O-ring Expansion

[jmjmjmjm]

Good Day,

i have a problem regarding the O - ring of our Transfer Pump of Spent Caustic unit. the O - ring expanded that caused to break the Mechanical Seal of the said Pump. the o - ring material was EP( Ethylene Propylene) and i checked that the chemical components of the spent caustic is compatible to the said material of the O - Ring. any other factor that may be the caused of o - ring expansion.

thank you and have a nice day.

 

[kendan]

A combination of heat and the spent caustic as well as any contaminants (if any) it comes into contact with could cause the material to swell. What is the maximum temperature this unit sees? Is there any contact with oils?

 

[nestorberasain]

I agree with the observation of kendan, EPDM is suitable for caustic soda but not for oil that may be contained in the "spent caustic".
I recommend you use an o-ring of CR or FKM, both are suitable for both fluids.