A X-ring is a double-action sealing element for either static or dynamic applications and has an x-shaped profile with four sealing lips.
- radial - dynamic applications
- axial/radial - static applications
X-ring
Fields of application
static
dynamic
single acting
double acting
Linear
Rotating
oszilating
Main use
for static and dynamic applications, its design prevents a twisting of the cord
Materials
elastomers
Advantages
- extremely versatile, also in dynamic applications
- greater stability as O-rings
- no twisting in the groove
- long service life
- lubricant reservoir between the sealing lips
- lower friction compared to the O-ring
- parting line outside the sealing area
Fields of application
X-rings are used in a wide variety of technical application fields. Compared to the O-ring, the X-ring can be used better for dynamic sealing. Its range of application is limited by the respective pressure and speed.
Main fields of application:
- radial-dynamic sealing
- axial-static sealing
- radial-static sealing
Technical values
Materials
Pressure
static up to 40 MPa (from 5 MPa with Back-up ring)
linear up to 30 MPa (from 5 MPa with Back-up ring)
rotatory up to 15 MPa (from 5 MPa with Back-up ring)
linear up to 30 MPa (from 5 MPa with Back-up ring)
rotatory up to 15 MPa (from 5 MPa with Back-up ring)
Temperature
-30°C / +80°C (material dependent)
Speed
linear up to 0,5 m/s
rotary up to 2 m/s
rotary up to 2 m/s
Pressure
static up to 40 MPa (from 5 MPa with Back-up ring)
linear up to 30 MPa (from 5 MPa with Back-up ring)
rotatory up to 15 MPa (from 5 MPa with Back-up ring)
linear up to 30 MPa (from 5 MPa with Back-up ring)
rotatory up to 15 MPa (from 5 MPa with Back-up ring)
Temperature
-30°C / +150°C (material dependent)
Speed
linear up to 0,5 m/s
rotary up to 2 m/s
rotary up to 2 m/s
Pressure
static up to 40 MPa (from 5 MPa with Back-up ring)
linear up to 30 MPa (from 5 MPa with Back-up ring)
rotatory up to 15 MPa (from 5 MPa with Back-up ring)
linear up to 30 MPa (from 5 MPa with Back-up ring)
rotatory up to 15 MPa (from 5 MPa with Back-up ring)
Temperature
-20°C / +200°C (material dependent)
Speed
linear up to 0,5 m/s
rotary up to 2 m/s
rotary up to 2 m/s
Pressure
static up to 40 MPa (from 5 MPa with Back-up ring)
linear up to 30 MPa (from 5 MPa with Back-up ring)
rotatory up to 15 MPa (from 5 MPa with Back-up ring)
linear up to 30 MPa (from 5 MPa with Back-up ring)
rotatory up to 15 MPa (from 5 MPa with Back-up ring)
Temperature
-40°C / 130°C (material dependent)
Speed
linear up to 0,5 m/s
rotary up to 2 m/s
rotary up to 2 m/s
Maximum values temperature, speed and pressure are simultaneously not applicable! The values vary in dependence of material and media. For technical queries please contact our application consultants – we have the right solution for you.
Downloads
X-ring
Further to Square Ring
Definition of X-ring dimensions and ordering sizes
- inside diameter d1 from approx. 0,74 mm to 600 mm
- Cross section w from approx. 1,02 mm to 6,99 mm
Sealing effect
The sealing effect of the X-ring is the result of the axial or radial compression of the rings cross section when it is installed. Due to its profile and better distribution of the pressure, a high sealing effect is achieved. The system pressure additionally increases the pressure on the sealing surfaces.
Design Information
In general
For all applications, we recommend selecting the largest possible cross section in relation to the inner diameter d1 when selecting the cross section "w". If the tolerance is unfavorable, the next largest cross section should always be used. This applies in particular to dynamic applications.
Stretching/compression:
In dependence of the given application at a radial installation, X-rings can be:
- expanded by max. 6%
- compressed by max. 3%
Installation precompaction
Depending upon the application, the following values should be achieved:
- dynamic sealing 6 – 18%
- static sealing 8 - 25%
In order to achieve an optimum sealing effect, the contact surfaces must meet minimum requirements. The permissible roughness values must be adhered to, especially in dynamic applications.
Gap widths:
The permissible gap "S" is determined by the system pressure, the cross section and the hardness of the X-ring. If the sealing gap is too large, gap extrusion can damage the X-ring. The use of Back-up rings is generally recommended from a pressure of approx. 5 MPa. It should be noted that the groove width for the X-ring back-up ring combination must be enlarged.
X-ring as rotatory seal:
The X-ring can be used to seal rotating shafts in applications with short switch-on times. It should be noted that the inner diameter of the X-ring should be approx. 2% - 5% larger than the shaft diameter to be sealed.
Installation instructions
To exclude possible sources of error, ensure that the following points are observed for the sealing function when installing X-rings:
- defined insert inclinations, burr free, rounded-off transition,
- surface quality Ra < 0,4µm, Rz < 1,6 µm
- burr-free rounded-off holes and slits
- lubrication (without any solid additives)
- installation tools to pass over sharp edges and corners (e.g. threads)
- dirt-free sealing surface
- the X-ring must not be overstretched
- the X-ring must not be warped or twisted
Your contact person for
Technology - General sealing topics, special constructions
Mr. Andreas Raidt
Head of Engineering
Head of Engineering
Do you have any questions, ideas, or suggestions? We are more than happy to assist you with advice. In person, over the phone, or digitally.
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