What is High Pressure VR Lip Seal: Key Features, Benefits & Applications

VR Lip Seal

In modern industrial systems, sealing plays a vital role in ensuring performance, safety, and efficiency. When pressure levels are high and space is limited, traditional radial shaft seals often fall short. That’s where high-pressure VR Lip Seals step in.

These springless seals offer a smarter, more efficient solution for critical environments — whether you're sealing hydraulic pumps, gearboxes, or medical devices. In this blog, we break down what VR Lip Seals are, how they work, and why they’re increasingly preferred in high-performance applications. Our partner company, VR Dichtungen, specializes in high-quality lip seals. We at CV Technik collaborate with VR Dichtungen to deliver reliable sealing solutions for your complex high-pressure applications.

What Is a VR Lip Seal?

A VR Lip Seal is a springless radial shaft seal engineered for high-pressure, high-speed, and low-friction applications. Instead of relying on a metal spring for compression, it uses a pre-tensioned elastomeric lip supported by a rigid ring (metal or plastic). This design allows it to maintain a secure seal with minimal friction and no shaft damage — even at pressures up to 150 bar.

This makes VR seals suitable for both rotating and static sealing applications, especially where conventional lip seals would fail due to wear or leakage.

Key Benefits of VR Lip Seals

1. Handles Extreme Pressure – Up to 150 Bar

High-pressure VR seals can operate at:

• 10 bar (standard)

• 15 bar (medium duty)

• Up to 150 bar (special versions like SOA)

This makes them ideal for hydraulic systems, compressors, gearboxes, and other applications where fluid retention under pressure is critical.

2. Compact Design for Tight Installations

The VR seal's minimalist design saves space, making it perfect for compact or integrated systems like electric motors, actuators, or medical pumps.

3. No Spring, No Shaft Damage

Unlike traditional seals, which may dig into the shaft and cause scoring, the VR seal uses controlled elastomer pressure. It gently contacts the shaft without causing wear — resulting in longer shaft and seal life.

4. Very Low Friction = Energy Savings

The frictional force of a VR seal is significantly lower than a spring-loaded seal:

• Only 1/3 to 1/4 of the radial load

• Less heat generation

• Less torque loss
  This is ideal for energy-efficient designs, such as EV drive systems or precision machinery.

5. Safe for Food, Beverage, and Medical Use

VR seals can be made with FDA-approved elastomers, and the springless design eliminates the risk of metal contamination. These seals can withstand:

• Steam sterilization

• CIP/SIP cleaning

• Exposure to aggressive media

Perfect for food processing, pharma production, and cleanroom devices.

6. Flexible, Self-Compensating Lip

The sealing lip adapts to vibrations, misalignments, and shaft runouts, maintaining a leak-free seal even in challenging mechanical conditions.

7. Supports Lubrication and Emergency Dry Run

VR seals promote capillary lubrication, helping them last longer. Special materials like PTFE-blended elastomers allow them to temporarily run dry, making them ideal for mission-critical applications.

8. Material & Design Customization

VR Lip Seals are available in various:

• Elastomers: NBR, FKM, HNBR, EPDM, Silicone, PTFE, etc.

• Support Rings: Stainless steel, aluminum, carbon steel, bronze, plastic

This flexibility ensures compatibility with chemicals, temperatures, pressures, and installation needs.

9. Cost-Effective for Low and High Volumes

Thanks to simple tooling, VR seals can be produced efficiently in both small batches (prototypes) and mass production (1 million+ pcs) — without large setup costs.

Where are VR Lip Seals Used?

Industries and applications benefiting from VR Lip Seals include:

• ✅ Automotive & EV systems

• ✅ Hydraulic and pneumatic actuators

• ✅ Gearboxes and mechanical drives

• ✅ Medical pumps and lab equipment

• ✅ Food-grade mixers and packaging systems

• ✅ General industrial sealing

Whether the goal is zero contamination, high-pressure sealing, or longer service life, VR Lip Seals deliver.

How to Install a VR Lip Seal

How to Install a VR Lip Seal? Learn the step-by-step assembly process for VR radial shaft seals by VR Dichtungen GmbH.

Proper installation is crucial to ensure the seal’s optimal functionality and long service life. Only experienced technicians should install VR Lip Seals to avoid damage and leaks. Here are important points to consider during installation:

Preparation Before Assembly

• Cleanliness: Ensure no dirt, metal shavings, molding sand, or contaminated grease/oil are present.

• Tools: Use smooth, non-sharp tools and cover any sharp edges or grooves to avoid damaging the seal.

• Seal and Shaft Prep:

  • Grease the sealing lip chamber to about 2/3 volume with compatible grease (avoid excess grease between membrane and metal ring).

  • Lightly oil the shaft with mineral oil and spray the outside of the seal with 70% isopropanol solution for easier fitting.

Mounting the Seal

• For shafts with grooves, use a mounting sleeve to prevent damage.

• Use a press-in mandrel and press the seal into the housing bore on the outer casing only—do not apply pressure to the sealing lip.

• Press in the seal straight and parallel to the shaft axis without tilting.

Fitting the Shaft Through the Seal

• Insert the shaft with a slight rotating movement.

• If the sealing lips fold or pinch, slightly pull the shaft back with a twist to reset the lips.

• Check that the shaft surface is undamaged by seal support bodies.

• If the shaft is already installed, carefully slide the seal over the shaft with rotation, avoiding pinching the lips.

Post-Installation Check

• Confirm that the seal sits flush and the shaft rotates smoothly in both directions.

• Misaligned or tilted seals will fail to seal properly.

VR Lip Seal Frequently Asked Questions FAQ

1. What factors must be considered when designing a shaft for a VR Lip seal to ensure a long service life?
To ensure a reliable function and long service life of a VR Lip seal, key shaft parameters must be precisely designed. This includes diameter tolerance (ISO h11), roundness tolerance (IT 8), and proper surface finish (Ra = 0.2–0.8 μm, Rz = 1–5 μm, Rmax ≤ 6.3 μm). The shaft hardness should be at least 40 HRC for normal applications and a minimum of 55 HRC if the seal is exposed to external dirt or contaminated media.

2. How does surface twist on the shaft affect the performance of a VR Lip seal?
The sealing effectiveness of a VR Lip seal can be significantly impacted by surface twist or orientation on the shaft. A twisted surface (like a micro-thread) can convey the medium along the shaft, leading to leakage if the twist exceeds the seal’s capability. In single-direction applications, controlled twist can even enhance the sealing effect.

3. What machining method is recommended for preparing the shaft surface for VR Lip seal applications?
Plunge grinding without axial feed is recommended to create a torsion-free surface for VR Lip seal compatibility. Important parameters include avoiding whole number speed ratios between the grinding wheel and workpiece, using multi-grain dressing tools with minimal axial feed, and ensuring long dressing times for burnout.

4. What housing bore specifications should be followed to properly install a VR Lip seal?
The housing bore must be precisely designed to support the static sealing function of the VR Lip seal. Recommended parameters include:

• t1 = B × 0.85 (minimum)

• t2 = B + 0.3 mm (minimum)

• r2 = 0.7 mm (maximum)
  Concentricity and coaxiality should comply with DIN 3760 standards to prevent leakage between the seal’s outer face and the housing.

5. Can standard stainless steel be used with VR Lip seals, and is surface hardening necessary?
Yes, in many applications involving VR Lip seals, standard stainless steel can be used without hardening. However, for improved wear resistance and longevity, the shaft should have adequate hardness—ranging from 25–30 HRC for simple applications to at least 55 HRC in harsh or dirty environments.

6. How should VR Lip seals be stored to maintain their sealing properties over time?
VR Lip seals must be stored according to DIN 7716 / ISO 2230 standards to retain their functionality. The storage environment should be cool (around 15 °C), dry (65% relative humidity), clean, and well-ventilated. Proper storage prevents premature aging, hardening, and weathering of the seal material.

7. Are there specific environmental conditions or equipment to avoid when storing VR Lip seals?
Yes. The storage room for VR Lip seals must be free from ozone-generating devices such as laser printers and electrical equipment. Additionally, avoid storing solvents or materials that emit gases, as these can degrade the seal material and shorten its service life.

8. What are the most important precautions when installing a VR Lip seal?
To ensure proper function and long life of a VR Lip seal, installation must be clean and precise. Avoid sharp edges, metal shavings, dirt, remnants of molding sand, and contaminated lubricants. Also ensure there are no uncovered grooves during assembly. Cleanliness and correct orientation are essential to prevent seal damage or failure.

9. How should the VR Lip seal be prepared before installation?
Before installation, the seal and the sealing point must be prepared. Make sure the sealing lip is oriented correctly toward the medium or space to be sealed. For double-lip seals, fill the grease chamber to 2/3 volume using chemically compatible grease. Also, lightly oil the shaft with mineral oil and spray the seal’s outer diameter with 70% isopropanol to aid smooth fitting.

10. What tools or accessories are needed to install a VR Lip seal correctly?
A mounting sleeve is recommended, especially for shafts with tongue and groove connections. Use a press-in mandrel with a press-in device to install the seal parallel to the axis. Pressure should be applied only on the outer casing—never on the sealing lip—to prevent deformation or damage.

11. How do you install a VR Lip seal when the shaft is already mounted?
When the shaft is already in place, gently slide the VR Lip seal over it using a slight rotating motion. Make sure the sealing lips do not fold or get pinched during the process. Once the seal reaches the housing bore, use a pressure ring to press the seal in, ensuring it enters straight and parallel to the shaft.

12. How do you verify if a VR Lip seal has been installed correctly?
After assembly, the shaft must rotate smoothly without resistance. A clean and properly seated sealing lip is critical—bent or pinched lips indicate incorrect installation. Always turn the shaft in both directions to confirm proper seating. Seals installed at an angle will not function correctly and can lead to leakage or premature wear.

13. What are the key storage conditions for VR lip seals to ensure optimal performance?

VR lip seals must be stored according to DIN 7716 standards to prevent premature ageing and damage. This includes keeping seals in their original packaging until installation, protecting them from dust, dirt, and sharp objects, and avoiding unsuitable storage containers that may cause contamination or deformation.

14. How can improper seal removal from packaging affect the seal’s performance?

Improper removal using sharp or unsuitable tools can damage the outer diameter or sealing lip of the VR lip seal, leading to immediate leakage or significantly reduced service life. It is crucial to use appropriate tools designed for safe removal.

15. What should I consider when greasing a VR lip seal before installation?

Use clean, uncontaminated oil or grease recommended by your customer advisor. Avoid using unsuitable lubricants or over-greasing, as excessive grease can leak and cause operational issues, while insufficient grease increases rubber abrasion and shortens service life.

16. Why is the cleanliness of the installation site critical for VR lip seal performance?

Contaminants such as metal shavings, dust, or cigarette ash can damage the seal during installation, causing immediate failures or shortening the seal’s service life. Keeping the assembly environment clean prevents seal damage and ensures proper function.

17. What are the risks of using a corroded shaft with VR lip seals?

Corroded shafts can damage or contaminate the sealing lip during installation, causing leaks or premature failure. Shafts must be inspected for corrosion before installation, and corroded shafts should be reworked or replaced.

18. How does excessive press-in force during mounting affect the VR lip seal?

Applying too much press-in force can bend or damage the seal’s support body, leading to immediate leakage. The use of lubricants and controlling press-in force to manufacturer recommendations can prevent damage.

19. What problems arise from incorrect seal design or dimensions?

An improperly designed or dimensioned seal can cause immediate leakage or damage during installation. Coordination with a customer advisor ensures the seal design matches the application requirements and installation conditions.

20. What is the impact of using unsuitable corrosion inhibitors with VR lip seals?

Unsuitable corrosion inhibitors may chemically react with the sealing material or the oil, causing premature failure. Always consult a customer advisor and test corrosion protection agents for compatibility before use.

21. Can using hammer assembly damage VR lip seals?

Yes, hammer assembly can cause seal damage and immediate leakage due to improper force application. It is strongly recommended to avoid hammer mounting and use proper mounting tools and procedures.

22. How can contamination of grease in pre-lubricated seals be prevented?

Always keep the packaging sealed and protect it from dust and dirt. Only open and use the required quantity at a time, and close containers immediately after use to prevent grease contamination and ensure optimal seal performance.

Conclusion:

A VR Lip seal is a critical component designed to prevent leakage of fluids or contaminants along rotating shafts in machines. It’s widely used in automotive, industrial, and mechanical applications where reliable sealing is essential to protect equipment and maintain performance.

To ensure a VR Lip seal performs effectively and lasts long, it’s important to follow precise shaft specifications, store seals properly according to DIN 7716, and install them carefully using the right tools and clean conditions. Avoiding damage during removal and installation, using compatible lubricants and corrosion inhibitors, and controlling press-in force all contribute to maximizing seal life.

By understanding what a VR Lip seal is and applying these best practices, you can avoid premature failures and keep your machinery running smoothly.

If your application demands high-pressure resistance, shaft protection, energy efficiency, and compliance with food or medical standards, the VR Lip Seal is your answer.

It’s not just an upgrade from traditional seals — it’s a modern sealing technology designed to perform where others fail.

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