316-grade stainless steel

The stream from the reactor consisting of a mixture of urea, unconverted ammonium carbamate, excess water, and NH, is fed into the top of the stripper. The ACES stripper utilizes a ferrite—austenite stainless steel, as do the carbamate condensers. The reactor and scmbber are constmcted with 316 L urea-grade stainless steel. 

Flame arrester of high-grade stainless-steel mesh... 

Ogundele and White carried out a series of polarisation studies on surgical grade stainless steels in Hanks s physiological solution. Under... 

Ogundele, G. I. and White, W. E., Polarization Studies on Surgical-Grade Stainless Steels in Hanks Physiological Solution , in Corrosion and Degradation of Implant Materials, second symposium, (Eds) A. C. Fraker and C. D. Griffin, 117-135 ASTM Publication STP 859, Philadelphia (1985)... 

In summary, preliminary results from two animal models (rabbit and mouse) indicate that poly(N-palmitoylhydroxyproline ester) elicits a very mild, local tissue response that compares favorably with the responses observed for established biomaterials such as medical grade stainless steel or poly(lactic acid)/poly(glycolic acid) implants. At this point, additional assays need to be performed to evaluate possible allergic responses, as well as systemic toxic effects, carcinogenic, teratogenic, or mutagenic activity, and adaptive responses. 

CS = carbon steel SS (low grade) = low-grade stainless steel, for example, type 304 SS (high grade) = high-grade stainless steel, for example, type 316... 

Example 2.1 A new heat exchanger is to be installed as part of a large project. Preliminary sizing of the heat exchanger has estimated its heat transfer area to be 500 m2. Its material of construction is low-grade stainless steel, and its pressure rating is 5 bar. Estimate the contribution of the heat exchanger to the total cost of the project (CE Index of Equipment = 441.9). 

After purification, 316L grade stainless steel is used. This is resistant to corrosion and is electropolished and passivated to reduce roughness, which may act as sites for bacterial growth and future corrosion. 

Figure 3.4. Diagram of a typical jacketed processing vessel. Such vessels are usually made from high grade stainless steel. By opening/closing the appropriate valves, steam or cold water can be circulated through the jacket. In this way, the vessel s contents can be heated or cooled, as appropriate. In addition, passage of steam through the jacket of the empty vessel will effectively sanitize its internal surfaces...

WFI is quite corrosive, especially at 85°C, and it can promote leeching from even high-grade stainless steel piping. Addition of ozone to the WFI can alleviate this, as the ozone s microcidal properties facilitate prolonged storage/circulation of the water at 25°C. Other innovations in this field include replacement of stainless steel pipework with chemically inert plastics. However, extensive tests need to be undertaken in order to prove that WFI cannot leach potentially dangerous substances from these plastics before their use will become routine. 

Humidifiers serving clean areas and process areas should use only clean steam for humidification. Carbon steel piping and headers are not acceptable 316L grade stainless steel should be used. All humidifier components (main body, valves, piping, manifold, etc.) should be made of 316L stainless steel. 

Phosphoric acid is corrosive to most construction materials and rubber-lined steel or food-grade stainless steel holding vessels are generally recommended. 

A stainless steel mixing vessel, fabricated from 316 grade stainless steel with some form of cover that allows access for ingredient addition, is an ideal unit for mixing dilutables. The vessel is normally fitted with a stirrer, the power and design of which take account of whether sugar is to be added as a crystalline solid (and thus dissolved) or added as a syrup. Either a top-mounted propeller stirrer or a side-entry unit will mix components adequately, especially if the inside surface of the vessel is fitted with fixed baffles. The use of a stirrer that creates a sufficient vortex to draw in air should be avoided. 

Stainless steel is the metal least affected by methanol. Most of the experience to date has been with the higher grade stainless steel alloys such as 304. It is unknown how well alloys such as 409 might work, but given the good performance of carbon steels with methanol, it is likely that components made from 409 would fare well. 

Structural materials longevity/cost Superior. Standard reactor-grade stainless steels for low temperature loop will perform acceptably over 30 year life and at lower cost compared to high temperature loop. 

Starches often contain a substantial amount of salt (sodium chloride or sodium sulfate) as a residue from the modification process. Small quantities of salt in a hot starch dispersion will attack low-grade stainless steel and can cause severe corrosion of tanks, pipelines and coating application equipment. The salt content should not exceed 0.2% or 2000 ppm chloride. 

The duplex grade stainless steels are also used in shell and tube-heat exchangers because of their high resistance to SCC and lower thermal expansion than austenitic steels. These steels are also used in high-pressure piping and also in systems requiring high-erosion resistance. 

The process is characterized by low-operating temperatures and pressures, which allow all equipment to be constructed from either carbon steel or low-grade stainless steels. It allows ethyl acetate to be made without requiring acetic acid as a feed material. The process is appropriate for both synthetic ethanol and fermentation ethanol as the feed. The synthetic ethanol can be impure ethanol without significantly affecting the conversion or selectivity. The product ethyl acetate is greater than 99.95%. 

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