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Rosemount 3051S with 1199 diaphragm system approved for Cryogenic applications?


Does anyone have experience using the 3051S DP pressure transmitter together with the 1199 seal diaphragm system in cryogenic applications?

I am considering using this type of solution for level measurement in cryogenic service when compared with a traditional 3051S differential pressure and purge system installation.

Best Regards.

3 Replies

  • Hi Cristobal,

    Cryogenic liquids are too cold to measure by direct contact with a remote seal or pressure transmitter. Impulse piping is used to allow the liquid to vaporize into a gas and the warmer gas is allowed to contact the sensing element.

    1. Install impulse piping horizontally from the lower process tap.
    2. Run the impulse pipe upwards at about a 30-45 degree angle run for about a foot and install the sensor/remote seal. This will create a vapor barrier between the sensing diaphragm and the liquid.
    3. If there is a top process tap install impulse piping horizontally from the tap.
    4. Run the impulse pipe upwards at about a 30-45 degree angle for about a foot and then install the remote seal.  If this is a wet/dry leg, run the impulse piping down to the transmitter after the upward incline.

    If you would like to use remote seals, you can enter information about your application in Instrument Toolkit to determine the Total System Error.


    Cryogenics Level.pdf

  • In reply to Ian Kugel:

    Thanks for the reply Ian.

    Would a purging system be necessary?
    If so, what considerations would be necessary for the purging system of the impulse lines?

  • In reply to Cristobal Ruiz:

    Hi Cristobal,

    As long as the installation is setup as described with a moisture collection pot, there should not be any need to purge the lines. Typically, with the setup as described, remote seals are not used, just impulse lines.

    I wanted to note that Syltherm XLT is an available fill fluid for the 1199 remote seal. With it, the sensing element can be in direct contact with the process if the process temperature does not exceed the temperature limits of the fill fluid. The temperature limits of Syltherm XLT are -157 to 293 deg F (-105 to 145 deg C). Typical cryogenic applications usually exceed those temperature limits.