SEALING CRYOGENICS SS004
Cryogenics are identified as extremely cold fluids that seldom present a corrosion problem, but do present at least five other problems to mechanical seals:
- The product is too cold for an O-ring or any other type of elastomer.
- Many cryogenic fluids are non-lubricants. A special carbon graphite seal face is used in these applications that has some organic material embedded in the mixture that will release the graphite to provide a lubricating film.
- Cold fluids freeze the moisture in the atmosphere outboard the seal and restrict the seal movement.
- The seal faces must be dried prior to installing the seal, or any lubricant or moisture on the faces will freeze.
- The cryogenic is often dangerous.
|Applying an environmental control that would heat the cryogenic fluid would not be sensible.|
A tandem metal bellows seal application with an anti-freeze type barrier or buffer fluid is your best bet.
The bellows seal will allow you to eliminate all elastomers from the application.
|The bellows seals can be sleeve mounted with stainless steel gaskets to eliminate all elastomers and plastics|
You can choose between rotating and stationary bellows, but be sure whichever one you choose has adequate vibration damping installed to prevent “slip stick” vibration problems.