High-temperature SCR/Charge-Air-Cooler Silicone Hoses

Shore Hoses

Further to our last blog on “when to choose FKM liner as opposed to FVMQ liner for your Silicone Hoses”, we did some additional testing to drive home the point.

We subjected the ASTM-sized stabs/buttons of Viton® (FKM) and Fluorosilicone (FVMQ) to heat-ageing cycles of:

  1. 24 hours at 230 degrees centigrade,
  2. Then, 2 hours at 270 degrees centigrade,
  3. Then again, 24 hours at 230 degrees centigrade,
  4. Then again, 2 hours at 270 degrees centigrade,
  5. Then again, 24 hours at 230 degrees centigrade,
  6. Then again, 2 hours at 270 degrees centigrade,

Herein, you can see the change in Physical properties of the 2 materials:

 

Testing Parameters Viton® (FKM) Fluorosilicone (FVMQ)
Change in Hardness (pts) +3 +6
Change in Tensile Strength (%) -5.02 -65.46
Change in Elongation (%) +19.84 -58.48

Therefore, please choose carefully between an FKM and an FVMQ liner, for your Silicone Hoses. The higher the temperature (above 230 deg C), the faster the degradation in Fluorosilicone (FVMQ).

Shore hoses

Note 
When the hose is reinforced with Polyester, it should be used at a maximum of +180⁰C.
When reinforced with 100% meta-aramid, along with specialty Silicone-rubber grades, a Fluorosilicone-lined or FKM-lined Silicone Hose can be used at higher temperatures.

Contact us for more information.