seal, the vapor line from the seal drum to the flare. Where steam injection to one of the smokeless tips, as shown in Figures 11 B and C is used, then the steam ring should remain outside the top of the flare tip (i.e., not internal). Where severe ambient conditions are encountered then it is recommended that the entire seal drum and flare be insulated in addition to steam tracing and open steam injection at base of flare. 

A similar incident occurred on another furnace when the heat transfer oil froze inside the furnace during unusually cold weather. Outside the furnace, the lines were steam-traced. The operating team decided to thaw the frozen oil by lighting one of the burners... 

Where the acid condensate is corrosive and neutralisers cannot be used, then a condenser of resistant materials has to be employed. However, by steam tracing the lines leading the vapour to the condenser, premature condensation can be avoided (Fig. 9.6) and in consequence a cheaper material may be used. 

Traps should be fitted to steam heated tracing lines, rather than allowing them to blow to the atmosphere (as is common), to avoid a direct steam loss. 

Often it is necessary to heat transfer lines to ensure that products do not gel in the line during cold weather. Both electrical heating and steam heating can be used to trace lines. Only explosion proof electrical heat tape and thermostats can be used on fuel systems. Immersion heaters are not recommended for fuel and fuel additive applications. 

When taking gas samples, the goal is to obtain representative samples with minimum time lag, using short, small-volume sampling lines. Whenever possible, it is preferred to draw dry and clean samples to minimize the need for filters, dryers, knockout traps, or steam tracing. 

This cylindrical, low-pressure, horizontal tank had a design rating of about 5 psig (0.3 bar). A steam coil heated this tank. The transfer line to the tank was steam traced and insulated to keep it clear, but the heat tracing and insulation system on the inlet transfer piping was less than ideal. The inlet piping had to be dismantled on several occasions to clear it because of solidification in the fine. (See Figure 6—18.) [7]... 

The effluent from the reaction boiler is handled in type 310 (UNS S31000) SS above 800° F (425° C), type 321 or 347 (UNS S34700) SS above 500°F (260°C), and carbon steel below 500°F (260°C). Molten sulfur is handled in steam-traced steel or aluminum. At the discharge to the pits, oxygen causes severe attack on steel, so the discharge end of the steel line often contains a short piece of alloy 20. 

The possibility of solidification of the fluid should not be overlooked in the design of a piping system. Insulation, steam tracing, and sloping the line to drain valves are methods for handling this type of problem. 

Throughout this distillation section, the lines must be steam traced and the pumps... 

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