November 16,2024
Roy

Lined ball valves feature a protective lining that offers superior corrosion resistance and can handle a wider range of temperatures, making them ideal for aggressive chemical applications. 

In contrast, unlined ball valves are typically made from metal and may require additional coatings for protection, leading to more frequent maintenance and a shorter lifespan in harsh environments. The choice between the two depends on the specific needs of the application.

Which valve is best suited for your application? Let’s find out!

What is a Lined Ball Valve?

A lined ball valve is a type of valve that features a ball with a hole through the middle, allowing fluid to pass through when aligned with the pipe. 

The interior surfaces of these valves are lined with materials like PTFE (Polytetrafluoroethylene) or Teflon, which provide excellent chemical resistance and durability.

Materials Used for Lining

  1. Polytetrafluoroethylene (PTFE): Known for its excellent chemical resistance and high-temperature tolerance, PTFE is ideal for handling strong acids and bases, with a temperature range of approximately -200°C to 180°C.
  1. PFA (Perfluoroalkoxy alkane): Similar to PTFE but with better mechanical properties, PFA is used for its high purity and resistance to a wide range of aggressive chemicals, making it suitable for industries like chemical processing and pharmaceuticals.
  1. FEP (Fluorinated Ethylene Propylene): Provides good chemical resistance and is used in applications requiring flexibility and transparency.
  1. PVDF (Polyvinylidene Fluoride): Known for its high mechanical strength and resistance to most chemicals and solvents.
  1. ETFE (Ethylene Tetrafluoroethylene): Known for its high mechanical strength and excellent weather resistance, ETFE is often used in architectural applications.
MaterialChemical ResistanceTemperature RangeMechanical StrengthElectrical InsulationPermeation Rate (g/m²/day)
PTFEExcellent-200°C to 260°CLowExcellent0.1 – 0.4
PFAExcellent-200°C to 260°CMediumExcellent.05 – 0.3
FEPExcellent-200°C to 205°CMediumExcellent0.1 – 0.25
PVDFGood-40°C to 150°CHighGood0.5 – 1.5
ETFEGood-200°C to 270°CHighExcellent0.2 – 0.6

Benefits of Using Lined Ball Valves

  1. Chemical Resistance: PTFE lined ball valves and Teflon lined ball valves offer excellent resistance to corrosive chemicals, ensuring long-term durability and reliability.
MaterialsResistant Chemicals
PTFE (Polytetrafluoroethylene)Acetic Acid (glacial)AcetoneHydrochloric AcidNitric AcidSulfuric AcidHydrogen PeroxideAmmonium Hydroxide
PFA (Perfluoroalkoxy)Acetic Acid (glacial)Hydrochloric AcidNitric AcidSulfuric AcidHydrogen Peroxide
FEP (Fluorinated Ethylene Propylene)Acetic Acid (glacial)Hydrochloric AcidNitric AcidSulfuric Acid
PVDF (Polyvinylidene Fluoride)Acetic Acid (up to 40%)Hydrochloric Acid (diluted)Nitric Acid (up to 20%)
ETFE (Ethylene Tetrafluoroethylene)Acetic Acid (up to 30%)Hydrochloric Acid (diluted)
  1. Chemical Compatibility: These lined valves are compatible with a wide range of chemicals, making them suitable for various industrial applications.
MaterialsCompatible Chemicals
PTFE (Polytetrafluoroethylene)AcetaldehydeAcetamideBenzeneChloroformCitric AcidDiethyl Ether
PFA (Perfluoroalkoxy)AcetaldehydeAcetamideBenzeneChloroformFormic Acid
FEP (Fluorinated Ethylene Propylene)AcetaldehydeBenzeneChloroform
PVDF (Polyvinylidene Fluoride)Ammonium HydroxideSodium Hydroxide (diluted)
ETFE (Ethylene Tetrafluoroethylene)Sodium Hydroxide (diluted)
  1. Reduced Maintenance: The lining materials, such as PTFE, minimize wear and tear, reducing the need for frequent maintenance and replacements.
  1. Improved Flow Characteristics: Inline ball valves and in line ball valves provide smooth and efficient flow control, reducing pressure drops and energy consumption.
  1. Leak Tightness: The precise construction of PTFE valves and PTFE ball valves ensures excellent sealing capabilities, preventing leaks and contamination.

What is an Unlined Ball Valve?

An unlined ball valve is a type of valve that does not have an internal lining to protect against corrosion or chemical attack. 

These valves are typically made from materials like stainless steel, brass, or PVC, and are used in applications where the fluid being handled is not corrosive or chemically aggressive.

Materials Used for Unlined Ball Valves

Unlined ball valves are typically made from materials that can withstand the specific conditions of the application without the need for additional lining. Here are some common materials used:

  1. Stainless Steel: Grades like 304 and 316 are popular due to their excellent corrosion resistance and durability. Stainless steel is often used in applications involving water, oil, and gas.
  1. Brass: Known for its good mechanical properties and corrosion resistance, brass is commonly used in residential and commercial plumbing.
  1. Carbon Steel: Grades such as WCB and LCB are used for their strength and cost-effectiveness, especially in non-corrosive environments.
  1. PVC (Polyvinyl Chloride): Lightweight and resistant to a wide range of chemicals, PVC is used in low-pressure applications.
  1. Bronze: Offers good corrosion resistance and is often used in marine environments.

Benefits and Limitations of Unlined Ball Valves

AspectBenefitsLimitations
Cost-EffectiveLess expensive than lined valves like PTFE lined ball valvesNot suitable for handling corrosive or aggressive chemicals
DurabilityMade from robust materials like stainless steel or brassMaterials can corrode over time in certain environments
Ease of OperationSimple to operate, providing quick and reliable shut-offNot recommended for throttling applications
Low MaintenanceRequires less maintenance compared to lined valvesHigher risk of leakage without additional sealing provided by a lining
VersatilitySuitable for a wide range of applications, including water, oil, and gasLacks the chemical resistance and durability of lined valves

Key Differences Between Lined and Unlined Ball Valves

AspectLined Ball ValvesUnlined Ball Valves
Corrosion and Chemical ResistanceExcellent resistance due to PTFE or Teflon lining, ideal for handling corrosive chemicalsLimited resistance, suitable for non-corrosive fluids like water, oil, and gas
Pressure and Temperature SuitabilitySuitable for a wide range of pressures and temperatures, typically up to 160°C (320°F) and 250 psiSuitable for moderate pressures and temperatures, depending on material (e.g., stainless steel up to 200°C (392°F) and 16 bar (232 psi)
Materials and ConstructionLined with materials like PTFE or PFA; body often made of stainless steel or ductile ironMade from materials like stainless steel, brass, or PVC
Industries UsedChemical, petrochemical, pharmaceutical, pulp and paper, semiconductor, miningResidential, commercial plumbing, oil and gas, general manufacturing
MaintenanceLower maintenance needs due to corrosion resistance; longer lifespan in harsh environmentsHigher maintenance needs; potential for corrosion and wear in certain environments
Cost-EffectivenessGenerally more expensive due to the lining materials and manufacturing processMore cost-effective for general-purpose applications

Conclusion

Choosing between lined and unlined ball valves depends on your specific application needs, especially regarding chemical resistance and cost. 

Lianke Valve offers high-quality fluorine lined ball valves that provide excellent durability and corrosion resistance, making them ideal for demanding industrial environments. 

Ready to enhance your system’s performance? Contact Lianke Valve today to find the perfect solution for your needs!

FAQs

  1. Can lined ball valves be used in high-temperature applications?

Answer: Yes, lined ball valves, especially those lined with materials like PFA, can handle higher temperatures compared to unlined ball valves. PFA-lined valves can typically withstand temperatures up to 260°C (500°F), making them suitable for high-temperature applications.

  1. What are the common industries that use unlined ball valves?

Answer: Unlined ball valves are commonly used in industries such as HVAC (Heating, Ventilation, and Air Conditioning), water treatment, and food and beverage processing. These industries often handle non-corrosive fluids, making unlined ball valves a cost-effective choice.

  1. How does the installation process differ between lined and unlined ball valves?

Answer: The installation process for both lined and unlined ball valves is generally similar, involving proper alignment and securing of the valve in the pipeline. However, extra care must be taken with lined ball valves to avoid damaging the lining during installation, which could compromise their chemical resistance.

Reference

Different Types of Fluorine Lined Valves and Their Applications

What Are PFA Lined Ball Valves?

The A to Z of Valve Materials

Chemical Resistance Guide of PTFE & Filled PTFE

Polytetrafluoroethylene (PTFE) and Teflon® Chemical Compatibility Chart

RECOMMENDED BLOG
December 20,2024
Roy
Top 10 Diaphragm Valve Manufacturers in 2024

Diaphragm valves are indispensable in industries requiring precise fluid control and contamination-free operations.  These valves excel in applications like water treatment, pharmaceuticals, and chemical processing, ensuring reliability and durability.  Selecting the right diaphragm valve supplier is essential to meet your specific system needs. Here’s a comprehensive guide to the Top 10 Diaphragm Valve Manufacturers in […]

Read More
December 20,2024
Roy
How Does a Diaphragm Control Valve Work?

Imagine a pharmaceutical plant mixing delicate ingredients or a water treatment system precisely regulating flow. In these scenarios, accuracy and contamination-free performance are crucial.  Enter the diaphragm control valve—a highly reliable valve designed to manage flow rates with precision while maintaining a clean, leak-free operation. Unlike other valves, diaphragm control valves use a flexible membrane […]

Read More
December 20,2024
Roy
When Should a Stop Valve Be Used?

Picture this: a pipe bursts in your home, and water gushes everywhere. What’s the first thing you need? A stop valve.  From homes to factories, stop valves provide the ability to shut off water, steam, or other liquids in emergencies or routine maintenance. But stop valves aren’t just for crisis control—they play a vital role […]

Read More
December 20,2024
Roy
What is the Difference Between Y and T Strainers?

Imagine a busy water treatment plant or oil refinery pipeline, handling massive liquid volumes every day. Even small debris—rust, dirt, or particles—can wreak havoc on pumps, valves, and equipment.  That’s where basket strainers come in, acting as silent protectors to catch impurities and keep systems running smoothly.  Two of the most reliable designs are the […]

Read More
FOR FURTHER INFORMATION
CONTACT US
Contact Lianke +