Spectra watermaker o rings

[BrightAyes]

I am replacing the membrane on my Spectra Ventura 150 watermaker after ~ 6 years of use. I believe it would be prudent to replace the O rings on the ends of the membrane housing. I priced them from the local Spectra dealer and they want $29.00 plus tax and shipping for these 6 o rings. They appear to be 4mm x 58mm for the 2 big ones and 3mm x 19mm for the 4 smaller ones.

I can get o rings from my local industrial supply house for a fraction of the Spectra cost. Can anyone help me as to the material and hardness specs for these o rings. Buna-n, soft Buna-N, silicone, EPDM, Viton, etc.

Bright Ayes

[RockWoods]

I would think Buna or Viton would be Ok. Viton is a little tougher and more heat resistant, not an issue in your application. Silicon normally used for applications where the equipment may get quite hot.

[nimblemotors]

Is there anything wrong with them?
If not, why replace them with possible risk of the wrong ones?

[Fix]

Replace them only if you see cracks in them,
Otherwise,apply some silicone grease,and that's it