Nitrile degradation

[engsup]

I have nitrile lined braided stainless steel hoses for an indoor compressed air system. The compressed air is at 40 deg C, and 8 bar. Design pressure for the hoses is 95 bar. The nitrile lining has suffered severe throughwall circumferential cracking in this environment in only 30 months. Is it reasonable to expect such apparently accelerated degradation? Ageing? Defective material? Aggressive environment? Excessive bending?
Thanks

 

[cnr]

In general there is two basic liner for air hose :Nitrile and EPDM, here is the plus an minus of the different materials
Nitrile: has a good oil resistance, poor aging and ozone resistance
EPDM: has good aging caracteristic, good heat resistance,good ozone resistance,poor oil resistance.

Most likely you have a nitrile because oil is added in the air , if you don`t then EPDM should be a better choice.
CNR