Truly representative sampling, even in dirty air! You spoke…we listened! Our new hydrodynamic design is based on your request for enhanced temperature control and sample system cleanability. We hired a rocket scientist to help design it, so you don’t have to be one to use it. The tip of the diaphragm seals on the ID of the vessel wall resulting in improved tank cleanability. The “V” shape inside the valve chamber creates excellent drainability. A simple “Sample and Steam” valve body allows full steaming while the valve is closed. A unique port allows through-the-chamber CIP/SIP, ensuring a truly representative sample every time. The fittings are angled away from the vessel at a quicker rate allowing closer jacketing to the tank and improved cleanability.

ASEPCO’s valves don’t add complications; instead they are proven to simplify maintenance and reduce downtime. And, they keep on saving you money every year they are in use. Give us a call, we’d love to help you solve any challenge you might have.
Best wishes, Mark

To find out more, go to the Sample Valve web page.

ASEPCO – Thinking Ahead – Saving You Time, Saving You Money, and Improving Your Products.

Phone: 800.882.3886

Email: sales@asepco.com

Enter the 21st Century of Valve Technology… Without Cutting into Your Tank! Tired of the cleaning issues with ball valves or butterfly valves? Alarmed at the cost to cut out that old ball valve and recode your ASME tank to have a cleaner valve solution? Don’t fret, retrofit! Introducing ASEPCO’s Tank Retrofit Valve This bolt-in style flange easily connects to the existing flange on your tank. Imagine having a cleaner tank with: Low installation costs High return on investment Easy to change diaphragms Legendary radial seal design Simple to clean valve technology Get cleaner without breaking the bank.

Designed to be Clean AND Affordable

Innovation Driven by Customer Needs As with many of ASEPCO’s valve solutions the Retrofit Valve was born from necessity.Tired of the cleaning issues with ball valves or butterfly valves, our customers needed to clean their tanks faster. They pleaded with us to give them a practical solution that is cost effective and easy to install. We answered with a bolt-in style flange that easily connects to the existing flange on their tanks. Designed to be Easy on the Pocketbook Forget about re-coding your ASME tanks at a huge expense. Just send us your existing valve specs along with a few details about your tank and we’ll design the proper adapter to get you into the 21st century of clean valve technology. Don’t pay to cut out the old and weld in the new… Instead spend your money wisely on our Retrofit Valve. Give Us a Chance to Save You Money Send us your existing designs and we’ll create a valve that you can install without cutting into your tank. We’ll get you up and running faster than planned and under budget!

Find out more! Visit our Retrofit valve page.

Best wishes, Mark

ASEPCO – Thinking Ahead – Saving You Time, Saving You Money, and Improving Your Products.

Phone: 800.882.3886

Email: sales@asepco.com

Phone: 877-409-8590
Email: info@tru-flow.com
URL: http://www.tru-flow.com

So, why can’t we give you any better answer than “It depends…”?

To begin with, we are never told the exact details of the process. This makes it hard for us valve makers to know what we are dealing with.

Exposure to steam is a major factor in diaphragm aging, and the chemicals in the process are also factors—as well as the CIP and SIP cycles, and the temperatures and lengths of these cycles. Some cycles and chemicals even act synergistically to age the diaphragm.

An aseptic biopharmaceutical application that we know quite well makes a good example. Here, cycle parameters were developed specifically to produce an aseptic CIP/SIP process. Validation is the name of the game for most clients, so no cycle is in any way generic. Each is specially developed, tested and proven to do its part in creating a reproducible aseptic CIP/SIP system.

Because each CIP/SIP cycle is custom developed (and we never know what the product really is to begin with), there is no way we can guess what conditions would be appropriate to test for in the lab. This is why valve makers don’t attempt to simulate your processes. Where does this leave you?

Here’s our advice:

1. Gather data. Find out what is already known about how certain elastomers perform in your process. Become familiar with how well they perform in the different locations and cycles. The gasket material currently used is a good clue to what works.
2. Check the generic chemical resistance charts produced by elastomer makers. This data should tell you what not to select as a diaphragm, which can be very useful.
3. Use your best judgment in diaphragm selection based on actual experience at your facility combined with the resistance tables. Nothing we can suggest can match the value of your experience. Here are some other tips we can share with you based on what our diaphragm users tell us:
   • Observe the diaphragm as it goes into your process and starts to develop a life. We suggest you look at it weekly or twice a month at a minimum. It only takes a couple minutes to do this!
   • Keep your staff on the lookout for any signs of diaphragm wear. Learn what the diaphragm looks and feels like as it ages.
   • Our pickiest clients (parenterals makers) tell us that they like to start with these generic rules to ensure that they change the diaphragm long before it’s needed.
     • For fewer than 5 SIP cycles/week (less than 2 hours each at temperatures under 135°C), consider annual diaphragm changeout.
     • For more than 6 SIP cycles/week (less than 2 hours each at temperatures under 135°C), consider changing out the diaphragms every six months.

Now, keep in mind these are very minimal guidelines. But they are a good rule of thumb. It is critical that you evaluate materials based on your system.

Do you have a materials problem or a diaphragm issue? What are your experiences? We’d love to hear from you!

ASEPCO – Thinking Ahead – Saving You Time, Saving You Money, and Improving Your Products.

Phone: 800.882.3886

Email: sales@asepco.com

First, I would like to thank the Boston Area Chapter of ISPE for honoring me with the second issuance of The Hank Moes Founders Award. It is truly great to be honored by one’s peers and it is really a wonderful thing to see something I started (the Boston Area Chapter’s Product Show) continue to flourish and succeed after my seven year start-up tenure.

We have been involved with promoting cleaning systems for over fifteen years. We currently represent CIP/COP (clean out of place) systems manufacturer Sani-Matic of Madison, WI in the Northeast US. Sani-Matic is a fully integrated CIP/COP skid designer/builder. Sani-Matic builds only cleaning-related equipment. Sani-Matic can do it all in house, stainless steel piping and fabrication, ASME tank fab, control panel fab, and they also do system programming.

CIP is the foundation process in modern aseptic facilities. Good CIP designs provide for efficient, repeatable, and validatable cleaning of aseptic systems. CIP good system design must include the CIP skid at the heart, but must include the consideration of cleaning ALL the equipment to be cleaned, tanks, piping, valves, hoses, mixers, blenders, centrifuges, instrumentation sensors, ad infinitum. The task can seem daunting.

CIP in good process design begins as early as the earliest conception of the process; you cannot start thinking about cleaning too early.

Note: Cleaning requires both physical and chemical processes.

A. Start by trying to understand your Macro cleaning conditions.

1. You will need a global view of your total cleaning job.
2. Understand the range of equipment and circuits to be cleaned.
3. You need to identify your flow and pressure ranges to maintain velocities sufficient to accomplish the job.
4. You may need high flow with low pressure, or low flow with high pressure.
5. Do you require once-through cleaning or rinsing?
6. Can you use recirculation cleaning or rinsing?
7. Do you want to recycle your final rinse water to use as pre-flush on the next cycle?
8. Is the system to be one, two, or more tanks?
9. How much total time do you have to accomplish all these tasks?

B. Understanding your Micro cleaning situation assists in accomplishing the task of understanding the Macro conditions. Each item in the system to be cleaned needs to be evaluated with these four basic questions in mind:

1. Time: How long does it take to clean?
2. Action: How much pressure and flow is required to clean?
3. Chemistry: What chemistry is required to clean effectively?
4. Temperature: What temperature is required to clean effectively?

The CIP Skid should be designed to provide:

1. Adequate flow and pressure
2. Of the appropriate cleaning solutions and rinses
3. At the correct temperatures
4. For the proper amount of time to each cleaning circuit.

Sounds easy here, but the devil is in the details.

If this subject is of interest to you, let us know (email Mark at embury.mark@asepco.com) and we’ll consider exploring CIP/COP and SIP in the future.

Tom Moss has over 35 years of experience in the Biotech industry. He is the owner of T. Moss & Associates, a sanitary process equipment representative in Massachusetts.

The most common metallic material of construction for product contact surfaces in BioPharm applications continues to be 316L stainless steel. In more demanding and corrosive environments, higher alloyed Super-Austenitic (6-Moly) stainless steels, such as AL6XN® (N08367) and 254SMO® (S31254) or Nickel-Chrome-Moly alloys such as Hastelloy® C-22® (N06022) have been successfully used. Now, more than ever, the fluctuating costs of these higher alloys have made these choices increasingly difficult. Due to the commodity surcharges of nickel and molybdenum, costs of producing alloyed steel, including 316L, have increased drastically, impacting the decision of what alloy is chosen.

End users must look at corrosion resistance, product contamination risks, cleanability, etc. when they choose a material of construction. One potential solution currently being investigated is the use of duplex stainless steels. Duplex stainless steels are not new and in fact have been around since the 1930s. Though these alloys were more available and have seen wide range use since the 1970s, they have not achieved common usage in the BioPharm industry as of yet. Duplex stainless steels have a dual-phase metallurgy that is nominally 50% Austenite and 50% Ferrite, which is different metallurgically from alloys like 316L, 6-Moly, and Ni-Cr-Moly alloys, which are fully austenitic. Generally, duplex alloys have a higher Chrome composition, a lower Nickel content, and precise additions of Nitrogen, as compared to conventional 316L. The most common duplex stainless steel is 2205 (see figure 1 for a basic chemistry comparison). Since duplex 2205 contains a much lower Nickel content than 316L, one of the main cost drivers is lowered, thereby making it a cost effective alternative to higher alloys and more in line with 316L in the current market.

Table 1: Alloy Chemistry % (minimum unless otherwise noted). Plate specifications used. Complete composition of alloys is not noted.

Compared to 316L, generally duplex 2205 is more corrosion resistant, especially in chloride containing environments, and is very resistant to chloride pitting and stress corrosion cracking. Other benefits in addition to the corrosion resistance, is greater strength, better fatigue strength, and a lower coefficient of thermal expansion rate as compared to 316L.

The most critical issue in using duplex stainless steels is in the fabrication process. Knowledgeable and experienced fabricators who understand duplex stainless steels should be utilized. The main concern is maintaining the austenite/ferrite balance during welding. This usually requires extra weld procedures and testing requirements (including metallography and corrosion testing), alternative shielding gas selection, and additional quality control measures to be implemented. The weld procedures and processes must maintain heat input and have controlled cooling rates. This is required to avoid the formation of intermetallics which can degrade the corrosion resistance and strength.

Polishing and passivation can be easily performed with most normal processes and techniques utilized with 316L, with some possible modifications. When electropolished, duplex materials can provide a featureless surface similar to that achieved with 316L. Electropolished duplex materials may show a “dual phase” type appearance due to slight “etching” of the two phases; however, this does not appear to have a negative impact in achieving the desired RA readings. Although, not a guarantee, a reduction of non-metallic stringers has also been noticed in comparison with commercially available 316L.

Other duplex stainless steels such as the most recently developed Lean Duplexes (LDX 2101®, AL2003TM) and Super Duplexes (255, 2507, 2906) may also be potential options in the BioPharm industry, although experience with their use in product contact applications is limited. LDX 2101 has been successful in non-product contact surfaces when used for vessel dimple jackets and sheathing applications.

In a joint venture between DCI, ASEPCO, CSI, and a major BioPharm manufacturer, testing of equipment manufactured from duplex materials for corrosion resistance in some worst case process solutions is being done. The entire product contact surfaces of the vessel were fabricated from duplex 2205 material including CSI tank ferrules, a DCI PharMix® agitator, CSI tank trim and components, ASEPCO tank bottom valve, ASEPCONNECT sidewall fitting, and ASEPCO sample valve. The tank also utilized a LDX 2101 dimpled jacket and outer sheathing provided by DCI. ASEPCO provided the valves and ASEPCONNECT in duplex 2205. CSI provided the ferrules and tank trim in duplex 2205, while DCI provided the vessel duplex materials, vessel fabrication, and installation of components.

The availability of tubing and tube fittings is currently an issue due to the availability of pharmaceutical-grade tubing fabricated from duplex alloys. Testing has shown over-alloying with AL6XN or C-22 is a very cost-effective solution for these types of components.

As with any material selection process, one needs to be sure it is suitable for the application, such as consultation with a qualified materials selection engineer to check all parameters for material suitability (temperature, pH, etc.). One must also determine if the material is readily available in the marketplace, or what alternative materials can be utilized, if they can be welded, fabricated, and finished to the required specifications, and that the material can be maintained effectively.

For information regarding the fabrication of vessels, contact Brian Uhlenkamp at DCI, Inc. For information regarding tubing and fittings, contact Ken Kimbrel at CSI, and for information regarding tank bottom valves or ASEPCONNECTs, contact Mark Embury at ASEPCO.

Brian Uhlenkamp has worked in the vessel fabrication industry for over 20 years. The last 10 years he has been working with DCI in the area of product development. Ken Kimbrel has over 30 years of experience in process piping/tubing and metallurgy. He currently works for CSI in product development and sales.

In this article, we offer some philosophical observations on “mission-critical” components that we hope will serve as a guide for managing your manufacturing future. They could change your ideas about the characteristics you should demand of aseptic component makers. They might also give you a concrete idea of what you can count on from ASEPCO.

ASEPCO has already structured itself and its valves, mixers, and ASEPCONNECT close-connects, for mission-critical applications. And we’re now prepared to live up to an even tighter spec so that we can become your preferred provider of aseptic processing equipment. We’re also about to make you a promise, so read on.

For many of you, mission-critical conjures up the gold foil-covered shields found on space satellites or “mil spec” parts found in an F-16. But in truth, you’re using mission-critical components in your facility right now. The question is, were they designed to live up to your demands?

After all, the combination of sheer product value and risk of product compromise through contamination definitely make for a “get-it-right-the-first-time” processing mentality in our industry.

But does your equipment help you to achieve this, or does it more often get in your way?

This is what ASEPCO believes mission-critical means when it comes to aseptic components:

“…the extremely consistent performance and delivery of vital components in an application where downtime and product loss attributable to equipment failure cannot be tolerated.”

So, just what should your equipment do, if it’s designed for mission-critical use? The list below summarizes the mission-critical characteristics of ASEPCO valves. We offer these as a measuring stick against which other manufacturers can be compared. All items on this list are already a part of how we deliver equipment to you. The bold entry is a new addition to our list.

• Proper operation should require little attention to detail.
• It should be difficult to make the components fail (at ASEPCO we call this “bomb proofed” design).
• The basic design should require very little training—and no tools—for operation.
• Components should be very easily and quickly validated.
• CIP/SIP cycle times should be short.
• Manufacturing should meet world class standards.
• Manufacturing methods should eliminate defects inherent in the production process (such as pitting or cracks found in cast valves versus valves machined from barstock).
• Traceability (i.e., serial #s and material certificates) should be provided with your shipment for all product contact surfaces.
• Conformance to relevant U.S. and international standards (ASME BPE, CE-PED, CRN, USP, etc.).
• Simple maintenance instructions sent with every order.
• Delivery is fast, accurate, and on time.
• Demonstrated commitment to the U.S. market by offshore companies, which should include:
  1. Documentation to U.S. standards
  2. U.S. based technical support and manufacturing (to ensure long-term support of the product and standard materials)

Okay, here’s an additional mission-critical item we’re prepared to offer you. We’ve added DELIVERY to this list. We’ve restructured ASEPCO to deliver more equipment, faster, and with greater predictability. In fact, over the past six months we have averaged 4.5 weeks for our standard 316L valve deliveries, 8.2 weeks for specialty materials like C-22 and duplex 2205, 4.2 weeks for our ASEPCONNECT connectors, and 10.4 weeks for our Polymixers™. You’ve come to expect the very highest quality from ASEPCO products. That’s why our valves, connectors, and mixers are flying off the shelves. Now you can add fast delivery to that list of what you can expect from us.

In any biopharmaceutical application, material specifications are a critical component to the success of the project. Engineering firms specify the materials that must be used based on the process conditions those materials will be exposed to during processing. Vendors like ASEPCO provide products that conform to these specifications. When the products are received, end users must verify that the products conform to the specifications. Positive Material Identification (PMI) is one of the non-destructive techniques used verify material conformance.

At Sturgill Welding & Code Consulting, we find that PMI results are sometimes misinterpreted, which can cause project delays and other issues. So, we thought it might be useful to briefly discuss what PMI is, the equipment that is used to perform PMI, and how to evaluate the results produced by the testing equipment.

Various techniques are used to determine the chemical composition of metallic engineering alloys, ranging from laboratory methods that can identify all of the elements (including interstitial elements such as carbon and sulfur) to employing portable units that can determine only a limited number of alloying elements. Positive Material Identification (PMI) is one of these techniques.

For this discussion, we focus on the portable hand-held units commonly used in the biopharmaceutical industry for alloy verification. These units can operate in two modes: They can either provide data as a discreet list of alloying elements and their amounts, or they can identify an alloy by comparing the compositional data obtained against a list of alloys whose partial nominal compositions are stored in the unit’s memory. This report explains that the most reasonable way to use PMI data is to compare both the discreet list of alloying elements determined by PMI and the interstitial elements listed on the MTR with the requirements of the material specification to which the material was purchased.

Background

The raw data collected by PMI units is the X-ray spectra that plots the intensity of outer shell electron decay as a function of the characteristic energy level (wavelength) for each element detected. PMI units convert these spectra to lists of alloying elements and their amounts. These units usually have built-in alloy grade libraries that list partial composition ranges for many commercial alloys.

A PMI unit identifies an alloy based upon the alloy library in the PMI unit’s memory. This data is based on a wide range of specifications and sources including American Society for Testing and Materials (ASTM), Society for Automotive Engineers (SAE), American Iron and Steel Institute (AISI), and trademarked manufacturers such as Haynes, Carpenter, and Allegheny Ludlum (which make and patent certain alloys). This data might be unrelated to the specifications to which the material or equipment in question was ordered. In addition, the PMI unit might identify a material as a specific alloy if its composition is close to that of an alloy in the PMI unit’s library, not because it actually meets a set of criteria.

Portable X-ray fluorescence (XRF) technology cannot detect elements whose atomic numbers are less than 22 (which corresponds to titanium), so important elements such as carbon, sulfur, silicon, and phosphorus cannot be detected. However, material specifications that govern materials of construction for our industry specify ranges for these elements. As a result, PMI data, by definition, cannot be used to determine an exact match to any ASTM or ASME material specification.

For this reason, a PMI unit’s display reading that an alloy “matches” a 316 stainless steel composition cannot be used as proof that that alloy meets a material specification requirement. Only the material specification or and alloy grade requirement on the contract document is enforceable, not the PMI unit’s statement that an alloy is a “match.”

Applicable Standards and Specifications

Vendors and equipment fabricators build equipment based on written instructions from engineering firms or end users. These instructions are usually in the form of a purchase order or a bill of materials (BOM), which is included in the drawing package of requirements for a piece of equipment. The construction material is identified by two pieces of information: the material specification and the alloy grade or designation.

Material Specifications

The material specification is one of a number of common ASTM, ASME, or foreign specifications that list different alloy grades of a single product form or for a single intended use. Typical specifications include:

• A240/SA-240 for plate, sheet, and strip for pressure vessels (heads and shells of vessels are usually made from plate products produced to this specification)
• A249/SA-249 for welded austenitic steel heat exchanger tubing
• A213/SA-213 for seamless austenitic steel heat exchanger tubing
• A484/SA-484 for stainless steel bars, billets, and forgings
• A351/SA-351 for stainless steel castings for pressure containing parts
• A182/SA-182 for forged or rolled alloy steel pipe flanges, forged fittings, and valves and parts for high-temperature service

Each of these specifications lists a number of alloy grades. In fact, each has a listing for the chemical compositional requirements for 316L stainless steel. This list of elements and their compositional ranges is identical in some specifications, but might have different ranges for certain elements in others. So, to evaluate any set of PMI readings, both the alloy grade and the material specification are needed for every piece tested.

Alloy Grade/Designation

The alloy grade is an informal description that can be manufacturer specific, such as Hastelloy C276, or it can be more generic, using the Unified Numbering System (UNS) for Alloy 276, UNS N10276. The UNS number is the industry standard for alloy grade or designation.

As an example, AL-6XN is a 6% molybdenum alloy manufactured by Allegheny Ludlum. Originally, this alloy was made and patented by Allegheny Ludlum, and the specific alloy name, AL-6XN, is a registered trademark of Allegheny Ludlum. The patent on this alloy has expired and a number of manufacturers now make this alloy. As a result, the more generic name for this alloy is UNS N08367. So, AL-6XN is not an alloy grade; it is a trade name and specifies UNS N08367 made by Allegheny Ludlum.

PMI Accuracy

The accuracy of compositional data produced by PMI units must be evaluated prior to comparing the data to any standard for acceptance. One factor that affects accuracy is exposure time; that is, the time that the detector in the PMI unit is receiving energy from the decay of the excited electrons in the material The typical minimum exposure time for accurate readings is 30 seconds, and the longer the exposure time, the more accurate the reading. Some of the older gamma-ray source units require the operator to depress and hold the trigger manually for the full exposure time to keep the shutter open. Inaccurate readings obtained on the older units can be due to single pulse depressions of the trigger, which result in only momentary X-ray exposure, and, as a result, incomplete data. The newer units automatically hold the shutter open for the necessary exposure time without the operator having to hold the trigger.

In addition, the data output usually has a header of “Element +/- Prec.” This reflects the accuracy tolerance in wt. % of the reading indicated on the display of the PMI unit. If the reading is 58.21 +/- 0.86, the real reading is anywhere between 57.35 and 59.07. As a result, this “precision tolerance” must be added to and subtracted from the displayed value to see if the range produced generates a value within the acceptance range in the appropriate ASTM material specification.

Product Analysis Tolerance

If the PMI unit reports a range outside the compositional range listed in the appropriate material specification, do not automatically reject the material. Domestic material specifications list compositional ranges for the elements in a given alloy. The material purchaser is allowed to perform a product analysis to verify the identity of the furnished material; PMI is a form of this product analysis. The material specification lists the tolerance that can be applied to such product analysis, or states that the product tolerances are found in some other material specification, referred to in this report as “secondary specifications.” This is the amount by which the product analysis, when requested by the purchaser, can be either over the maximum or under the minimum limit and still be acceptable. These tolerances are a function of the nominal amount of the specific alloying element in the material and increase as the amount of the element in the alloy increases. For instance, for nominal specified molybdenum contents between 7 – 15 wt. %, the product analysis tolerance is +/- 0.15 wt. % (in some specifications). So, for UNS N06022, having a specified molybdenum range of 12.5 to 14.5 wt. %, the product analysis tolerance of +/- 0.15 wt. % results in an acceptable range for PMI data for molybdenum of 12.35 to 14.65 wt. %.

For product analysis tolerances, ASTM B880 is the secondary specification found in several ASTM specifications for nickel-based products. ASTM B751 contains the product analysis tolerances for nickel-based tubing, including AL-6XN as listed in ASTM B676.

For the purposes of evaluating PMI data, these product analysis tolerances, along with the precision tolerance of the PMI unit being used, must be considered together to determine acceptability of the PMI data.

Meeting the Molybdenum Range

Bear in mind that the amount of molybdenum present in N06022 (or any other molybdenum-bearing alloy) will not be in the middle of the specification range of 12.5 – 14.5 wt. % for this alloy. To minimize the cost of the alloy, the amount added by producers is typically the smallest amount required to meet the specification range (12.50 to 12.70 wt. %). As a result, the PMI data generated on these “higher alloys” can result in some data that is under the low limit for the important and expensive alloying elements, such as molybdenum or nickel. This underscores the importance of understanding how to use the product analysis tolerance values in conjunction with PMI precision to evaluate marginal alloy PMI data. In addition, because the hand-held PMI units cannot determine carbon, silicon, sulfur, and phosphorus, PMI data must be used with the data on the MTR to determine compliance to a material specification and to the alloy requirements of the user specification.

Summary

Sturgill Welding & Code Consulting recommends that PMI data be used in conjunction with the interstitial element data on the MTR to determine material compliance to a specification. Those operating the PMI unit must be trained individuals who ensure that each reading is the result of a full exposure cycle. Operators must apply the appropriate product analysis tolerance and precision tolerance to each reading before evaluation. Remeasuring to obtain an acceptable or unacceptable result is NOT permissible for acquiring and evaluating PMI data.

ASEPCO defines mission-critical-level aseptic components as those that provide extremely consistent performance and delivery of vital functionality in an application where downtime and product loss attributable to equipment failure cannot be tolerated.

So, what should your equipment be able to do if it’s designed for mission-critical use? We offer the following list of mission-critical characteristics as a measuring stick against which to evaluate all your aseptic components:

• Proper operation is easy to implement.
• It is difficult to make components fail (at ASEPCO we call this “bomb-proofed” design).
• The basic design requires very little training for operation.
• Components are easily and quickly validated.
• CIP/SIP cycle times are short.
• Component manufacturing methods eliminate defects inherent in the production process (such as the pits and cracks found in cast valves vs. those manufactured from bar stock).
• All components conform to relevant manufacturing standards (such as ANSI, ASME, BPE, CE, and CFR).
• Traceability is provided (certificates on steel, fittings, and diaphragms, and heat numbers on welded sub-components).
• Maintenance instructions are simple and are sent with every order.
• Delivery is fast, accurate, and on time.

At ASEPCO, we have structured our manufacturing processes and designed our components (valves, mixers, vessel connectors, etc.) to meet these mission-critical component characteristics. And, we hope that by promising to comply with this list, you will make us your preferred provider of aseptic processing components.

Over the years, you’ve come to expect the highest design quality from ASEPCO. That’s why our tank valves are some of the most frequently used valves in critical applications. Now you can add inline valves, vessel connectors, and magnetic mixers to that list.

“When issuing a performance specification for a bottom mounted magnetic mixer, what are the critical pieces of information required by the mixer vendor to facilitate the correct sizing and end performance of the mixer?”

This is an excellent question and it is often overlooked in the rush to get mixers quoted and then ordered. It is also missed because the mixer vendor is often not in direct contact with the engineer who is requesting the mixer. The most significant reason this is so important is, if you undersize a magnetic mixer (and many are undersized) you only have three options for correcting the problem:

1. Live with less than adequate mixing.
2. Supplement or replace the bottom magnetic mixer with a top-mount mixer.
3. Cut out the mixer and replace it with a larger unit.

Let’s take a look at each of these options individually to understand why they may not be adequate solutions. Then we’ll explore how giving as much information about your mixing application as possible is vitally important to you successfully implementing your process:

1. Can you really live with less than adequate mixing? Probably not. At best it may be sufficient to get the job done, but only in the same way as using duct tape to fix a leaking radiator hose: it’ll work, but it could get real ugly, real fast. How could it get ugly? Well, if you undersize your mixer it can cause problems such as, increased processing time (read as: more co$t), or reduced yield (you guessed it, more co$t).
2. How about replacing or supplementing the bottom mount magnetic mixer with a top mount mixer? If you’ve already built the vessel this may be an option. The question you have to ask is, “Can we add a top mount without modifying the vessel?” Unless you included a mounting option for a top mount mixer when you designed and built your vessel, you’re going to end up with the potential problem of having to recertify the vessel after you modify it. This, of course, is going to mean a delay in implementation as well as an increased cost. Even if you haven’t built the vessel yet, a change at this stage increases costs and can delay the project as well.
3. What about cutting out and replacing the magnetic mixer with a properly sized magnetic mixer? This has the same problems as the prior solution. When you cut into a completed pressure vessel, you are going to have to recertify that vessel, often at great expense. Additionally, if you have to install a larger size mixer you may not have sufficient space to do so.

   

So, what are the critical pieces of information to give to your mixer vendor to avoid any of these choices? Keep in mind that the more information you supply, the more efficient and better performing your mixer is in your process. You can supply the information in two steps:

At the beginning of your design process, you probably only need a ballpark price for your mixer and an idea of what it should look like. In this case you can start with a minimal amount of information. Your mixer vendor should be able to give you a budgetary price if you supply the following information:

1. Vessel size – 50L, 250L, 1000L, etc.
2. Agitation level – mild, moderate, vigorous, violent
3. Process type – blending, heat transfer, powder addition, fermentation, cell culture, suspension, etc.
4. Specific Gravity – 1, 1.2, or 1.4 are common

When your vendor has this information they should be able to give you a price and model. The next step is where it gets interesting. This is where you want to give more detailed information to your mixer vendor. In addition to the information above, there are other critical pieces of information you should tell your vendor mixer. Here is a partial list:

Vessel:

1. Vessel dimensions (e.g., side height, wall thickness)
2. Volume – vessel and media
3. pH level of process fluid and cleaning solution (maximum and minimum)
4. Jacket surface area, heat coefficient

Process:

1. Process Type (e.g., suspension, blending, heat transfer)
2. Media type (e.g., Newtonian)
3. Process temperature
4. Process pressure
5. Viscosity of the process media
6. Specific gravity of the process media
7. Are there solids?
8. Particle size of the solids – average and largest
9. Solubility
10. Gas flow velocity

Environment:

Is it a hazardous environment?

This is by no means, a complete list, and depending on your process other information may be needed. The more of these questions you can answer, the better your mixer suits your process. Often, your mixer vendor makes this easy by supplying a questionnaire that lists the information you should supply. You can see our example of this here: http://www.asepco.com/pages/products/mixers/mixers.php. Or you can supply your engineering datasheet that should cover the pertinent information.

When your vendor has the detailed information he can more precisely verify what mixer is best suited to your particular process. There are several ways to achieve this. We use a mathematically based program called Visimix™. This allows us to quickly determine the right mixer for any given process. It also allows us to quickly try different variations from impeller type to scale-up, if that is required. [see sidebar: mixing calculations]

The key here is that the more information you supply the better the results for your process. The last thing you want is a mixer installed in your vessel that leads to increases in production time and/or increases in cost. Working closely with your mixer vendor gives you the most effective and efficient mixer for your process, both in terms of cost and performance.