Vulcanised Seals 'O'-rings

Available Material Options for Vulcanised O-Rings

The performance of a vulcanised ring depends heavily on the material chosen for the cord. Each elastomer offers its own level of flexibility, temperature stability, and media resistance, making it important to match the ring to the working environment. We provide multiple elastomer options so industries can select the material that best matches their application needs.

1. Viton O-Rings (FKM) 75/90 Sh A

A Viton O-ring is chosen when an application demands strong resistance to heat, chemicals, and aggressive media. Its stability makes it a reliable option for harsh industrial environments.

Key properties:

• Handles temperatures from -20°C to +200°C
• Strong resistance to oils, fuels, solvents, and chemicals
• Low gas permeability for stable sealing
• Performs well in high-vacuum conditions
• Good compression set resistance for long service life

Best suited for:

• Chemical processing equipment
• Petrochemical systems
• High-temperature pipelines
• Oil and gas sealing points

These rings are widely used in systems where consistent performance and long-term reliability are essential.

2. Silicone O-Rings (VMQ) 70 sh A

A Silicone O-ring is used when an application requires clean, flexible, and temperature-stable sealing. Its purity and softness make it ideal for environments where hygiene and consistency matter.

Key properties:

• Works reliably from -40°C to +200°C
• Highly flexible, even at low temperatures
• Available in FDA and food-grade variants
• Odourless and chemically neutral
• Excellent aging and weather resistance

Best suited for:

• Food and beverage equipment
• Pharmaceutical and biotech systems
• Medical devices
• Water purification setups

These rings are preferred in applications that demand gentle sealing without compromising cleanliness or performance.

3. EPDM O-Rings 70 Sh A

An EPDM O-ring is selected for applications involving water, steam, or outdoor exposure. Its strong resistance to weathering makes it a dependable choice for long-term sealing.

Key properties:

• Temperature range: -20°C to +150°C
• Excellent resistance to water and steam
• Strong UV and ozone stability
• Not suitable for oils or fuel-based media
• Good overall durability in harsh outdoor conditions

Best suited for:

• Water treatment systems
• Steam lines and boilers
• HVAC equipment
• Outdoor sealing applications

These rings are often chosen for systems that are exposed to continuous moisture, heat, or other environmental conditions.

4. Nitrile O-Rings (NBR) 70/ 80 / 90 Sh A

A Nitrile O-ring is a practical and economical choice for systems that operate with petroleum-based oils. Its strong mechanical properties make it suitable for everyday industrial use.

Key properties:

• Temperature range: -30°C to +90°C
• Good resistance to petroleum oils and lubricants
• Strong mechanical strength and abrasion resistance
• Reliable performance in general hydraulic systems
• Cost-effective for large-volume applications

Best suited for:

• Hydraulic equipment
• Pneumatic tools
• Lubricated machinery
• General industrial sealing

These rings are commonly used in equipment that requires dependable sealing at a low cost.

5. HNBR 70/90 Sh A

A synthetic polymer that results from the hydrogenation of Nitrile rubber (NBR). This gives it superior mechanical characteristics, particularly high strength, greater thermal stability and helps reduce extrusion and wear. It can be used where temperatures are too high for standard Nitrile (NBR).

Key properties:

• Temperature range: -40°C to +165°C
• Excellent resistance to petroleum oils, chemical, ozone and abrasion
• Higher mechanical strength and flexibility
• Reliable performance in long term demanding application

Best suited for:

• Automotive
• Oil & Gas drilling
• Hydraulic systems
• General industrial sealing

We guide customers in selecting the right material by considering factors such as media compatibility, pressure levels, temperature range, and any applicable regulatory standards.

How Vulcanised O-Rings Are Manufactured

Vulcanised O-rings follow a precise manufacturing flow to ensure durability and accurate sealing. Each stage is handled carefully to maintain consistency and performance.

• Material Selection
  The right elastomer is chosen based on temperature, chemical, and pressure needs. Hardness between Shore A 50–90 is selected to match the required sealing performance.
• Precision Cord Cutting
  The cord length is calculated using:
  L = π × (D - d)
  This formula ensures the cord fits perfectly, with no gaps. Proper cutting prevents stress or stretching in the final O-ring.
• Joint Preparation
  The cord ends are 45° scarf cut, depending on the joint design. This helps create a smooth, strong bond area.
• Bonding
  A high-performance adhesive is applied to the prepared ends. It ensures proper alignment, so the O-ring maintains its original round shape.
• Vulcanising
  The joint is bonded under controlled heat and pressure. This forms a durable vulcanised connection that can handle demanding conditions.
• Curing
  The O-ring is cured to stabilise the material structure. This step ensures uniform mechanical properties and long-lasting sealing performance.
• Quality Inspection
  The final O-ring is checked for bond strength, dimensions, hardness, and surface finish. Every piece is inspected to ensure it meets quality standards.

The complete process ensures that the O-rings perform reliably in various applications. It also helps maintain consistent quality for every batch produced.

Joint Types We Offer

We offer multiple bonding styles based on the application and the required sealing performance. Each joint type delivers a different level of strength and suitability for industrial conditions.

• 1. Scarf Joint (Recommended)
  This joint uses an angled cut that increases the bonding surface. It ensures better grip and stability, making it ideal for dependable static sealing.
• 2. Butt Joint
  A straight cut bonds both ends directly. It is suitable for low-pressure static environments with minimal joint stress.
• 3. Overlap Joint
  One end overlaps the other before bonding. It is used only in special cases where the design requires this structure.
• 4. Moulded Joint (Premium Option)
  A fully moulded joint that offers the highest bond strength. It is preferred for critical or demanding applications that need maximum reliability.

With these joint types available, selecting the right option ensures better sealing performance and longer service life.

What Makes Vulcanised O-Rings Advantageous

Vulcanised O-rings are widely chosen because they offer design freedom that standard moulded rings cannot provide. They support industries that need custom sizes, quick supply, and dependable sealing in static operations.

• Manufactured in any diameter
  These rings can be produced in small, medium, or extremely large sizes. It helps meet special sealing dimensions without mould constraints.
• Quick turnaround times
  The vulcanising process is fast and controlled. This allows rapid supply for teams working with tight maintenance schedules.
• Cost-effective compared to moulded options
  No dedicated moulds are required for production. This lowers the overall cost for non-standard or low-volume requirements.
• Ideal for oversized equipment
  They perform well in large units such as tanks, manways, reactors, and industrial covers. The joint stays stable even at large circumferences.
• Multiple cross-section choices
  Different cord profiles can be selected based on the groove design. It helps achieve a better fit and improved sealing performance.
• Strong sealing for static environments
  They are designed to deliver consistent sealing in non-moving applications. The bonded joint is tested to ensure reliability.
• Resistant to chemicals and temperature variations
  Materials like Viton O-ring and Silicone O-ring provide strong resistance to heat, oils, and aggressive chemicals. This supports long-term service life in demanding conditions.
• Available in grades for regulated industries
  Special elastomer types meet FDA, pharmaceutical, and cleanroom requirements. These grades ensure safe use in sensitive environments.

These advantages make vulcanised O-rings a practical solution for industries needing customised sealing. Their adaptability helps maintain performance even in challenging operating conditions.

Constraints of Vulcanised O-Rings

While vulcanised O-rings offer many benefits, they also have certain limitations that users should consider. Understanding these drawbacks helps in choosing the right sealing option for each application.

• Not ideal for high dynamic motion:
  These rings are designed mainly for static use. Continuous movement can affect joint stability over time.
• Joint may be weaker than a moulded O-ring:
  The bonded section is the most sensitive point. It may not match the uniform strength of a fully moulded ring.
• Not suitable for high-pressure pulsating environments:
  Frequent pressure spikes can put stress on the joint. This reduces sealing efficiency and overall service life.
• Not recommended for rotary equipment:
  Rotational movement creates friction and heat. This can cause premature failure in vulcanised joints.

Knowing these limitations helps ensure the right O-ring type is selected for long-term reliability. Choosing the proper seal prevents downtime and improves equipment performance.

Where These O-Rings Perform Best

Large diameter O-rings produced through vulcanisation are widely used in static sealing applications where standard moulded rings are unavailable. Vulcanised O-rings are chosen for a wide range of static sealing tasks across industrial environments. Their ability to match large diameters and custom sizes makes them suitable for both standard and specialised equipment.

They are commonly used in areas such as:

1. Process & Storage Equipment

• Tank lids
• Manways
• Large industrial vessels
• Marine hatch covers

2. Fluid & Chemical Handling

• Filtration systems
• Chemical lines
• Solvent pipelines
• Water treatment units

3. Hygiene-Critical Industries

• Food and beverage machinery
• Pharmaceutical processing equipment

4. Technical & Mechanical Systems

• HVAC and refrigeration units
• Vacuum chambers
• Industrial mixers and reactors

From small enclosures to oversized assemblies, these applications highlight the adaptability of vulcanised O-rings. Their flexibility in diameter and material choice ensures consistent sealing performance across different industrial setups.

Cross-Section Sizes Offered (Cord Diameters)

Choosing the right cord diameter ensures that a vulcanised O-ring fits securely in its groove and delivers reliable sealing. To support different industrial setups, a wide range of standard sizes is available.

Standard cord diameters:

• 1.8 mm
• 2.0 mm
• 2.5 mm
• 3.0 mm
• 3.5 mm
• 4.0 mm
• 5.0 mm
• 6.0 mm
• 8.0 mm
• 10.0 mm
• 12.0 mm
• 13.0 mm
• 14.0 mm
• 15.0 mm
• 16.0 mm
• 18.0 mm
• 20.0 mm

If you need a specific or uncommon size, custom diameters are available on request. This ensures the O-ring matches your exact sealing profile without compromising performance.

Key Technical Parameters

Every vulcanised O-ring is manufactured to meet strict industrial standards, ensuring consistent performance across different sealing conditions. These specifications support reliability, accuracy, and long-term durability in static applications.

These are the core technical details we maintain:

• Hardness range: 70–90 Shore A
• Temperature resistance: varies by material type
• Dimensional tolerance: ISO tolerance standards
• Bond strength: verified using ASTM test methods
• Compression set: measured as per ASTM D395
• Material certification: available upon request

These controlled parameters help each ring deliver stable sealing, even under pressure changes, chemical media, or temperature fluctuations. Vulcanised large diameter O-rings offer a reliable, cost-effective sealing solution for industries requiring oversized, custom-built seals.

Comparison: Vulcanised O-Rings vs Moulded O-Rings

Choosing the right sealing option becomes easier when you understand how both solutions differ in performance and design. This comparison highlights the practical differences between vulcanised O-rings and moulded O-rings for everyday industrial use.

Recommended Installation Steps

Installing a vulcanised O-ring the right way helps the seal work efficiently and last longer. Even small mistakes during fitting can affect its performance. Follow the steps below to keep the installation simple and problem-free:

• 1. Clean the groove:
  Clear out dust, residue, or traces of old seal so the O-ring sits evenly without obstruction.
• 2. Avoid twisting the ring:
  Place it gently into the groove to keep its shape uniform and avoid uneven compression.
• 3. Do not stretch over sharp edges:
  Sharp corners can tear the material or weaken the joint during fitting.
• 4. Apply a suitable lubricant:
  A compatible grease reduces friction, allowing the ring to slide into place without stress.
• 5. Keep the joint in a static zone:
  Position the bonded section where there is minimal movement or pressure change.
• 6. Avoid the sealing path:
  Make sure the joint does not sit in the primary compression area to maintain consistent sealing.

These steps help extend the ring’s life and support long-term sealing accuracy. A careful installation always leads to a more stable and reliable seal.

Industries That Trust Our Solutions

Many industries rely on vulcanised O-rings for dependable sealing and long-term performance. Their durability and compatibility make them suitable for a wide range of applications. Here are the key sectors where they are commonly used:

• 1. Pharma
• 2. Food & Beverage
• 3. Chemical Processing
• 4. Water Treatment
• 5. Marine
• 6. Oil & Gas
• 7. Automotive
• 8. HVAC
• 9. Packaging
• 10. General Industrial Manufacturing

These industries demonstrate the versatility of vulcanised O-rings across diverse environments. Their consistent performance makes them a trusted choice for critical operations.

Your Order Input Checklist

Placing an order becomes much easier when all required details are shared from the beginning. It helps us accurately match your O-ring requirements and avoid back-and-forth. Use the checklist below to make sure your vulcanised O-rings are manufactured to the exact specification you need:

• Inside diameter (ID) or circumference
  This tells us the exact size the O-ring must fit into.
• Cord diameter (CS)
  The cord thickness helps determine how well the seal will perform.
• Material (Viton, Silicone, EPDM, NBR, etc.)
  The right material ensures the O-ring can handle your operating conditions.
• Shore hardness
  Hardness defines how firm or flexible the ring should be for your application.
• Quantity
  Help us plan production and deliver within your timeline.
• Application details (temperature, media, pressure)
  These conditions guide material choice and confirm performance suitability.
• Technical drawings
  Drawings remove any confusion and ensure complete dimensional accuracy.

Sharing clear details speeds up the process and ensures every O-ring is made exactly as required. It also helps deliver a product that performs well and remains reliable over the long term.

What Sets KAF Apart

Choosing the right supplier makes a major difference in O-ring performance and reliability. Our team ensures every order meets precise industrial standards and delivers long-term value. Here’s why many industries trust us:

• Official distributor of Vulcan Engineering (UK & USA)
  This gives you access to globally trusted vulcanised O-rings with certified quality.
• High-quality joint bonding
  Each joint is bonded with accuracy to ensure consistent sealing performance.
• Fast delivery and custom manufacturing
  We support urgent requirements with quick production and made-to-size options.
• FDA, food-grade, USP VI, EC1935/2004 options
  Materials are available for regulated industries that require strict compliance.
• Technical material selection support
  Our team helps you choose the right elastomer for temperature, media, and pressure needs.
• In-house sealing experts
  Specialists are available to guide design, troubleshooting, and application matching.
• Proven performance across 20+ industrial sectors
  Our vulcanised O-rings are widely used in demanding environments, delivering reliable results.

Working with us ensures you get accuracy, support, and a product that performs well in your application. Every O-ring is made with care so you can install it confidently and focus on your operations.