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Butterfly Valve Seats

At CEMATIC, we offer replacement seats for butterfly valves in the most commonly used elastomeric materials in the industry. We also have seats in EPDM, NBR, Viton, and PTFE to adapt to any fluid and process condition. All are compatible with Series 1 wafer butterfly valves, ANSI 150 standard, in sizes from 2" to 12". Therefore, they are the correct replacement when the original seat wears out and the valve loses its seal. Thanks to their timely replacement, you extend the lifespan of the entire valve without needing to purchase a new assembly. Furthermore, having replacement seats in inventory reduces plant downtime in the event of an unexpected failure. We also offer free technical advice to identify the correct seat material according to your fluid, temperature, and process. With immediate delivery throughout the Mexican Republic. Quote with us today!
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Butterfly Valve Replacement Seats - Viton and PTFE

We offer replacement seats for butterfly valves in the most commonly used elastomeric materials in the industry. Additionally, all are compatible with ANSI 150 Series 1 wafer valves in sizes from 2" to 12". Therefore, they are the correct solution when the original seat wears out and the valve loses tightness. Likewise, replacing only the seat extends the lifespan of the entire valve without needing to purchase a new assembly.

Why is it important to replace the seat on time?

The seat is the component that ensures the hermetic seal of the butterfly valve when closed. Thanks to it, fluid leaks into the system or to the outside are prevented. Therefore, when the seat wears out, the valve loses its closing capacity and can lead to product loss, cross-contamination, or unscheduled shutdowns. For this reason, identifying and replacing the seat on time is a fundamental preventive maintenance practice in any industrial plant. Furthermore, a seat in good condition ensures the correct operation of the actuator and reduces the operating torque required to maneuver the valve.

When should the seat be replaced?

There are clear signs that indicate the seat needs replacement. For example, if you observe any of the following conditions, it's time to act before the problem affects production. Below, we explain the most common ones:

  • Visible leaks when the valve is closed: This is the most evident sign of seat wear. Additionally, a small leak can rapidly increase if not addressed. Therefore, any leak in the closed position should prompt immediate seat inspection.
  • Increased operating torque to open or close: This indicates that the seat is deformed or damaged and creates greater friction on the disc. Therefore, if the operator needs more force to maneuver the valve, the seat likely needs replacement. Likewise, in automated valves, this can lead to actuator failures.
  • Visible deformation or hardening of the elastomer: Heat, chemicals, and operating cycles degrade the seat material over time. Thanks to a visual inspection during preventive maintenance, it's possible to detect cracks, hardening, or deformation before a leak occurs. Therefore, it is recommended to inspect the seat during each scheduled maintenance.
  • Change of fluid or process conditions: If the process fluid changes or operating temperatures increase, the current seat may not be compatible with the new conditions. Therefore, it is necessary to evaluate whether the installed seat material is still correct. Likewise, a seat incompatible with the fluid can degrade rapidly and cause leaks or contamination.

Available Materials: EPDM and NBR

Below, we present the seats available in standard materials. Additionally, each material has specific properties that make it ideal for certain fluids and operating conditions. Therefore, it is important to choose the correct one according to your process:

  • EPDM Seat (Ethylene Propylene Diene Monomer): This is the most common seat for potable water, hot water, low-pressure steam, and neutral fluids. Additionally, it resists working temperatures from -20°C to 150°C. Therefore, it is the standard seat in water systems, effluent treatment, HVAC, and irrigation. However, it is not compatible with mineral oils, hydrocarbons, or organic solvents.
  • NBR Seat (Nitrile Rubber): This is ideal for mineral oils, fuels, hydrocarbons, and petroleum-based fluids. Additionally, its working temperature ranges from -20°C to 90°C. Therefore, it is the recommended option in the automotive, petrochemical industries, and fuel systems. However, it is not suitable for hot water, steam, or acids. Likewise, it should not be used in contact with aromatic fluids or ketones.

Available Materials: Viton and PTFE

In addition to standard materials, we have seats in Viton and PTFE for applications with higher chemical or temperature demands. Therefore, if your process handles aggressive fluids or operates at elevated temperatures, you will find the appropriate option below:

  • Viton Seat (FKM — Fluoroelastomer): Offers the highest chemical resistance among the available elastomers. Therefore, it is the preferred seat for concentrated acids, aromatic solvents, hydrocarbons, and aggressive fluids at high temperatures. Additionally, it resists working temperatures from -20°C to 200°C. Likewise, it maintains its sealing properties under continuous use conditions without permanent deformation. Therefore, although its cost is higher, it represents the most durable option in demanding chemical applications.
  • PTFE Seat (Polytetrafluoroethylene — Teflon): It is chemically inert to almost all known fluids, including concentrated acids, strong alkalis, and aggressive solvents. Thanks to this, it is the only viable option when no elastomer is compatible with the fluid. Therefore, it is the most versatile seat from a chemical standpoint. Additionally, it complies with FDA food contact regulations, making it suitable for processes in the food and pharmaceutical industries. However, unlike elastomers, PTFE is more rigid, so it may require higher operating torque in the valve.

Quick Fluid Selection Guide

To facilitate the selection of the correct seat, below is a quick guide based on the most common fluids. Additionally, if your fluid does not appear on this list, our technical team can guide you at no cost. Therefore, do not hesitate to contact us before placing your order:

  • Potable water and process water: We recommend the EPDM seat. Additionally, it is the approved material for contact with potable water and resists chlorine and treatment products without degradation.
  • Hot water and low-pressure steam: We recommend the EPDM seat for temperatures up to 150°C. Therefore, it is the most economical and reliable option in HVAC and industrial heating systems.
  • Mineral oils and fuels: We recommend the NBR seat. Likewise, it is the standard option in refineries, automotive workshops, and fuel distribution systems.
  • Aggressive acids, solvents, and hydrocarbons: We recommend the Viton seat. Therefore, it is the preferred option in the chemical, petrochemical, and pharmaceutical industries when the fluid is aggressive and the temperature can be high.
  • Highly corrosive fluids or with FDA requirements: We recommend the PTFE seat. Additionally, it is the only option when no elastomer is compatible with the fluid, or when the process must comply with food or pharmaceutical contact regulations.

Compatibility and Available Sizes

All seats in this collection are compatible with ANSI 150 Series 1 wafer butterfly valves. Therefore, before placing your order, verify that your valve corresponds to this series. Likewise, they are available in the following sizes to cover most industrial installations:

  • Available sizes: 2", 3", 4", 5", 6", 8", 10", and 12". Therefore, they cover everything from medium installations to large diameter pipes in industrial plants. Additionally, if you require a size outside this range, contact us to check availability.
  • Compatibility: These are original spare parts compatible with ANSI 150 Series 1 wafer valves with cast iron and carbon steel bodies. Likewise, they are interchangeable between brands that follow the same dimensional standard. Therefore, verifying your valve's series before ordering ensures a correct fit.
  • Inventory recommendation: To reduce downtime, we recommend keeping at least one spare seat for each critical valve in your process. Thanks to this, any leak can be addressed immediately without waiting for delivery times. Finally, CEMATIC has stock available for same-day delivery in Mexico City.

Why choose CEMATIC?

  • Stock available in EPDM, NBR, Viton, and PTFE with immediate delivery throughout the Mexican Republic.
  • Additionally, we offer free technical advice to identify the correct seat material according to your fluid and process conditions.
  • We also have sizes from 2" to 12" in all available materials to cover most industrial installations.
  • Likewise, we are suppliers of complete butterfly valves, so we have thorough knowledge of the compatibility and correct fit of each seat.
  • Finally, we respond by phone, WhatsApp, and email on the same day.