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Soft PVC Sealing Washer 125M3 to M20 -
Soft PVC Sealing Washer 9021M4 to M20
Sealing Washers, Flat Gaskets and Rubber O-Rings
Rubber sealing washers, flat gaskets and O-rings provide reliable sealing in a wide range of industrial applications. They help prevent the leakage of liquids and gases while protecting pipe systems and fastening assemblies against moisture, dust and dirt. Flat gaskets are used wherever two flat surfaces need to be sealed. Their elastic materials conform to surface irregularities, ensuring a dependable and long-lasting seal.
O-rings made from NBR, EPDM, silicone or FKM are among the most widely used sealing elements in engineering and industry. Typically installed in a groove, they provide an effective seal with a simple design. Combined with a wide choice of materials, O-rings offer a cost-effective and versatile sealing solution for countless applications.
Sealing Materials: Synthetic Rubber as an Alternative to Natural Rubber
Different elastomers are used depending on the application and the required resistance to temperature, weathering, chemicals or mechanical stress. Today, most sealing washers, flat gaskets and O-rings are manufactured from synthetic rubber such as silicone, neoprene, NBR, EPDM or FKM, although natural rubber is still used for certain applications. For an overview of the chemical resistance of elastomers, see this comparison table. Depending on the material selected, rubber seals are suitable for a wide range of industrial applications, including:
- Machinery and plant engineering: Sealing housings, flanges, pumps, valves and pipe connections
- Automotive industry: Sealing engines, transmissions, cooling systems, fuel systems and hydraulic systems
- Plumbing and HVAC: Sealing threaded pipe connections, fittings and heating systems
- Electrical and electronics industry: Protecting enclosures against moisture, dust and dirt
- Food processing and medical technology: Hygienic sealing of equipment and machinery using suitable materials such as silicone or PTFE
- Chemical industry: Sealing tanks, vessels and pipeline systems
Red Vulcanised Fibre Sealing Washers from M2.5 to M20
Vulcanised fibre washers have been a proven solution for reliably sealing threaded connections in plumbing, heating and industrial applications for decades. Vulcanised fibre is a sustainable fibre material made from highly compressed cellulose fibres, offering excellent mechanical strength, good compressibility, dimensional stability and temperature resistance up to approximately +120°C. Thanks to their good resistance to many oils and greases, as well as their excellent electrical insulating properties, these sealing washers are ideal for a wide range of static applications.
Bülte offers a comprehensive range of vulcanised fibre washers in metric sizes from M2.5 to M20. They are suitable for professional applications in plumbing, heating and installation engineering, as well as many industrial sectors. Certificates confirming their suitability for drinking water installations are available on request.
Transparent Silicone Washers M4–M12 and Gaskets
Silicone is a high-performance elastomer offering outstanding resistance to extreme temperatures, UV radiation, ozone and weathering. Thanks to its excellent physiological properties, silicone washers, o-rings and gaskets are widely used in applications with stringent hygiene, cleanliness and material performance requirements, including the food processing industry, medical technology and laboratory equipment. Key properties and benefits of silicone gaskets, o-rings and sealing washers include:
- Excellent temperature resistance from approximately -60°C to +230°C
- Outstanding resistance to UV radiation, ozone and weathering
- Water-repellent and moisture-resistant
- Good resistance to many acids and alkalis
- Good electrical insulating properties
- Odourless and tasteless material
- Physiologically inert and suitable for a wide range of hygiene-critical applications
These properties make silicone gaskets and sealing washers the ideal choice for indoor and outdoor applications, as well as for environments exposed to high or widely fluctuating temperatures. The transparent silicone washers in the Bülte standard range are based on DIN 125 and are available in metric sizes from M4 to M12 for a wide variety of industrial applications.
NBR O-Rings – Diameters from 10 to 60 mm
NBR (Nitrile Butadiene Rubber) is one of the most widely used elastomers in sealing technology. It offers excellent resistance to mineral oils, lubricating oils, greases and many fuels, including diesel and heating oil. Thanks to its well-balanced mechanical properties, NBR is an ideal material for manufacturing NBR O-rings and gaskets used in machinery, automotive engineering, hydraulic and pneumatic systems. The key advantages of NBR seals include:
- Excellent resistance to oils, lubricants, greases and fuels
- Good abrasion and wear resistance
- High tensile strength and elasticity
- Excellent resistance to mechanical stress
- Temperature resistance from approximately -20 °C to +100 °C, depending on the grade
- Cost-effective sealing solution for a wide range of industrial applications
- Reliable sealing performance in both static and dynamic applications
NBR O-rings provide a cost-effective and high-performance solution for a wide range of sealing applications. They are easy to install and ensure reliable sealing against the leakage of liquids and gases. Bülte's standard range includes black NBR O-rings with diameters from 10 to 60 mm, offering proven quality and dependable performance for industrial applications.
Neoprene Washers and Gaskets
Neoprene washers (chloroprene rubber, CR) are widely used wherever threaded fasteners require a reliable seal, surface irregularities need to be compensated, vibrations reduced or electrical insulation provided. In many sealing washers, the neoprene element is bonded to a metal washer to combine effective sealing with high mechanical strength. This flexible elastomer offers excellent resistance to weathering, water, ozone and many hydrocarbons, making neoprene washers and gaskets suitable for a wide range of indoor and outdoor industrial applications. Their key advantages include:
- Excellent resistance to water and moisture
- Good resistance to weathering, ozone and ageing
- Effective damping of vibration and noise
- Good electrical insulating properties
- High tear strength and mechanical durability
- Suitable for both indoor and outdoor applications
Bülte neoprene washers are ideal for sealing, vibration damping and insulating bolted joints. The sealing washers are available in a wide range of sizes for M3 to M20 metal and plastic screws.
EPDM Gaskets and Sealing Washers
EPDM (ethylene propylene diene rubber) is a versatile synthetic elastomer renowned for its outstanding resistance to weathering, UV radiation and ozone. Thanks to its excellent elasticity and ageing resistance, EPDM is widely used for flat gaskets, sealing washers and other sealing components in both indoor and outdoor applications. EPDM seals offer the following key benefits:
- Outstanding resistance to weathering, UV radiation and ozone
- Excellent resistance to water, moisture and steam
- Good ageing and wear resistance
- Resistant to many diluted acids and alkalis
- High flexibility and excellent elastic recovery
- Good resistance to many chemicals
- Low-maintenance and cost-effective sealing solution
- Good electrical insulating properties
EPDM gaskets and sealing washers as well as foam washers made from EPDM are available on request.