Faces for cryo operation and elastomer choice

[sellosargentinos]

I am trying to find out wich are the best mechanical seal faces for a single seal in cryo aplication, at very high rpm.
Original faces come as metal ( i don't know wich one) and something else, that seems to be carbon , but i am not sure, becouse is painted blue. Does anyone know anything about it ?.
Also, what can i use as elastomer ??....energized spring seals or orings ?

thank you

 

[msouza]

Carbon x Silicon Carbide is a good options, since the Silicon Carbide can run better than Tungsten Carbide under extreme temperature conditions (and its possible variantions), SC is less sensitive than TC concerning temperature variations. For gaskets an special Parker Buna compound can be founf easily, but it is necessary to know exactly what temperature you are talking about. Energised O-Rings are also a good choice but ir tends to be more expensive and calls for a more careful handling and operating.

Hope it helps.

Regards

Mario Souza
Application & Product Engineering
WMF Solutions Brazil

http://www.wmfsolutions.com

 

[msouza]

This is the propective compound...

Parker V1289-75 can be used until -55°C. This is also known as Cryogenic Buna or Nitrile.

Mario Souza
Application & Product Engineering
WMF Solutions Brazil

http://www.wmfsolutions.com

 

[sreid]

Since you mentioned High Speed, you might want to look at Ferrofluid seals.

http://www.ferrotec.com/products/fe...89e0093f0bda&gclid=CMr4utvanpUCFQ89awodp37ikw

 

[bk19702]

SC is very susceptible to catastrophic failure from thermal shock, so I would be careful about applications with rapid swings in temperature.

Have you considered a non-contacting seal cryo-seal for the application? They will last 5 - 10 times longer than a contacting seal, depending on the application specifics. What RPM are you looking at?

 

[flexibox]

Have a look at the John Crane Type 285 seal specifically designed for these applications.

 

[sellosargentinos]

Thank you very much to all for your answers. The client has a Sundine mechanical seal. I repaired it, but it didn't work very good. I have checked the quality of lapping, and all i can think is that the problem is the material of the faces. I have used carbon graphite fenol resin impregnated against 420 ss hardened.

 

[flexibox]

Sounds like you do not know what you are doing. Do not play with this product as you must consider the safety of others

 

[bk19702]

Wow. I would not dabble with doing your own repairs on a cryo seal, especially if you are not familiar with any kind of seal repair or material requirements. Get the seal rep involved. I did not want to mention the seal by name, but the T-285 is an excellent choice for cryo applications.