Apache Stainless Blog

Stainless Finishes for Hygienic Vessels are measured by an RA (Roughness Average) meter.  Manufacturers of custom vessels for life science, health and pharmaceutical industries adhere to strict design parameters to maintain compliance in these industries. The RA is a standard for an average of peaks and valleys on the metal’s surface, measured in microinches.  Here is the evolution of stainless material coming to Apache with RA designations as it is transformed into custom sanitary design vessels:

RA > 100 Mill Finish  A Mill Finish has an unpolished, dull-gray, matte appearance. This material type is the basis for supply for all stainless-steel flat products as well as the basis for additional finishing operations.  It is hot or cold rolled with an RA (Roughness Average) of more than 100 microinches, depending on the gauge of the material. 

RA 15 – 40 2B Mill Finish  2B Mill finish is widely used in food, chemical and pharmaceutical equipment applications. It is corrosion resistant and has a typical RA range of 40 (7 gauge) to 15 (16 gauge) microinches.

RA 29 – 58 No. 3 and No. 4 Finish  Mechanical polishing achieves these finishes. The No. 3 Finish uses a 120-grit abrasive and has a semi-polished finish with an RA range of 36 – 58 microinches.  The No. 4 Finishes uses a 150-grit abrasive and has a polished, brushed surface.  The RA range is 29 – 40 microinches.

RA 18 – 31 No. 4A  Also identified as No. 4 Dairy Finish, this finishes is required to meet the basic FDA 3-A standards. It uses a 180 grit and has a RA range of 18 – 31 microinches.

< 32 RA Pickle Passivation   Pickle Passivation often follows other manufacturing processes including welding and grinding. Also called Pickling, it is the immersion of the metal in a pickling bath or coating the material with pick­ling solution, such as nitric-hydrofluoric acid. The process removes both metallic contamination and heat-treating scales. Pickle passivated stainless steel has a matte appearance. Apache’s tests have confirmed improvements up to 25% in RA read­ings on material that has been pickle passivated.

Lowest RA Electropolishing Electropolishing is an electro-chemical process that removes surface materi­al from stainless steel. The process includes an immersion of the stainless-steel component into a temperature-controlled bath of electrolyte that is charged with a DC power supply. Electrolytes used in electropolishing are concentrated sulfuric and phosphoric acid solutions. The finish has a mirror appearance. Apache’s before/after tests have shown improvements in RA smoothness up to 50%; results vary depending on stainless material.

In the highest level of sanitary design applications the vessel is pickled after manufacturing and polishing, then electropolished.

Here is our Guide to Stainless Material and Finishes for Sanitary Vessel applications.

Vacuum or Pressure closures for small/portable ASME vessels

Many processors come to Apache for a vessel solution in the incubation stage of their business.  In some cases, they are looking for help to choose the right kind of vessel that will suit their needs and fit their budget.  While Apache provides custom ASME vessels for a range of industries, we also offer a line of standard vessels that often solve what these manufacturers need for their process.

The use of the vessel will determine whether it is a pressurized solution, non—pressurized or vacuum vessel solution. 

Vessels that require a minimum of 50 PSI, utilize a pressure closure.  Numerous applications, including heating or cooling process, containment, and pressurized dispensing often utilize pressures at or above 50 psi. 

It is important to note the safety and ASME requirements for pressure vessels, an ASME UM-mark is required for:

• Vessels 5 cubic feet of volume or smaller with pressures not exceeding 250 psi.
• Vessel 3 cubic feet of volume or smaller with pressures not exceeding 350 psi.
• Vessels 1.5 cubic feet of volume or smaller with pressures not exceeding 600 psi.

For vacuum requirements or non-vacuum applications, such as a storage vessel or collecting vessel, a vacuum closure may suit the application.

In the video, Nick Buchda, Apache’s Small Vessel Representative, demonstrates vacuum and pressure closures on our standard line of vessels.

Apache has produced stainless vessels with ASME certification for over 45 years, with other accreditations for pharmaceutical, life science and health industries including ASME UM, ASME U, FDA, 3-A, CRN, PED and BPE. 

Whether the vessel needs fit a standard vessel, modifications to a standard vessel or a custom solution, Apache has the experience to fulfill a range of critical, sanitary-design vessel solutions.

ASME is a leading developer of codes and standards in the mechanical engineering community. These standards enhance public safety and health as well as promote innovation.

The ASME (American Society of Mechanical Engineers) mark is a single certification marketing to signify the international mark of safety and quality. Recognized worldwide, manufacturers that provide ASME have a rigorous quality program, and a third-party review to authorize the use of the mark.

The U mark certifies that the pressured tanks or vessel conforms to the latest edition of the ASME code and that the pressure vessel has been designed and manufactured in accordance with ASME.  All aspects are approved by a Third party ASME Authorized Inspector (AAI). U stamps require an ASME inspector to witness the ASME hydro test.

Companies with a U mark undergo a review with the National Board every three years.

The UM mark certified that the pressure vessel or tank conforms to the latest edition of the ASME code and that the pressure vessel has been designed and manufactured in accordance with ASME. The UM vessel’s designation is related to the size of the tank/vessel.

• Vessels 5 cubic feet of volume or smaller with pressures not exceeding 250 psi.
• Vessel 3 cubic feet of volume or smaller with pressures not exceeding 350 psi.
• Vessels 1.5 cubic feet of volume or smaller with pressures not exceeding 600 psi.

While the American Society of Mechanical Engineers writes the rules for the new construction of pressure vessels and tank, the National Board of Boiler and Pressure Vessel Inspectors write the inspection code for new and repaired vessels.

The National Board of Boiler and Pressure Vessel Inspectors require a Certificate of Authorization and R stamp for the repair or alteration of boilers, pressure vessels and other pressure retaining equipment.

Apache has been ASME certified for over 45 years. In addition to ASME, Apache is accredited in many other global standards. By setting parameters for quality and compliance, we offer greater value for our custom stainless ASME tanks and vessels.

Custom vessel manufacturing to industries requiring compliance is what we do. There is a process for customer service and engineering that is required to get the custom vessel you require for your application. There are numerous specifications that will be required based on your process or level of compliance. Apache will work with you to explain and provide options in your vessel project. This collaborative effort will have to control cost and expedite timing for your custom vessel. 

Here are our 12 Project Engineering Steps to Ensure Vessel Compliance:

1. Understand the intent of the vessel.  Apache has 45 years of experience manufacturing custom vessels.  We can lead important project planning discussion if we know the intent or type of process in which the vessel will be used.
2. Ensure and Verify Design Conditions.  At this step, our project engineers look at the design conditions, process, temperatures, ASME and other compliance requirement and perform initial calculations.
3. Determine Finish Requirements. Once design is verified and viable, the project is examined for mechanical and electropolishing requirements, as well as access needed for fixtures and how that has an impact on the fittings.
4. Final Calculations.  In this step, the engineer provides final calculations to address issues, verify material thickness and fit of fittings.
5. Completion of Compliant Design.  The ASME/PED/CRN compliant design is completed in 3D Solid Works.
6. Order long lead time components.  The long lead time components such as the mixer, body flanges, heads are ordered. The supply chain is monitored carefully for timing, and any changes are communicated that may affect delivery.
7. Component Manufacturer Collaboration.  Apache leverages long term relationships with component manufactures to customize specifications to meet the needs of the process.
8. Custom Approval.  The customer receives approval drawings with 2D, 3D models.  There is often a series of collaborative meetings to finalize the design and approval.
9. ASME (or other faction) Submission.  The final design is submitted for ASME or other compliance agency for approval.  Apache also leverages long-term relationships with regulatory agencies to help facilitate a smooth process.
10. Detailed Drawings.  The engineering team completes the detailed drawings for the manufacturing process and fabrication can begin.
11. Tests / Certifications.  ASME tests are scheduled and performed by our Quality Assurance team to comply with the certifications required for the vessel.
12. Turn-over Packet (TOP).  The documentation packet can be completed after the vessel is manufactured and the TOP is developed and uploaded to our customer portal.

Apache’s engineering team articulates technical discussions and is open with timelines, cost and compliance-related issues. Our competence for a pharmaceutical or life science industry vessel is strongly supported in providing all compliance related deliverables.

The particular RA (Roughness Average) value is a requirement for stainless vessel manufacturing for federal, state or local compliance agencies across many critical industries. It is a crucial standard in these industries to maintain a clean system. The instrument used in the measurement is called a profilometer, which provides an average in micro inches. The smaller the number, the smoother the stainless material. It is common for high compliance vessels to have single digit RA readings on product contact surfaces.

In the construction of pharmaceutical, life sciences, or medical-use vessels, meeting the RA requirement may include several steps, including material selection, grinding, polishing and chemical finishing. Manufacturing processes can affect the RA measurement on stainless material, including forming, stamping and welding. In the video, we walk out of the manufacturing plant with our quality controls manager to show measurements on material in vessels being manufactured in various stages of production. 

Pickle Passivation and Electropolishing chemical finishes have a high degree of improvement on RA smoothness compared to material before it is treated. Pickle passivation, also referred to as descaling, removes the scales and leaves a clean matte finish, free from contamination. Electropolishing is an electrochemical process that dissolves surface metal, removing all embedded contaminants and creates a smooth, mirror finish. 

ASTM International (American Standard for Testing and Materials) is one of several standards that Apache upholds. ASTM A967 is the standard specification for Chemical Passivation Treatment for Stainless Parts. ASTM B912 is the standard specification for electropolishing stainless steel alloys. The ASME-Bioprocessing Equipment (BPE) standard was created for the pharmaceutical and bioprocessing industry. The BPE surface finish standard classifies surface finishes and the acceptance criteria for compliance. 

In the business of compliance vessels, there are numerous standards that are required to deliver the necessary codes in any given project. Follow our videos, blogs and e-books developed specifically to help our processing customers understand the manufacturing and compliance process.

Processors serving food or hygienic industries have varying degrees of compliance requirements for custom vessels solutions.  The designation of "sanitary" has a wide range of definitions depending on the customer, the industry or the standard.  

Since Apache provides custom engineering and manufacturing, we reference these levels to guide conversations so the precise specifications for compliance and function are met. This video is a brief overview how Apache defines base, mid, and high level sanitary vessels.  

BASE LEVEL

Apache refers to a base level design as an entry-level, food grade, chemical and general use vessel. Base vessel sanitary construction is typically defined as continuous, crack and crevice-free welds. Fixtures are threaded, such as couplings and dip tubes, an may include ANSI flanges and Thermowells probes.  Base level tanks and vessels are pickle passivated and are manually cleaned after use. 

MID-LEVEL

In custom sanitary vessel discussions, Apache defines mid-level vessels as COP (clean-out-of-place) capable.  There is a higher level of finishing on the inside dimension for mid-level criteria, and the construction fixtures are all sanitary specified, like tri-clamp ferrules, tube connection, NA connects, and sight glasses for example. Processes and applications for mid-level sanitary tanks include columns, solvent tanks, collection, extraction, mixing and dispensing. 

HIGH LEVEL

The highest level of sanitary design vessels are designed with CIP (clean-in-place) processes.  The finishing on high-level vessels are smoothly polished to less than 32RA (roughness average) on the inside of the vessel.  The chemical finish is both nitric passivated and electropolished on high-level vessel designs.  Customized high-level sanitary tanks have electropolished sanitary fittings from tri-clamp ferrules, tube connects, to orbitally welded j-tubes, and polished internal coils.  Highly compliant and sanitary vessels are used for processing, WFI, R&D lab equipment, heat and cooling, and nutsche filtering. 

For more information into the criteria of sanitary vessels, please read "Guide to Sanitary Design for Custom Vessels", a quick-read guide to sanitary standards, construction and the effects on delivery and cost. 

Apache Stainless Equipment Corporation is a manufacturer of stainless equipment for a range of hygienic industries, including, food, beverage, biotechnology, pharmaceutical, cannabinoid, and life sciences.

A dedicated quality control and compliance team directs all tests, certificates and documents for all sanitary, ASME, and global standards.

ASME (American Society of Mechanical Engineers) is a leading developer of codes and standards in the mechanical engineering community. ASME code section VIII details mandatory rules regarding vessel design, including engineering, manufacturing, and testing of pressure vessels.   These standards enhance public safety and health as well as promote quality and innovation.  Here are the main parameters outlining ASME construction of pressure vessels with supporting ASME testing requirements.

Construction
Parameters such as wall thickness, material, and flange rating are determined by the application, including pressure, temperature, corrosion allowance, and fluid flow.  These conditions are calculated and reviewed/approved by the ASME inspector when required per code. Stainless, Hastelloy, AL6XN, duplex, and Inconel materials are ASME-approved materials for pressure vessel construction in the pharmaceutical, life sciences, and health-related industries, of which Apache is qualified to fabricate.

Welding
ASME standards also define the quality, type, and finishing of the welds. Head styles (ASME F&D, 80:10, 2:1 Elliptical), seams, nozzles, manways, and other components are designed per ASME Code. Applicable ASME Code welding procedures must be followed using certified ASME welders to maintain the structural integrity of an ASME pressure vessel. Welders must be certified to a qualified weld specification qualified per ASME code guidelines.

Safety Components
Gauges, valves, pressure outlets, and drainage are required safety components in ASME design pressure vessels. The proper selection of components and design is critically important to the safety and performance of the ASME vessel. The selection of safety components needs to be evaluated closely to define the required scope of supply.

Finishing
There is another ASME specification to ensure the quality and safety of parts used in pharmaceutical, bio-processing, and other industries requiring a hygienic vessel, called ASMP-BPE. BPE (Bio Processing Equipment Standard) specifies the surface finishes RA (roughness average) requirements and pickle passivation and electropolishing requirements.

Tests & Certification
There are significant testing, certifications, and documentation requirements for ASME compliance and satisfying the numerous customer requirements. Many require ASME inspection as well as a TOP (turnover packet).  Some ASME testing and certification requirements include pneumatic, hydrostatic, liquid penetrant, saline, riboflavin, CIP coverage, material, base metal thickness, material trace, welder trace, Ferroxyl, PMI (Positive Material Identification) radiography, and UT.

Apache has been ASME certified for over 40 years. In addition to ASME, Apache is accredited in many other global standards. By setting parameters for quality and compliance, we offer greater value for our custom stainless ASME tanks and vessels.

As the Cannabis Processing industry continues to evolve, increasing regulations are following. With continuous new products and additive combinations entering the market, the sale and distribution of the products will have more regulations. The processing and production of CBD and cannabidiol components are already seeing increasing standards. 

When searching for a new Cannabis Processing or Extraction vessel equipment supplier, ask these five questions: 

1. Does the vessel supplier have experience with the types of processing equipment you require to produce your product? The vessel manufacturer should have experience with CBD and Cannabis processing vessels, extraction tanks, mixing tanks and separating vessels. For complex applications or scale solutions, you may need to consult a process engineering firm to solve your CBD process challenges.
2. If you aren’t sure about the type of equipment you need, do you have access to collaborate with the vessel manufacturer’s application and engineering team to discuss your challenges? There continues to be numerous start-ups for new types of CBD products, and that equipment can come at a high cost. There may be value in a collaborative meeting with application specialists to vet your project and costs and learn more about equipment offerings. 
3. What types of processes and components does the vessel manufacturer offer for the hygienic design? The FDA and other regulatory agencies will set the standard for sanitation and hygienic design in the CBD / Cannabis processing industry. Your vessel manufacturer must have offerings and experience with COP (clean out-of-place) sanitation and CIP (clean-in-place) sanitation components. They must also meet RA (roughness average) requirements and offer mechanical and chemical finishing services to meet the hygienic requirements set by regulatory agencies. 
4. Does the vessel manufacture hold ASME certification? Most local and state laws require vessels designed at 15 PSI and higher to be ASME certified. Moreover, ASME requirements are also in material specifications, construction, and welding qualifications. Determine all industry compliance accreditations, including FDA, 3-A, CRN, PED and BPE. 
5. Does the vessel manufacturer provide the testing and documentation services you need for your Cannabis or CBD processing vessel? There are significant testing, certifications, and documents requirements for all US and global accreditation programs. An experienced quality assurance department will provide trained and certified personnel; and assure the proper procedures and documentation to support your vessel. 

Apache Stainless is a manufacturer of sanitary, highly engineered, ASME pressure vessels for a multitude of industries, including cannabis processing, pharmaceutical, health and biopharma. We have served the Cannabis and CBD processing industry several years with processing tanks, hydrocarbon extraction tanks, mixing tanks and separating vessels. We also design and manufacture vessels with Canadian Registration Numbers (CRN) for all Canadian provinces. We have all Stainless ASME certified manufacturing facility with custom capabilities including heat exchange surfaces, agitation, CIP (clean-in-place) componentry and controls. Apache has an in-house quality and compliance team to provide all testing and documentation requirements.

Visit Small Vessels for more information.

Accreditations 

Custom and pressure vessel manufacturers must have accreditation for ASME certification. Compliance with the National Board of Boiler and Pressure Vessel code is required. Pressure vessel manufacturers must also manufacture to ASME material specifications, certificates, and welding qualifications.

Other accreditations are also crucial in the pharmaceutical, life science, and health industries. Confirm all industry compliance standards, including:
•    ASME UM
•    ASME U
•    FDA
•    3-A
•    CRN
•    PED
•    BPE

Quality Assurance & Compliance

Verify that the manufacturer has a dedicated quality assurance team.  There are significant testing, certifications, and documentation requirements for all global accreditation programs. In-house inspection services are a benefit to ASME projects. Review services that should include:
•    Pneumatic testing
•    Hydrostatic testing
•    Liquid Penetrant (Dye Penetrant) testing
•    Saline testing and certificate
•    Riboflavin/CIP (clean-in-place) coverage test
•    Material Test Reports
•    Base metal thickness certificate
•    Material trace
•    Welder trace
•    Ferroxyl test and certificate
•    Positive material identification (PMI) and certificate
•    Ferrite levels and certificate
•    Radiography and analysis
•    UT weld testing and certificate
•    Turn Over Packet (TOP) as required

Experience

The pressure vessel manufacturer must have expertise in the type of vessel and industry experience for the use of the vessel. Critical staff, fabricators, and welders must be ASME certified. All welders must be approved for the weld procedures required to make custom pressure vessels.

Experience and reputation are also significant when developing relationships with inspectors, agencies, and governing officials to keep the compliance process moving forward smoothly.  

Service & Support

Above all, assess the service and support provided by the manufacturer. The vessel manufacturer should be able to articulate technical discussions and be open and honest with timelines, cost, and compliance-related issues. Consider other research and questions, such as:

•    Is the proposal easy to understand and compare solutions?
•    Do you have direct access to the engineer for questions?
•    Does the company provide timely and accurate documentation?
•    Does the company offer after-market parts and field service?

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There are several reasons why a vessel may need service, however, two main causes why a vessel may need service are either accident or performance related.

In the case of an accident, such as a tool falling into the tank and causing damage; surface scratches and dents can typically be repaired on-site, provided they do not go beyond minimum requirements, with mechanical polishing or hand/wand electropolishing. 

Reduced agitator performance or failure is often due to worn parts, improper assembly or a bent or broken shaft.  Agitator repairs may be addressed with the agitator manufacturer or the vessel manufacturer, depending on the situation, down-time, and severity of the failure.

When troubleshooting a drop in pressure in a tank or vessel, a typical cause is often related to seals. One sign of seal failure is product coming out of the seal.  To help reduce the frequency of an unexpected seal leak occurring, it is recommended to use a good seal maintenance program to solve a lot of pressure / performance issues, such as:
•    Seal replacement has been neglected
•    Flat spots on seals are a sign for replacement
•    Improper or incorrect seals for the outlet
•    Nicks, scratches or mishandling of seals

A best practice is to avoid product waste and critical down-time is to inventory seals for all outlets and manage seals in a preventative maintenance program.

It is important to note that any weld repairs to the ASME pressures zones on tanks, require an R-Stamp.  The R-Stamp is a certification required by the National Board of Boiler and Pressure Vessels for repair of an ASME tank or vessel.

Depending on the size of the vessel and type of repair, Apache’s service techs may be able to make repairs on site or in some cases, tanks are shipped back to the factory. Apache can provide services including:
•    Field service and troubleshooting to all types of stainless and high alloy tanks
•    ASME / National Board R-Stamp repair and modifications
•    Surface finish repairs
•    Non-code repairs and modifications including piping and heat transfer jackets
•    Seal and agitation repairs and modifications
•    Accessory repairs
•    Head and tank shell repairs
•    Leak detection
•    Audit and service contract available

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