Hydraulic seals
The perfect solution for direct contact with fluids

A hydraulic sealing system is combined with several sealing elements:

• The scraper keeps dirt and moisture out, keeping the system clean.
• The guide element prevents metal-to-metal contact and stabilizes the piston and rod.
• The rod seal seals the rod side against fluid leakage.
• The O-ring seals the components statically against oil loss.
• The piston seal separates and seals the oil chambers from each other and prevents overflow.

The interaction of all elements ensures that the hydraulic cylinder is sealed, the hydraulic system remains clean, and functionality is thus guaranteed.

Yes. Since ttv sealing systems consist of various elements, these can also be combined in different variants and profiles. This allows the entire sealing system to be individually adapted to your application.

Examples: A sealing system with NBR elements can be adapted to the conditions when used at higher temperatures with FKM and PTFE materials. Or, when used in other fluids such as PAGs or ATFs, the materials must be selected according to media resistance and the temperature range of use.

Common sealing materials in hydraulics:

• Piston and rod seals made of PU + NBR
  → Established for decades and therefore available in a wide range of dimensions. Can be manufactured cost-effectively from series tools using proven technologies.
• Grooved rings and roof sleeve seal sets made of rubber-fabric materials
  → Robust sealing elements for high-pressure plunger pumps, steering systems, and drives for container ships, use in steelworks, special applications.
• Scrapers made of NBR or PU, also with metal inserts
  → The right scraper for every application and installation space

The choice of the right seal depends on the respective requirements, such as the pressure range and operating temperature in conjunction with the pressure medium used, such as mineral oil, HFA or HFC oils, PAGs. In addition, the speeds driven with long or short strokes and, if applicable, the pressure peaks must be taken into account.

Piston and rod seals

• For linear movements in cylinders, lifting and pulling movements
• Materials: NBR/PU/PTFE for standard applications, FPM, HNBR for higher temperatures or special media
• Pressure up to 70/80 MPa
• Temperature depending on material:
• PTFE: –40 °C to +200 °C depending on the preload element
• NBR/PU: –35 °C to +100/+110 °C
• FPM: up to +200 °C

Rotary seals

• For rotating or swiveling shafts (rotary distributors)
• Double-acting, 0.2 to 1 m/s
• Material depending on design
• Temperature up to +200 °C, pressure up to 40 MPa

Complete piston

• Ready-to-install solutions for pneumatics and hydraulics
• Pneumatics up to 1.6 MPa (dry/oil-free with initial lubrication)
• Hydraulics up to 5 MPa
• Materials: NBR or FPM

RSS roof flashings

• For extreme applications in presses, steelworks, mining, or steel hydraulic engineering
• Pressure up to 60 MPa
• Material: NBR + fabric-reinforced NBR with POM support rings

The choice of material determines how resilient or resistant a seal is to pressure, temperature, wear, and media.

Basic material properties:

• NBR (nitrile rubber): standard, high compressive strength, good sliding and abrasion properties
• HNBR: better at higher temperatures and with oil-containing media
• FPM (FKM): very resistant to high temperatures and aggressive media
• PU (polyurethane): extremely abrasion-resistant, ideal for dynamic loads
• PTFE: very low friction, wide temperature range, chemically resistant
• TPE: flexible and robust, universally applicable
• Metal reinforcements: e.g., in scrapers for stability and a secure fit in the installation space

Depending on the seal type:

Piston and rod seals / groove rings
→ often PU or PTFE when high dynamics or low friction is required

Scrapers
→ typically NBR, PU, TPE, or PTFE, depending on the environment and contamination

Roof sleeve seal sets
→ rubber-fabric material and POM or PTFE support rings

ttv tip:
The sealing system can be designed with different variants and materials, allowing its properties to be specifically adapted to the task at hand.

Scrapers are an essential component of hydraulic cylinders. They prevent contaminants such as dirt or moisture from entering the hydraulic system from outside.

Scrapers in hydraulic seals by material:

• Standard applications: PU, NBR
• Dynamic applications with high loads, e.g., in construction and agricultural machinery → PU

Applications with high speeds, low friction, wide temperature ranges, or chemically aggressive media → PTFE (polytetrafluoroethylene)

Single-acting hydraulic seals only seal in one direction. They are therefore useful when the pressure only acts on the seal from one side. Alternatively, two seals can be used to seal in both directions.

Double-acting hydraulic seals seal in both directions. They are used when both push and pull movements in a cylinder need to be sealed equally securely.

Guide elements absorb lateral forces and are designed to prevent metal-to-metal contact between pistons and rods and the housing. 

Our recommendations:

ttv-5640 (green):

• For lubricated hydraulic components, even with dry running
• Very low friction, high sliding properties
• Temperature range: –60 °C to +200 °C
• Sliding speed up to 15 m/s
  
  

Suitable for applications with high demands on smooth running and energy efficiency, where low friction and high speed are paramount.

ttv-9200 (turquoise):

• For heavy-duty hydraulic cylinders with high pressure loads
• High compressive strength, resistant to transverse forces
• Temperature range: –60 °C to +120 °C
• Sliding speed up to 1 m/s

Suitable for heavy industrial hydraulics and cylinders with high side forces, where maximum stability and pressure resistance are required.

We use only the highest quality materials and are able to design every hydraulic seal to fit your application perfectly – whether it involves high temperatures, aggressive media, or extreme pressure:We adapt the design and material to your requirements.

• We work with a wide range of materials such as NBR, PU, PTFE, and FPM.
• We advise you based on our experience in many industries and applications.
• We also pay attention to cost-effectiveness and ensure long service life with high product quality.