Emerson Exchange 365

Hi Robert,

The primary concern for high temperature / hard vacuum applications is to make sure that the internal oil fill of the pressure transmitter / remote seal assembly does not vaporize.  In order for the pressure transmitter to remain functional, the oil fluid needs to remain in a liquid state.  Operating a pressure transmitter in a vacuum state will lower the boiling point of a fill fluid. 

Specifics on your questions:

• Emerson does offer Rosemount pressure transmitters with remote seals that have specialty fill fluids that can handle 450F at 10 Torr
• The wetted components that will come in direct contact with the process should be chosen based on chemical compatbility with the process regardless of vacuum or temperature conditions. 

Below is a link to a white paper you may find helpful on specifying and operating pressure technoloy under vacuum conditions. 

http://www2.emersonprocess.com/siteadmincenter/PM%20Rosemount%20Documents/00840-0100-4016.pdf

Thanks,

Michael