Valves, Regulators, and Seals

High-performance polymers for demanding valve, regulator, and sealing applications

The polymers used for the sealing surfaces in valves and regulators must have low enough compressive modulus (stiffness) to conform to irregularities in mating metal surfaces while also being strong and stiff enough to maintain a seal. Additionally, plastic valve components must be able to operate in the presence of the process fluids without degrading from chemical attack and without contaminating the liquid or gas being processed. The plastics that are used for the friction and wear surfaces in valves must be carefully formulated to achieve the desired actuation torque. Finally, the specified plastic must have all of these properties throughout the operating temperature of the valve.

High-performance polymers for demanding valve, regulator, and sealing application. Learn more at Curbell Plastics.Curbell’s high-performance plastics are available in formulations that have the following characteristics that are beneficial for the sealing components in valves and regulators.

  • Moderate compressive stiffness for consistent sealing performance
  • Compatible with a wide variety of industrial chemicals
  • Purity – won’t contaminate process fluids
  • Capable of operating from cryogenic to elevated temperatures
  • Low friction to achieve the desired actuation torque without the use of external lubricants
  • Low wear on mating metal parts
  • Excellent creep and stress relaxation characteristics to ensure reliable sealing
  • Dimensional stability for tight tolerance sealing applications
  • Sound damping characteristics for reduced operating noise compared with all metal valve designs
  • Vacuum compatibility

Valve components that are often manufactured from high performance polymers:

  • Valve seats
  • Valve bodies
  • Seals
  • Pintle tips
  • Balls
  • Gaskets
  • Poppets
  • Bushings

Plastic Materials Typically used in Valves, Seals, and Regulators

Acetal (Delrin®) is an engineering plastic with low friction, good chemical resistance, and outstanding machining characteristics.

Plastic materials for high performance seals. Learn more at Curbell Plastics.Fluoropolymers (PTFE, PVDF, FEP, PFA, ETFE, ECTFE, and PCTFE)  are plastics with high operating temperatures, purity, and stain resistance.

PEEK is a high performance polymer that can be used at high and low temperatures. Excellent chemical resistance and stain resistance. Low leaching and low outgassing help to maintain the purity of process fluids. Friction and wear grades have outstanding wear performance.

Polypropylene is a low cost machinable plastic with excellent chemical resistance.

PVC is a chemically resistant plastic that is easy to assemble via solvent cements or thermoplastic welding.

PAI (Torlon®) is a strong and stiff high-performance polymer that can be used at elevated temperatures. Bearing grades have excellent friction and wear characteristics.

DuPont™ Vespel® Polyimide is a high performance polymer with excellent sealing characteristics. It can be used in extreme temperature environments. Friction and wear grades have low friction and outstanding wear properties.

Not sure which of these materials would be best for your application? View our Properties of Plastic Materials Typically used in Valves, Regulators, and Seals comparison table.

Need materials for valve, regulator, and sealing applications? Contact us today.

With access to the latest high-performance polymers – and the expertise to assist with material selection and troubleshooting – Curbell Plastics can help with all of your valve, regulator, and sealing application challenges.

We serve customers in all corners of the United States and Canada from locations nationwide. Nine of our locations and our corporate headquarters have ISO 9001 certification, and we maintain ITAR and EAR compliance company-wide.

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Frequently Asked Questions
Do you have plastics that can operate in the presence of aggressive chemicals?

Curbell supplies a number of plastic materials with broad chemical resistance including polyolefins (HDPE and PP), PEEK, PPS, and fluoropolymers (PTFE, PVDF, FEP, PFA, PCTFE, ETFE, and ECTFE). Detailed chemical resistance information can be found on our chemical resistance chart.

What plastics materials have low friction and long wear life so that they can freely slide against mating metal surfaces when a valve is actuated?

Friction and wear are complex properties. The best polymer formulation for a friction and wear application depends on a number of factors including load, velocity, and operating temperate range, as well as the type of metal and the roughness of the mating surfaces. Plastic materials perform well in a variety of friction and wear applications. Ask a Plastic Expert to help you identify candidate materials for your friction and wear application.

Which polymers can be used in elevated temperature environments?

There are a number of things to consider when selecting plastic materials for use in high temperature applications including the polymer’s mechanical properties, thermal expansion coefficient, thermal degradation behavior, and creep and stress relaxation characteristics. Curbell supplies a number of high temperature polymers including PEEK, PAI (Torlon®), and DuPont™ Vespel® Polyimide.

Which plastics will maintain purity and not contaminate process fluids?

Curbell Plastics supplies a number of high purity materials including PEEK, PVDF, FEP, PFA, ETFE, ECTFE, and PCTFE.

Which plastics will maintain tight seals over long periods of time?

The ability of a plastic material to maintain a seal will depend on a number of factors including its compressive modulus, its compatibility with the process fluids, and its stress relaxation characteristics within the required operating temperature range. Sealing performance will also depend on the roughness/smoothness of the surfaces of the plastic part and the metal counterface material. PEEK and DuPont™ Vespel® Polyimide have outstanding sealing characteristics.