elastomer packing under compression for HNBR material

[yudhichen]

Dear all,

I'm trying to design packing with HNBR material for wrap around casing hanger wellhead equipment.

I need to check out if the packing wont extrude under 10,000PSI differential pressure after it being compressed.
The limitation that i made is how much axial distance (d) packing can be compressed
and how much load (F) the packing shall be subjected to compress.

any useful parameter that i can refer to on below to ensure no extrusion on the packing.
I saw every vendor always mention below parameters for comparison:
a. tensile strength at break
b. ultimate elongation
c. shore A hardness
d. 100% modulus
e. compression set % at certain temperature

Appreciate any insight.

Thank you

Yudhi

 

[johnnymat]

the parameters you listed are important for determining if the material will extrude at high pressure, the stiffer the better, which also means it will be hard, 90 IRHD +, but at this hardness and high stiffness, the elongation may not reach 100%, so you should also look at Modulus at 50%.

The property data you gather from data sheets will all have been tested at room temperature, so you should also consider the temperature in application and see if you can obtain property data when tested at that temperature. You will find this very difficult to obtain, suffice to say that all these mechanical properties will be significantly worse at elevated temperature.

johnnymat