Reduce costs, be more efficient and good managers consistently search for ways to streamline business processes. This also applies, obviously, to the company of generation processing and managing fluids. Associated equipment and managers who oversee the acquisition of the required tanks need to comprehend the variety of accessible tank alternatives, along with procurement as well as maintenance costs and the function tanks play within their specific applications.
Tanks used in processing need to satisfy specific standards and criteria according to the particular procedure or phase of its direction and fluid types included. This is particularly so in high-purity water, biopharmaceutical, food-related and lab applications. Here, tanks are custom built and expensive. But prices in this region could be reduced by picking tanks produced from stuff other than the old standby, stainless steel.
"Stainless" has long become the automatic option in sectors where high purity, simple cleanability, and entirely repeatable processes are critical. It's glossy and appealing; it's not false, and it just feels like the appropriate choice -- or even the sole alternative -- to lots of businesses needing tanks for storage and processing. Many in the industry continue to recite the "untarnished mantra" when it comes to tanks and tank stuff. Nevertheless, to get an excellent number of uses, today's plastic tanks supply better performance or the same -- often at a reduced cost and with shorter lead times.
Choices to stainless
Application details themselves go a very long way in answering the question concerning which tank substance is more proper. Most significant is understanding the properties of the complete array of procedure or storage demands and the materials handled. Quite simply, if a tank is open to the atmosphere and extremely high temperatures aren't demanded, you do not need steel. Answers to a few other key questions about the fluid and program requirements help determine whether a stainless or plastic tank is the pick that is right.
First, what is the process pressure inside the tank? If it is likely filled or emptied quicker than the vents of the tank allow air to move, stainless steel may be required. That is so because of the tensile strength under pressure of steel. It also can more easily be fabricated to resist vacuum situations.
However, while a plastic tank molded from polyethylene (PE) or polypropylene (PP) has less ability to withstand differential pressure, it might be fitted with unique hardware to enable it to balance atmospheric pressure and maintain the tank's integrity.
Next, define dimensional tolerances. A molded plastic tank could have dimensional tolerances as big as /- 3%, and, with temperature change, it expands and contracts a lot more than steel. This change and variability can be accommodated with simple measures, for example, hose or flexible piping used for pipes connections. In those rich applications that need all pipes to be rigid, stainless steel is the leading option.
One other important factor is temperature. What's the temperature of the fluid to be stored?
Polypropylene tanks function very well in heat- sanitized ultrapure water systems, water -for- injection applications for handling liquids up to 100 C., along with other processes that call
Eventually, do you know the physical and chemical properties of the material that will fill the container? Even some detergents with exceptionally strong surfactants, solvents, petroleum products and abrasive substances ought to be stored and processed in high-grade stainless steel since they can cause the plastic to degrade.
The likelihood of corrosion is higher as the concentration of chlorides acids or oxides corrosion also occurs more readily in high-temperature processes. Before making the ultimate choice of a tank and tank stuff, the process manager needs to understand the properties of the fluid available.
Comparing costs
Plastic can deliver significant savings for processing a specified fluid that's compatible with stainless or plastic. That is true regardless of whether the comparison is to lower-cost 304 steel or higher-level 316L.
With tanks that were bigger, savings are realized more than cost concerning time; substantial stainless tanks typically take from 12 to 20 weeks to fabricate and deliver, compared to 6 to 10 weeks for poly tanks.
Alloys including Hastelloy and specialty polymers, for example, PVDF are instantly out of the running when cost is a factor. And while Teflon has a high-temperature capacity and is impervious to almost everything, it, also, is pricey -- as making manufacture complex and dangerous as well.
Plastics clearly lead the way for easy manufacturing -- translating instantaneously into shorter lead times and lower prices. Polymers could be modeled and fabricated into a wide selection of sizes, shapes as well as styles, including the flat bottom, cone bottom, open top and dome top (a necessity for ultrapure water uses) -- all with less difficulty and expense than when working with stainless steel.
Plastic's other advantages
If pigments are omitted, plastic tanks can be -- and often are -- made to be translucent. Fluid degrees can be determined at a glimpse, whereas tanks produced from stainless have mechanical gauges, seeing interfaces, electronic detectors or alternative devices to track shifting volumes.
Interestingly enough, translucence can be a requirement for certain specialized uses. Here, sunlight is a must, and so the opaque stainless tank is not a choice with this process.
Other specialized processes that are better suited to the utilization of poly tanks are those with high-purity conditions, such as biopharmaceutical uses. As long as discussed previously as the fluid at hand is just not acidic or highly abrasive, it's better suited to some plastic tank due to the material's resistance. Stainless steel, notably the lesser grades, is frequently subject to unfavorable chemical reactions between the tank and the tank contents, causing pits to form on the interior surface. These regions can be nucleation sites for bacteria, promptly contaminating the contents. This is particularly damaging in the pharmaceutical and food sectors, where firms must attest a 100% repeatable cleaning process -- something that can't be reached with a pit-damaged tank.
Plastic tanks also offer exceptional performance in ultrapure water (UPW) uses. Because this rusty deposit is usually red (even though it may range from orange to black), the phenomenon is called rouging. The deposit that is rouging covers the tank and is distributed and deposited through the entire processing system -- obviously an unacceptable situation. Plastic used in tank fabrication, though, is chemically inert, so it's immune to rouging and corrosion.
The safe choice?
Stainless steel has a sizable following in business. This is perhaps more because of human nature than good science. Sometimes it's just force of habit; using steel is just "what we do," they say. Others succumb to the over-engineering syndrome -- it is a safer bet, and safer is better. And you will find several who simply are not aware of their other options.
However, like how many engineers who exclaim, "I didn't understand you could weld plastic!" falls, the number of thermoplastic tanks put into use is growing. Finally, when businesses begin to look difficult in the options -- all the choices -- they are more likely to embrace plastic tanks in greater amounts.
Plastic is becoming ubiquitous in an industry -- and in regular life -- due to its great versatility as a problem solver. That is so when it comes to fluid management. Where they are well-satisfied supervisors, who make decisions that are informed and use plastic tanks can save significant time and money while enhancing their production and processing capacities. The overall result is going to be a business that moves ahead -- and stays of the contest.