1. USP Class VI Sealing Products: Seven Types

    USP Class VI sealing products encompass a broad spectrum of geometries, materials, and manufacturing approaches. From simple O-rings and gaskets to complex diaphragms, valve seats, and custom molded parts, these seals play a critical role in ensuring product safety, regulatory compliance, and reliable performance in high-purity environments. Engineers selecting these seals must carefully evaluate sterilization resistance, chemical compatibility, and extractables, all while aligning with industry-specific regulatory frameworks.

    ElastaPro makes USP Class VI silicone materials as solid silicone sheet and uncured silicone compound. For service, quality, value and speed, contact ElastaPro.

    Types of USP Class VI Sealing Products

    There are seven major types of USP Class VI sealing products.

    • O-rings
    • Gaskets
    • Diaphragms
    • Sealing Profiles and Extrusions
    • Sanitary Seals and Tri-Clamp Gaskets
    • Custom Molded Sheets
    • Valve Seats and Sealing Components

    The following sections describe them.

    1. O-Rings

    O-rings are the most common and versatile USP Class VI sealing products used in biomedical and pharmaceutical equipment.

    • Materials: USP Class VI–certified elastomers such as silicone, fluorosilicone, EPDM (ethylene propylene diene monomer), and FKM (fluoroelastomer). Silicone and EPDM are especially common due to their chemical resistance and cleanroom compatibility.

    • Applications: O-rings are used in syringe pumps, bioreactors, peristaltic pumps, chromatography systems, and aseptic connectors. Their circular geometry provides uniform compression and reliable sealing even under pressure cycling.

    • Key Benefits: Ease of installation, broad chemical compatibility, and resistance to sterilization methods such as autoclaving, gamma irradiation, and ethylene oxide (EtO) treatment.

    2. Gaskets

    Gaskets provide flat sealing between two rigid surfaces, typically flanges.

    • Materials: USP Class VI silicone sheets, PTFE (polytetrafluoroethylene) composites, and perfluoroelastomers (FFKM). PTFE-encapsulated silicone gaskets are often specified when chemical resistance and biocompatibility are both required.

    • Applications: Sterile process piping, pharmaceutical mixing tanks, bioprocessing skids, and clean-in-place (CIP) systems. In these environments, gaskets prevent contamination and maintain sterile boundaries.

    • Key Benefits: Large sealing surface, customizable geometry, and high resistance to process fluids ranging from solvents to biological media.

    3. Diaphragms

    Diaphragms are flexible membranes that separate two environments while allowing pressure or mechanical force to be transmitted.

    • Materials: USP Class VI–approved silicone, EPDM, or PTFE-lined elastomers. Some diaphragms are multilayer composites that combine flexibility with chemical inertness.

    • Applications: Diaphragm valves, pump heads, and pressure regulators in biopharmaceutical systems. They are especially critical in applications where sterility and purity must be maintained without direct fluid leakage.

    • Key Benefits: Smooth, crevice-free geometry that reduces bacterial entrapment; compatibility with sterilization; and long fatigue life under cyclic loading.

    4. Sealing Profiles and Extrusions

    Custom sealing profiles, sometimes referred to as extruded seals, are widely used in pharmaceutical isolators, medical enclosures, and sterile filling equipment.

    • Materials: USP Class VI silicone rubber is the dominant choice due to its flexibility, clarity (in translucent grades), and resistance to repeated sterilization. Thermoplastic elastomers (TPEs) are also used in some extrusion profiles.

    • Applications: Door seals in cleanrooms, chamber gaskets for lyophilizers, and perimeter seals for glove boxes. They maintain controlled atmospheres and prevent ingress of contaminants.

    • Key Benefits: Continuous lengths with minimal splicing, availability in bulb, U-channel, and custom geometries, and low compression set for long-term sealing.

    5. Sanitary Seals and Tri-Clamp Gaskets

    Sanitary seals are standardized USP Class VI sealing products used with hygienic fittings in biopharma and food processing.

    • Materials: USP Class VI silicone, EPDM, FKM, and PTFE. Some manufacturers also provide platinum-cured silicone versions, which reduce extractables compared to peroxide-cured variants.

    • Applications: Tri-clamp gaskets seal the joints in stainless-steel sanitary tubing systems. They are indispensable in dairy processing, vaccine production, and parenteral drug manufacturing.

    • Key Benefits: Easy assembly and disassembly for cleaning, compliance with both USP Class VI and FDA CFR 21, and surface finishes optimized for cleanability.

    6. Custom Molded Seals

    Not all sealing requirements can be met with standard geometries. Custom molded USP Class VI sealing products allow engineers to create shapes tailored to specific equipment.

    • Materials: USP Class VI elastomers including silicone, EPDM, and perfluoroelastomers. These can be compounded to balance mechanical properties with biocompatibility.

    • Applications: Seals for implantable devices, diagnostic cartridges, microfluidic platforms, and drug delivery systems. Custom seals often support innovations in life sciences where unique geometries are required.

    • Key Benefits: Optimized sealing performance, integration with device architecture, and scalability for high-volume production.

    7. Valve Seats and Sealing Components

    Beyond diaphragms, valve systems often require additional USP Class VI–compliant sealing parts such as valve seats, poppets, and bellows.

    • Materials: PTFE, perfluoroelastomers, or high-purity silicone. Material selection depends on chemical exposure and mechanical requirements.

    • Applications: Aseptic sampling valves, pinch valves, and dosing systems in sterile pharmaceutical manufacturing.

    • Key Benefits: High wear resistance, low extractables, and reliable sealing under dynamic movement and pressure cycling.

    Do you need USP Class VI silicones to fabricate products like these ? Contact ElastaPro.

  2. Healthcare Grade Solid Silicone Sheeting

    Does your stock room feel more like an emergency room these days? Everywhere you look, the materials you need seem to be in short supply.

    That’s why ElastaPro wants you to know we make healthcare-grade silicones that meet the following specifications.

    • USP Class VI
    • European Pharmacopeia
    • ISO 10993
    • FDA Title 21 CFR 177.2600.

    Here are the vital signs for our healthcare-grade elastomers.

    • Easily die-cut into gaskets for a superior sealing solution
    • Available in 30, 40, 50, 60, and 70 durometers (Shore A)
    • Thicknesses from .010″ to .500″ and Widths up to 60″
    • Acceptable for implant <29 days
    • No smell, no odor, no organic plasticizers
    • Phthalate and peroxide free
    • Safe for steam and gamma sterilization.

    Plus, we only use domestically produced silicone for our healthcare-grade materials.

    Would you like to learn more about what we can provide? Contact us.

  3. Buy Silicones from ElastaPro: Short Lead Times, Low MOQs & Flexibility

    Have you tried to buy silicones lately? These days it seems like everything is in short supply, including good news.

    Some of what you need to buy isn’t available, and what you can get takes too long to arrive or ties up too much cash because of high minimum order quantities (MOQs). Meanwhile, the requirements you’re expected to meet keep getting stricter.

    Fortunately, doing business with ElastaPro is about flexibility when you need to buy silicones. For stocked items, our lead times are typically as short as one to three days. For most made-to-order products, our lead times are two weeks. Plus, ElastaPro offers very low MOQs for all of our products.

    Whether you need solid silicone sheets, uncured silicone compounds, or specifications-grade silicones, you’ll get high-quality materials backed by exceptional service and superior technology. The materials you need are proudly Made in the USA, too.

    Buy Silicones from ElastaPro

    At a time when supply chains are constricted, many suppliers seem rigid. That’s not the case with ElastaPro. Find out how how our flexibility can help you. 

  4. Silicone Expo 2022: ElastaPro to Attend

    ElastaPro is pleased to announce that we will attend Silicone Expo, the world’s first free-to-attend commercial tradeshow and conference for the silicone industry.
    This in-person event is scheduled for June 21 to 23, 2022 at the TCF Center in Detroit, Michigan. As a member of the Silicone Expo Board of Advisors, I hope you can join us.

    Whether you’re a material supplier, a converter or fabricator, or a manufacturer that buys silicone products, you’ll gain access to:

    • 180+ exhibitors
    • two conference tracks
    • 65+ speakers
    • over 3500 buyers

    ElastaPro is thrilled to be a part of this event and can’t think of a better way to bring to bring together suppliers, specifiers, and fabricators for this all-encompassing event.
    From thermal management and light weighting to electrification and healthcare, silicones are part of today’s technologies and part of the solution to tomorrow’s challenges.

    See You at Silicone Expo?

    It would be great to see you in-person at the show. You can book a booth here.

  5. Silicone Supplies: Predicting What Tomorrow Will Be

    The car is packed. The trip to the beach is planned. The forecast was for clearing skies, but there’s rain on the windshield and gray skies up ahead. Why can’t they just predict the weather more accurately?

    Rainstorms and Supply Chains

    When ElastaPro first reported about silicone shortages in our March 2021 newsletter, we’d hoped that silicone rubber supply would stabilize during Q3 2021. As with so many forecasts, however, our prediction missed the mark – and the rain continues.

    By now, we’ve all heard reports about how major silicone suppliers have put customers on allocation or become super-selective about taking on new business. There’s news about rising prices and longer lead times, too.

    With the way things are looking, this “storm” will probably last until early 2022. So, what’s the latest version of the big picture, and what can we learn from the revised forecast?

    What’s Behind the Bad Weather?

    For starters, it’s important to understand that the current crisis is global in nature – and rather different than the supply shortage of 2018. Back then, the key factor was a shortage in Polydimethylsiloxane (PDMS) – the basic building block of silicone products. This was a result of some of these PDMS plants being taken offline due to maintenance or environmental concerns (primarily affecting the Chinese producers of PDMS). What’s changed in 2021 is less of an issue with PDMS and more in terms of people and ancillary products to convert the PDMS into elastomers and other key silicone products we all use. The Major Producers continue to struggle with catching up on their backlogs due to staffing, logistics, or shortages of ancillary and supporting products.

    Additionally, one of China’s largest basic suppliers of silicon metal and downstream silicone products is banned from selling into the U.S. and the EU. Even if you don’t buy directly from this company, you possibly use its intermediates in products that you purchase from other suppliers. Again, this is making things tough.

    Weathering the Storm with You

    ElastaPro continues to work aggressively to assure the continued supply of silicone elastomers and ancillary products to our customers. We’re also doing all we can to reduce the costs in our processes so that we can offset rapidly increasing prices for raw materials.

    Although we’ve had to increase our prices, the percentage of these increases has been well below what we are seeing in our raw materials. Moreover, we continue to maintain a two-week lead time on most made-to-order products. We’re also continuing to stock key silicone sheet materials for quick one-day turnarounds.

    Look to the Long-Term Forecast

    Our commitment to service goes well beyond wanting to provide you, our customer and partner, with the best quality and value in silicone sheeting and silicone compounds. We are also ensuring that we are doing all that we can to maintain a viable supply chain with quick turnaround times to provide the very best service to you.

    We’ll get through this together – and sooner than later, we hope. It might not seem like it now, but sometimes storm leave behind rainbows.

    Thank you for your continued support.

  6. Molded Silicone Sheets with Quick Deliveries

    ElastaPro is ready to supply you with solid silicone sheeting even if you need just a few yards of material. Our molded silicone sheets are made from high-quality ingredients and free from the curving that’s associated with roll stock. We offer quick turnarounds, too.

    Molded Silicone Sheets

    Check out these specs and let us know what you need:

    • Standard sheet size: 36″ x 36″
    • Durometer: 30 to 80 (Shore A)
    • Thickness: .250″ to 1″
    • Formulation: VMQ, PVMQ, or FVMQ
    • Specification Grades: FDA, UL, medical, electrically conductive
    • Commercial Grades: Available
    • Colors: Red, black, gray, or blue

    Made in USA Silicone Sheeting

    In these uncertain times, ElastaPro has the capabilities and flexibility to provide what you need when you need it. All of our silicone products are Made in the USA by a team that’s committed to bringing you the greatest value and finest customer experience.