Query regarding a product:















EKasic® SILICON CARBIDE SEALS, ROTARY UNIONS

EKasic® SILICON CARBIDE SEALS FOR ROTARY UNIONS

Rotary unions allow liquids or gases such as hydraulic fluid, cooling lubricants or air to be fed from a stationary feed system into a rotating unit. For such challenging machine elements, we offer high-quality EKasic® SSiC gaskets (sintered silicon carbide). The high quality of the seals make them ideal for heavy duty applications, especially with contaminated and/or abrasive fluids. They are exclusively custom made by us to customers’ specifications.

The Key to High Speeds

EKasic® seals have a low specific density. It is between 2.80 and 3.20 g/cm3 depending on the material. Very high speeds of up to 50 000 l/min can achieved with very low density and maximum stiffness.

Specifications

EKasic® seals for rotary unions are available from an external dia. of 6 mm.

Typical Rotary Union Applications:

  • Machine-tool spindles
  • Continuous casting lines
  • Calenders for the paper industry
fileadmin/esk/plain/ekasic-e.html

Silicon Carbide
Material properties Norm Symbol/Unit EKasic®
F
EKasic®
F plus
EKasic®
C
Density DIN EN 623-2 ρ [g/cm3] >3.15 >3.18 >3.15
Porosity DIN EN 623-2 P [%] <2.0 <1.0 <2.0
Mean grain size [μm] <5 <5 bimodal
Grain size distribution [μm] 10-1500
Phase composition α-SiC α-SiC α-SiC
Vickers hardness DIN EN 843-4 HV 1 [GPa] 24.5 24.5 24.5
Knoop hardness DIN EN 843-4 HK 0.1 [GPa] 24.5 24.5 24.5
Young's modulus DIN EN 843-2 E [GPa] 430 430 430
Weibull modulus DIN EN 843-5 m 10 10 10
Flexural strength,
4-pt bending
DIN EN 843-1 σB [MPa] 400 550 400
Compressive strength σD [MPa] > 2500 > 2500 > 2500
Poisson ratio ν 0.17 0.17 0.17
Fracture toughness
(SENB)
Klc [MPa·m0,5] 4 4 4
Coefficient of
thermal expansion
DIN EN 821-1
20°C - 500°C α [10-6/K] 3.8 3.8 3.8
500°C - 1000°C α [10-6/K] 5.1 5.1 5.1
Specific heat at 20°C DIN EN 821-3 cp [J/g K] 0.69 0.69 0.69
Thermal conductivity
at 20°C
DIN EN 821-2 λ [W/mK] 130 130 130
Thermal stress
parameters
calculated
R1 = σB·(1-ν) / (α·E) R1 [K] 203 255 203
R2 = R1·λ R2 [W/mm] 26 34 26
Specific electrical
resistance at 20°C
DIN EN 50355 ρ [Ω cm] > 108 > 108 104-105



Silicon Carbide
Material properties Norm Symbol/Unit EKasic®
P
EKasic®
G
EKasic®
T plus
Density DIN EN 623-2 ρ [g/cm3] >2.76-
2.89
>3.10 >3.24
Porosity DIN EN 623-2 P [%] 10-14 <2.0 <1.0
Mean grain size [μm] <5 bimodal <2
Grain size distribution [μm] 10-1000  
Phase composition α-SiC α-SiC,
graphite
α-SiC,
YAG
Vickers hardness DIN EN 843-4 HV 1 [GPa] 24.5 24.5 22.5
Knoop hardness DIN EN 843-4 HK 0.1 [GPa] 24.0 24.0 22.5
Young's modulus DIN EN 843-2 E [GPa] 340 390 430
Weibull modulus DIN EN 843-5 m 15 15 15
Flexural strength,
4-pt bending
DIN EN 843-1 σB [MPa] 225 250 650
Compressive strength σD [MPa] > 2000 > 2200 > 2500
Poisson ratio ν 0.13 0.15 0.17
Fracture toughness
(SENB)
Klc [MPa·m0,5] 3 3.5 6
Coefficient of
thermal expansion
DIN EN 821-1
20°C - 500°C α [10-6/K] 3.8 3.8 4.1
500°C - 1000°C α [10-6/K] 5.1 5.1 5.3
Specific heat at 20°C DIN EN 821-3 cp [J/g K] 0.69 0.69 0.71
Thermal conductivity
at 20°C
DIN EN 821-2 λ [W/mK] 110 130 87
Thermal stress
parameters
calculated
R1 = σB·(1-ν) / (α·E) R1 [K] 152 143 306
R2 = R1·λ R2 [W/mm] 17 19 27
Specific electrical
resistance at 20°C
DIN EN 50355 ρ [Ω cm] > 108 104-105 103-105