What is the basic function of a shaft seal?
The primary function of a shaft seal is to prevent fluids and external contaminants from passing through rotating machine components such as shafts. This is crucial in many industries where machinery must operate reliably and safely under demanding conditions. Shaft seals ensure that process media—such as oils or chemicals—remain contained while preventing dirt, water, and dust from entering the system.
For example, in the energy sector, where metal hoses and expansion joints reduce thermal stress, shaft seals support these components by preventing leaks and minimizing wear. They also play a critical role in other industries, such as the oil and gas sector, where sealing performance is essential for safety.
How to choose the right shaft seal for your application?
Choosing the right shaft seal depends on several operating parameters, including:
- Process media (e.g., oils, chemicals, water)
- Operating temperature
- Shaft speed (circumferential speed)
- Pressure differential
- Environmental conditions
When selecting materials, it is essential to consider chemical resistance and the ability to maintain sealing properties under demanding conditions. The seal must withstand the required pressure and temperature ranges to ensure optimal machine performance without overloading or premature wear.
KLINGER Finland offers a wide range of standard-sized and standard-type shaft seals as well as sealing materials suitable for various operating conditions.
Commonly used materials:
- NBR (Nitrile rubber)
Excellent resistance to mineral and vegetable oils as well as wear and aging.
Operating temperature range: -20 to +120 °C - FPM / FKM (Fluoroelastomer, e.g., Viton®)
Withstands high temperatures and chemical exposure—such as oils, fuels, and solvents.
Operating temperature range: -18 to +220 °C
We also offer metal-reinforced seals for applications requiring higher shaft speeds and temperatures.
What are the most common types of shaft seals?
The most common types of shaft seals are radial shaft seals and mechanical seals. Radial shaft seals are simple, cost-effective, and easy to install. They are often used in low-pressure applications such as engines and small machinery, providing excellent protection against dust and moisture.
KLINGER Finland’s selection includes:
- Conventional shaft seals (FKM and NBR)
Ideal for general rotating equipment such as gearboxes and pumps. - V-rings (NBR and FPM)
Function as both primary and secondary seals, for example to block external contaminants. - Fabric-reinforced rubber seals (TGU/TGA)
Provide mechanical strength in harsh operating conditions. - Secondary seals for plain bearings
Designed to complement the primary sealing system. - L2M shaft seals and BBS (DF and MX) type oil seals
Tailored solutions for heavy-duty applications.
Mechanical shaft seals, on the other hand, are designed for process equipment where sealing rotating shafts requires specialized solutions. These seals are particularly suitable for demanding environments such as screw conveyors, mixers, dryers, extruders, and pulp applications. In addition, they comply with ATEX standards for use in explosive atmospheres.
What kind of maintenance do shaft seals require?
Shaft seals must be regularly inspected as part of machinery maintenance routines. Periodic inspection, cleaning, and replacement are essential to maintaining the seal’s performance and longevity. Regular maintenance also helps identify issues caused by wear or damage before they lead to more serious failures.
It is vital to check seals for signs of wear and replace them in a timely manner to avoid risks associated with leaks. A well-maintained shaft seal can significantly extend the lifespan of machinery and improve its efficiency.
KLINGER Finland – your expert partner in shaft seal solutions
At KLINGER Finland, we offer a comprehensive selection of high-quality shaft seals for various industrial applications. We help you choose the right sealing solution based on your specific operating conditions—whether it involves high temperatures, chemical exposure, or demanding speeds.
Explore our products and contact our experts for more information.
