Stainless Steel Finishes: What Makes A Weld Sanitary?
In today’s post, we are going to focus on welding and what makes a weld sanitary in today’s sanitary (hygienic) processing facilities.
To start, let’s look at a very general definition and overview of welding. Welding is the joining process in which two (or more) parts are coalesced at their contacting surfaces by application of heat and/or pressure. Welding is achieved by two basic categories; fusion welding and solid state welding. Fusion welding is accomplished by melting the two parts to be joined, and in some cases, adding a filler metal to the joint. Examples of fusion welding processes include arc welding, resistance welding, and laser beam welding. Solid state welding involves the application of heat and/or pressure but no melting of base metals occurs and no filler metal is added. Some examples include forge welding, diffusion welding, and friction welding.
The American Welding Society AWS D18 Committee was formed by the request of the 3A Sanitary Standards Committee for help in outlining welding standards for use in the manufacture and construction of dairy and food product processing plants. Within the AWS D18.1/D18 Specification is where it is defined that all welds for austenitic stainless steel tube and pipe are to be done by the gas tungsten arc welding (GTAW) process (also known as the tungsten inert gas, or TIG, process). This process uses a non-consumable tungsten electrode along with an inert gas (argon or helium) for arc shielding. The purpose of arc shielding is because at high temperatures, metals are chemically reactive to the oxygen, nitrogen, and hydrogen that is present in air, and thus without a shielding gas the mechanical properties of the joint are subject to oxidation. So the advantage of the GTAW welding process is that it produces high quality welds with little or no post-weld cleaning.
GTAW Welding
According to the AWS D18.1/D18 Specification, welds are to be fully penetrated to the ID to prevent the formation of crevices which could entrap product and lead to contamination. In order to determine acceptable oxidation levels, the AWS D18.2/D18 Specification provides a visual examination guide to aid in the inspection of color in the heat affected zone (HAZ) for welds in piping systems. The heat affected zone is the area of base metal that has experience temperatures below melting point, but high enough to cause changes in the properties and microstructure of the metal.
AWS Weld Discoloration & Acceptance Criteria Scale
As the demands of the bioprocess industry for clean, smooth product contact surfaces increased, advances in process piping technology and equipment fabrication technology have followed. Orbital welding was developed as an automated process to address the risk of operator error in GTAW processes. Orbital welding offers the advantage of a computer controlled system that combines arc current, feed and speed to allow the ‘orbital weld head’ to travel around the tube in a steady manner in order to produce consistent and repeatable weld profiles. Hooray for automation.
The 3A Standard was extensively used by the pharmaceutical food and dairy industries but with the emerging bioprocess industry, higher standards were needed for equipment design that would be both cleanable and sterilizable. The ASME published the first edition of the ASME Bioprocessing Equipment Standard in 1997 (BPE-97) to help address this need. Part MJ (Materials Joining) of the ASME BPE Standard requires that the weld criteria of ASME B31.3 – Process Piping be met for acceptable metallic materials. While ASME B31.3 prohibits weld discontinuities such as cracks, voids, porosity, lack-of fusion, and incomplete penetration, the ASME BPE Standard also provides visual examination acceptance criteria to determine the hygienic condition of the piping system. It should be noted that the BPE standard specifies orbital welding as the preferred joining technology for bioprocess tubing, and that manual welding may be performed with owner/user and contactor agreement.
Acceptable and Unacceptable Weld Profiles
Hopefully this blog has provided a good overview of the welding practices used in our industry and what criteria and standards define practices to be sanitary. For over 50 years, Holland Applied Technologies has built a reputation as being one of the highest quality sanitary stainless steel fabricators in the US. All sanitary welding is done using cryogenic Argon and our orbital welders have automated Oxygen sensing systems. If you have a custom sanitary process piping application, call us at (800) 800-8464. We can help you with your design and work with you to come up with the most cost effective, high quality solution for your application.
Sanitary Surface Finish Chart
Below is a comprehensive graphic for surface finishes that we hope you find useful. The Surface Roughness Conversion Chart will help to convert surface finish between selected industry standard units. The Common Names table lists some common surface finish names and how they are defined by their Ra number. Lastly, the Sanitary & BPE Surface Finishes table defines the surface finish requirements as established by the ASME BPE 2016 Standard. This table is also useful in that it relates surface finish codes from various manufacturers to the ASME BPE Standard.
N = New ISO (Grade) Scale numbers
Ra = Roughness (average), measured in microinches (µin) or micrometers (µm)
RMS = Root Mean square, microinches (µin)
Stainless Steel Finishes: Know What You Need
This blog is the first in a series of posts about sanitary surface finishes. In this post, we will cover surface finishes as they pertain primarily to sheet metal and subsequent posts will provide further detail on surface finish standards for fluid process components.
How is a specific level of finish defined and how can that level of finishing be achieved? For our industry, surface finishes are a standard set by regulatory agencies (3A, ASME BPE, etc.) and manufacturers who specify a certain level of finishing on processing equipment in order to ensure cleanability and sanitation. These bodies require sanitary finishes to have a minimum Ra (roughness average) typically measured in microinches (µin) or micrometers (µm). But what is considered clean in one application will likely be different from the surface finish requirement in another application. For example, the 3A requirement is generally equivalent to, or smoother than a 32 Ra (microinch) while the ASME BPE standard categorizes several different surface finishes ranging from 0 to 32 Ra through the means of mechanical polishing and electropolishing.
You may know what type of finish you need for your application, but if you want to really understand the various terms and definitions used for stainless steel surface finishes then you can read about them here where we define important terms such as Ra, roughness, and grit.
Surface finishes can be enhanced through various means of mechanical and chemical treatments. In our industry we typically see these treatments achieved via the following methods.
Sanitary Tubing with an Electropolish Finish
Mill Finish is the baseline finish used for comparison. Mill finishes will have a dull or matte non-uniform appearance with a Ra of at least 100 µin. This finish does not meet sanitary processing finishing requirements.
2B Mill Finish will have a more reflective appearance—almost like a cloudy mirror. This finish is more common in industrial, chemical and food applications and will have a large range of Ra values.
No. 4 Finish will have a Ra of 29 to 40 microinches. Although it can be found in clean rooms and in food processing equipment, it is not compliant for 3A standards (32 Ra or less).
No. 4A Finish is similar to the no. 4 finish in that is characterized by short, polished brush lines but uses a finer grit polish. This finish is required to meet the basic 3A standards and will have a Ra of 18 to 31 microinches.
Bead blasting uses a fine bead material, such as glass, at a high pressure to provide a certain level of finish. Ra values are typically greater than 45 Ra, depending on the blasting process.
Passivation means removing the excess iron or iron compounds from the surface of the metal using an acid solution (nitric or citric acid). Removing these impurities allows the formation of an oxide layer that protects the rest of the steel from corrosion. Passivation has little effect on Ra values.
Electropolishing is an electrochemical process where the surface metal is dissolved and the embedded contaminants are removed. This creates a “smooth” mirror finish and can result in increased smoothness.
As you can see, there are many manufacturing and chemical processes used to achieve various levels of finishes. When selecting equipment with higher-end finishes, often times we see processors elect to exceed the minimal standards set by regulatory agencies in order decrease bacteria risk. Hopefully this post proves as a useful reference when weighing the various stainless steel finishes on sanitary equipment.
ASME BPE – More Than Just a Standard for Fittings
Many people have heard the term ‘ASME BPE’ when buying fittings and tubing for the Biotech and Pharmaceutical industry. If you haven’t heard of ASME BPE, or are unfamiliar with this standard, then I’d like to refer you to one of our past blogs where we give a general overview of ASME BPE, what they do, and why it is so important to our industry.
The ASME BPE Standard is probably most known for having specifications on dimensions and surface finish for fittings and tubing. We’ve highlighted some of the key differences between ASME BPE tubing and standard sanitary tubing before, which you can read about here.
Today, however, we are going to give a general overview of just what kind of equipment and design standards the ASME BPE standard covers.
The current ASME BPE Standard was published in 2016 and has an extensive chapter on Systems Design (Chapter 2, Part SD). The purpose of this subcommittee is to establish design guidelines applicable to bioprocessing equipment, components, assemblies, and systems. This chapter contains information regarding, but not limited to, the items and topics listed below.
- Steam-In-Place (SIP). ASME BPE states that ‘equipment parts and components that are subjected to SIP should be designed and constructed to withstand continuous exposure to saturated steam at a minimum temperature of 266 F for a duration of at least 100 hr under continuous steady-state conditions’.
- Drainability. The systems ability to facilitate drainage, mainly achieved by gravity.
- Connections, Fittings, and Piping. These are the common process components of hygienic piping systems which you are likely to be most familiar with. Dead legs are discussed within this topic.
- Hose Assemblies. Design and installation guidelines for hygienic hose assemblies (both their flexible element and the end connections).
- Pumps. System application such as the cleanability, drainability, and installation of diaphragm pumps, centrifugal pumps, positive displacement pumps, and rotary lobe pumps.
- Vessels. This section defines the requirements that are to be met in the design, fabrication, and supply of both pressurized and unpressurized biopharmaceutical vessels.
- Agitators and Mixers. Design, cleanability, material construction, etc. of process contact surfaces of these equipment as well as their sub-components such as shafts and keyways, impellers, bearings, and mechanical seals.
- Heat Exchangers. These include plate-and-frame heat exchangers and shell & tube heat exchangers. Design for cleaning/steaming and fabrication techniques are discussed by the ASME BPE standard.
- Transfer Panels. As defined by ASME BPE, a transfer panel is ‘a panel to which process and/or utilities are piped that mechanically precludes erroneous cross connections’.
- Filters. Housing design of filters and the testing and validation of the cartridge according to ASME BPE Code 7.
- Steam Sterilizers/Autoclaves. This section defines the design and cleaning requirements of autoclaves that are used in bioprocessing.
Chapter 3 covers the materials that are considered applicable for use in hygienic service, both for Metallic Materials (Part MM) and Polymers and other nonmetallic materials (Part PM).
Chapter 4 outlines Process Components. The Dimensions and Tolerances section (Part DT) provides the guidelines for automatic weld ends for 316L-type alloys and sanitary clamp gaskets. Instruments for level, pressure, and temperature are addressed in the Process Instrumentation section (Part PI) of the Standard. Conductivity sensors, flowmeters and sight glass information can also be found under the Process Instrumentation section. Sealing Components (Part SG) provides the design and performance requirements for sealing components such as mechanical seals, O-rings, and diaphragms for valves.
Chapter 5 highlights Fabrication, Assembly, and Erection. Here you can find the requirements for Materials Joining (Part MJ). The Materials Joining section has color charts and vast information on welding/joining of materials, for both metallic and polymeric materials. Process contact surface finish requirements are covered in Part SF.
Chapter 6 establishes the requirements for obtaining a Certificate of Authorization and the ASME Certification Mark.
The Mandatory Appendix provides guidance to ASME BPE Standard users who wish to submit requests for revisions/additions to the BPE Standard, requests for Code Cases, and requests for interpretation of the BPE Standard.
Finally, the Non-Mandatory Appendix contains helpful information on Rouge and Passivation procedures. It contains information on Ferrite, Corrosion Testing and Electropolishing. This section also contains examples of incoming inspection material examination data sheets used by Quality Control and Mechanical Contracting personnel.
Holland Applied Technologies personnel work with ASME BPE equipment each day. In fact, our own Troy Hobick sits on many of the BPE subcommittees. For any questions regarding ASME BPE equipment please contact us at 800-800-8464 or our website www.hollandapt.com. Or, if you’d like to read the ASME BPE Standard for yourself, it can be found at asme.org or you can call 1.800.THE.ASME.
Guest Post- Material Trends for High Purity & Sanitary Applications
By: Ken Kimbrel- Special Alloys Product Manager, VNE Corporation
For almost 60 years, Holland Applied Technologies has been providing customers with the best high purity process products in the industry. Today, we’re excited to share our first guest post, highlighting our newest sanitary fitting product offering, as well as providing an excellent overview of what makes a material corrosion resistant. Enjoy!
For several years stainless steel has been the workhorse processors have used in tough corrosive environments. For the most part, it has performed well. In recent years, however, in many new installations or even repairs to existing process lines, today’s stainless steel doesn’t perform as well in the same application as stainless steel of years past. Additionally, with the advent of newer buffer solutions in the pharmaceutical industry we are experiencing higher than ever chloride levels which attack stainless steel causing pitting and crevice corrosion.
As with all industries, imports, competitive markets and technological advances have enabled and even forced steel manufacturers to become more competitive in the steel making process. The most significant of these advancements impacting the steel industry was realized nearly 40 years ago with the introduction of argon-oxygen-decarburization (AOD) refining. The use of AOD allows the extensive use of scrap metal. In fact, some heats are nearly all remelted scrap metal. The only disadvantage is a continual build-up of non-specified tramp elements like copper, boron and calcium. The AOD process allows precise gas manipulation to achieve the desired result and refines stainless steel by gradually replacing oxygen by means of blowing argon through the molten metal to eliminate impurities.
The American Society for Testing and Materials (ASTM) specification shows the chemical composition of any alloy in ranges with a minimum and maximum allowable limit to meet the requirements for the specific alloy. For example, the chemical composition for 316L stainless is as follows.
| 316L | Chromium | Nickel | Molybdenum | Carbon | Iron |
| Minimum | 16% | 10% | 2% | ||
| Maximum | 18% | 14% | 3% | 0.035% | Balance |
Today, when alloying 316L stainless steel the AOD process allows precise control of alloying elements, enabling the mills to make a product to an exact chemical composition. This also allows the elements to be controlled to the minimum range allowed for the specification. Compared to decades past when alloying 316L, the amounts of alloying elements were added with little control and often pushed or exceeded the upper limits of the maximum requirements. The resulting steel was a product with corrosion resistant properties superior to 316L stainless steel that is manufactured by using today’s methods. Today we see melts of steel meet the requirements of the specification on the low end, resulting in the overall mean corrosion resistance of the material trending downward. If a higher alloyed, but within-grade 316L composition is desired, it typically requires a special order of a full heat of material. Due to the cost or purchasing a complete melt, it is often more practical to specify a more corrosion resistant grade such as 904L, duplex stainless steel or a 6% Mo grade to obtain small quantities than to special order an enhanced 316L composition.
Determining the corrosion resistance of any alloy is always a challenging task. Varying service environments, aggressive cleaning and sterilization practices, and even multiple product forms of materials used in equipment fabrication can have a negative impact on corrosion resistance of materials. Because of these ever-changing conditions, the best corrosion data available is often the service history of the system itself. When choosing the correct materials of construction, it is recommended that a qualified Materials Engineer be consulted for evaluating the solutions, compounds and operating conditions the system will be exposed to. The most widely accepted materials of construction beyond 316L stainless steel in high purity and sanitary applications are the super-austenitic, nickel, and duplex alloys. These alloys can vary in their chemical make-up resulting in different levels of performance in certain corrosive or acidic environments. Table MM-2.1-1 in the current edition of the ASME BPE Standard identifies materials acceptable for use in the Biopharmaceutical industries that have been proven they can meet the requirements of welding and surface finishes listed within the Standard. Of these materials listed, this paper is going focus on Type 316L austenitic, superaustenitic stainless steels 904L, Ultra6XN, AL-6XN® and nickel alloys C-22® and Alloy 22.
ASTM Composition of Wrought Steels
| UNS | Alloy | EN | C | Mn* | Cr | Ni | Mo | N* | Cu | PREN |
| S31603 | 316L | 1.4404 | 0.030 | 2.00 | 16.00-18.00 | 10.00-14.00 | 2.00-3.00 | 0.10 | … | 24 |
| N08904 | 904L | 1.4539 | 0.02 | 2.00 | 19.0-23.0 | 23.9-28.0 | 4.0-5.0 | – | 1.0-2.0 | 36 |
| N08367 N08926 | Ultra 6xn | 1.4529 | 0.02 | 2.00 | 19.0-21.0 | 24.0-26.0 | 6.0-7.0 | 0.15-0.25 | 0.75 | 45 |
| AL-6XN® | AL-6XN® | – | 0.03 | 2.00 | 20.0-22.0 | 23.5-25.5 | 6.0-7.0 | 0.18-0.25 | 0.75 | 45.2 |
| N06022 | C-22® | 2.4602 | 0.01 | 22 | 56 | 13 | 0.5 | 68 | ||
| N06022 | Alloy 22 | 2.4602 | 0.015 | 22 | 56 | 13 | 0.5 | 68 |
*Maximum
Note: Sulfur is limited to 0.030 max and Phosphorous to 0.045
When comparing alloys for corrosive environments, the most important elements of the materials chemistry for corrosion resistance is Chromium, Molybdenum, Nickel and Iron. None of these listed elements alone are magical in preventing corrosion but alloyed correctly and manufactured properly, can improve corrosion resistance and the life expectancy of a high purity system.
- Chromium – Cr is a key component of stainless steel that accounts for its passive nature. Chromium significantly improves corrosion resistance when the composition contains a minimum of 10.5%. When at or above these levels, an adherent and insoluble surface film, known as the passive film, is instantaneously formed that prevents diffusion of oxygen into the surface thus prevents oxidation of the iron in 316L stainless steel. Chromium is also the weak link in stainless steel when in contact with chlorides by reacting with the chromium oxide in the passive layer to form chromium chloride, which is very soluble. This leaves a layer of iron and iron-nickel on the surface, an active film which will allow the stainless steel to corrode and the metal to be consumed.
- Molybdenum – Mo increases the resistance to localized corrosion in the forms of pitting and crevice corrosion. The higher the molybdenum content, the better the corrosion resistance to higher chloride levels by enhancing the passive film, making it stronger and helping it to re-form quickly if it is disrupted by chlorides.
- Nickel – Ni is an alloying element critical to stainless steels and results in the formation of the austenitic structure that increases strength, impact strength and toughness, while also improving resistance to oxidization and corrosion. It also increases toughness at low “cryogenic” temperatures. Nickel has no direct impact in the formation of the passive layer, but it does offer improvement in resistance to acid attack.
Another alloying element that has a positive impact and found in 316L, Ultra 6XN and AL-6XN® is Nitrogen-N, which increases the austenitic stability of stainless steels and improves yield strengths in low carbon grades of steel containing less than 0.03%. It can also enhance resistance to localized pitting and intergranular corrosion.
A guide to the corrosion resistance of alloy can be found in the calculation of its Pitting Resistance Equivalency Number (PREN). The chemical composition of the alloy along with this formula (Cr + 3.3Mo + 16N=PREN) will result in a number ranking the alloy. The higher the number, the more resistant the alloy is to localized corrosion. PREN’s can be found in the materials table above.
Those alloys containing 6% molybdenum content may require special fabrication methods beyond what is generally found in 316L stainless steel systems. However, they are common place and manufacturing practices are available to guide fabricators and suppliers. All the alloys listed in the table above are available in common sizes found in most sanitary designs and product forms such as tubing, fittings and valves.
For information regarding pricing and specifics of fabrication please contact the author.
AL-6XN® in a registered trademark of Allegheny Technologies Inc.
C-22® is a registered trademark of Haynes International Inc.
About the Author:
Ken Kimbrel is Product Manager – Special Alloys for VNE Corporation in Janesville, WI. He is responsible for specialty alloy sales, market planning, process and material evaluation in corrosive environments. He attended Tulsa Comm
Ken Kimbrel
unity College and has an extensive background in engineering, equipment manufacturing, and is a NACE International Board-Certified Corrosion Technician. His expertise includes corrosion evaluation, material selection, surface finish evaluation, and rouge remediation.
Ken is the current Chair of the ASME BPE. He has served as inaugural Chair of Subcommittee on Metallic Materials and as past Chair of the Surface Finish Subcommittee. He is a member of the Subcommittees on Accreditation, the Standards committee, Executive committee and author of several technical papers.
He is a member of the International Society for Pharmaceutical Engineering (ISPE), ASM International (ASM), the International Metallographic Society (IMS), the National Association of Corrosion Engineers (NACE).
Contact information:
E-mail: kkimbrel@vnecorp.com | Ph: 800-356-1111 | Cell: 417-827-2526
Universal Twin Screw Pump- The “Can-Do” Twin Screw
In today’s post, we wanted to focus on one Waukesha Cherry Burrell’s newest products- the Universal Twin Screw pump.
Twin screw pump technology has been around a long time, but only recently has this technology been used in sanitary pump applications. When properly applied, twin screw technology can offer compelling advantages over other types of sanitary PD pumps.
One of the first differences you’ll notice between twin screw pumps and traditional rotary lobe pumps is the axial motion twin screw pumps use to convey product through the screws. This axial type movement of product allows operation with low NPSH and virtually pulse free pumping. And by adjusting the pitch of the pump screws, twin screw pumps enable very low shear pumping and can handle solids much more gently than rotary lobe pumps
The axial pumping motion of the Waukesha Universal Twin Screw pump also enables the pumps to be run at much higher speeds- up to 3500 RPM. Higher speeds mean greater turndown, giving users the ability to use the Waukesh
The Universal Twin Screw Pump
a Universal Twin Screw pump as both a product AND CIP pump. Twin screw pumps can also handle large amounts of entrained air, making them ideal for pumping out of tanks following cleaning.
Users of Waukesha Cherry Burrell brand pumps have for years benefited from the reliability and consistency their products are known for. The Universal Twin Screw pump is no exception and runs with the same reliability Waukesha is known for, quickly making it the Universal Twin Screw the “Can Do” Twin Screw.
The Universal Twin Screw takes the reliability of twin screw pumping technology to the next level by incorporating non-galling Alloy 88 screws to run with tighter tolerances and through incidental contact by reducing the risk of damage in the event screws make contact with the pump body. Large diameter 17-4 shafts have greater strength than standard stainless steel shafts, helping to reduce vibration and extend seal life. And the 316L product contact body and cover and 304SS gear case allow the Universal Twin Screw to perform in even the most demanding conditions.
One common complaint we’ve heard at Holland about twin screw pumps over the years has been high cost of spares and low levels of support once the pumps have been deployed. Waukesha twin screw pumps are manufactured in Delevan, WI and available through the same industry leading distribution channels that have serviced and supported the high purity process industry for years. Our sales engineers have extensive twin screw experience with most brands of twin screw technology and Factory Certified Holland Service technicians are ready to service any of your twin screw pump needs.
So if you have questions about twin screw pumps or any sanitary positive displacement pump, contact a Holland Sales Engineer today.
The Universal Pump Base
Amazon has ruined the world for everyone.
Hear us out. Amazon is spoiling everyone. Thanks to Prime and other popular online web services, we want everything yesterday.
For years, Holland has focused on delivering to our customers custom solutions for their complex process problems. Your one stop shop for everything sanitary process. Our products are often made to order- sometimes making it hard to deliver yesterday.
Increasingly, the feedback we’re getting from our customers is their desire for standardization and quick turnaround. Incredible value, without sacrificing quality.
The Universal Pump Base
Some might call it, “Sanitary Process Prime”.
Well, after years of development, we are excited to announce the first of a number of steps we’re taking to deliver Sanitary Process Prime- the Universal Pump Base.
At Holland, we’re a lot of things. We build sanitary process skids, fabricate custom flow components, and even crimp hoses. But at the end of the day, we’re an industrial distribution company and a Waukesha Pump dealer. Holland Sales Engineers have been expertly deploying Waukesha’s industry leading line of positive displacement pumps- the Universal 1, 2, and now 3, for years.
After all these years, one of the things we figured out is that every Universal Pump needs a base. But the base is usually the great contributor to lead time. Well, after careful analysis of the hundreds of custom pump/base/drive assemblies we’ve built, we found we could offer a Universal style of base that would cover 70-80% sanitary PD pump applications.
The goal of the Universal Pump Base program is simple- to offer round and square tube pump bases for the U1, U2, and U3 Models 6, 15, 18, 30, 60, and 130 with incredibly quick lead times and tremendous value without sacrificing industry-renowned Holland Quality.
The Universal Pump base is available in both round and square tube designs. Fabricated at our state-of-the-art hygienic fabrication facility, both styles of base are fabricated from 304 Stainless Steel and utilize Holland designed sanitary adjustable feet and all hygienic welds. The standard design is compatible with Sterling Electric 0402A and 0602A gear boxes in TEFC, white washdown, and stainless steel. Bases can even be equipped with an upright for a Lenze AC Tech variable frequency drive, installed and wired by Holland Pump Technicians.
And best of all, with the combination of a Universal Pump Base, our on-hand Waukesha PD pump inventory, and a strategic partnership with Sterling Electric, Holland can now deliver these complete sanitary pump/base/drive assemblies- sized and applied specific to your application- in as little as five days.
For more information on all of our sanitary pump and base offerings, contact a Holland Sales Engineer today.
Waukesha Universal 2 Sanitary PD Pumps
Product Focus- The Universal 3 Positive Displacement Pump
In today’s post, we wanted to focus on one Waukesha Cherry Burrell’s newest products- the Universal 3 External Circumferential Piston (ECP) pump.
Rotary lobe or External Circumferential Piston pumps have been around for years. And for almost all of those years, Waukesha Cherry-Burrell, an SPX company, has been the industry leader in sanitary ECP Pumps. Starting with the Universal 1, and furthered with the Universal 2 series of PD pump, Waukesha ECP pumps move fluid by drawing it in to the pump head and through two counter-rotating pistons. These pistons, or rotors, sweep along the outside of the pump body and turn at constant velocity.
The shape of the rotors and cavities not only moves the fluid, but deliver a constant volume per unit time for any rotor position. And because all Waukesha pumps use a non-galling Alloy 88 rotor, all Waukesha Universal Pumps have exceptionally tight tolerances and near perfect efficiency with fluids over ~300 CPS.
If you’ve been following our blog, you know we use Waukesha PD pumps across almost every sanitary pumping application. Their simple and robust design allows them to handle both low and high viscosity fluids and delivery metered flow at pressures of up to 500 PSI. They run across a range of speeds, enabling low shear pumping and handling of particulate. The Universal 1 pumps can be easily taken apart and cleaned out of place, while the Universal 2 series of pump is designed to be cleaned in place.
But that’s enough about the Universal 1 and 2 pump. Let’s talk about the latest and greatest- the Universal 3 pump. Optimized for the most grueling of sanitary positive displacement pump applications, the Universal 3 features a front loading seal desig
n making repair and maintenance a breeze. Have you ever tried to pull the body off a U2 220 that’s connected in line to inspect the seal for damage? It’s a pain in the ass- to say the least.
The new Universal 3 also combines a few other features of the legacy U1 and U2. Like the U2, the Universal 3 is CIP capable standard. The pump body has internal flats that allow it to free drain when the ports are oriented in the vertical. A new cover design also enables free draining on the horizontal or vertical port positions.
Also like the Universal 2, the Universal 3 comes standard with a single mechanical seal with options to convert to a double mechanical seal with flush. And like the Universal 1, the Universal 3 is available with both O ring and lip seals as well, making it ideal for difficult chocolate or confectionary applications.
And while the Universal 3 does come from the same core platform as the U1 and U2, it also integrates years of product research and development, making it the most robust PD pump ever built. The U3 can handle differential pressures of up to 500 PSI and is rated for fluid temperatures up to 300 F. The U3, similar to the U2, has a special rotor nut designed for extended service without loosening. The new pump shafts are shorter and user larger diameter 17-4PH, reducing overhung loads and improving shaft alignment. This decreases seal and bearing wear, extending pump life. The Universal 3 also comes standard with a 304SS gear case.
Dimensionally, the U3 is almost identical to the U1 and U2, allowing drop in replacement of current pumps and cover the same hydraulic range as the U1 and U2. The new U3 is compatible with Holland’s Universal Pump base and Holland Sales Engineers can expertly apply and deliver a U3 for you application in as little as 10 days.
So if you have questions about the new U3 or any sanitary ECP pump, contact a Holland Sales Engineer today.
Holland Applied Technologies- An Overview
At Holland, we focus on Quality in everything we do. Check out our new Overview Video to see what Holland Quality means.
BPOG Best Practice Guidelines for Mitigating Risk used in Biopharmaceutical Manufacturing
Recently, BPOG (Biophorum Operations Group) has published a guide that relates to mitigating risk in bio manufacturing processes when using single use systems components. A key aspect of the risk mitigation strategy is to consider the potential for chemical entities to migrate from the single use component material into the drug product. Suppliers could aid drug manufacturers with their risk mitigation strategies by generating extractables data on their single use materials. Extractables are typically ‘worst case’ indicators of potential leachables and provide a drug manufacturer with useful information on how to approach future leachables studies.
Key definitions to understand are listed below:
Extractables chemical entities that are able to be extracted from a component of a process system into a solvent under controlled conditions which are usually more aggressive than the normal operating conditions
Leachable’s chemical entities which come from single-use system components that migrate into the drug product during normal use. The single use system consumable qualification process must demonstrate that processing components do not impact the quality of the drug product.
It is important to understand that the product quality should be maintained throughout the drug product lifecycle to ensure that the attributes deemed important to the quality of the drug product are consistent with those evaluated during clinical studies.
One aspect detailed by BPOG and other industry bodies is how to perform risk evaluation. Risk evaluation is based on assessing the risk to patient safety, product impact manufacturing and regulatory approval. The regulations for drug manufacturers specifically detail that the equipment used in manufacturing of the drug substance shall be constructed so that the surfaces that contact the process material or drug product shall not be, reactive, additive or absorptive.
Risk assessment can be focused on either testing of every single use system component or by taking a risk-based approach where only critical single use system components are tested. The approach taken can be determined by considering the following key attributes
- Distance of the single use component to the final drug product or API
- Process temperature
- Process time
- Process fluid interaction
- Dilution effects
If you have additional questions about extractables, leachables, or any single use components, contact a Holland Sales Engineer today.
*A Special thanks to Sade Mokuolu @ WMFTG BioPure for her help in putting this blog together