Most refrigerant fluids aren’t chemically compatible with the fluoro elastomers (FPM or FKM) material generally used for making sealing gaskets. So, for this kind of application, we recommend all pressure transmitters and pressure switches using fluoro elastomer gaskets should be in contact with the fluid. Which means using the following products:

• all low pressure transmitters XMLP (<10 Bar/100 psi) or pressure switches XMLR (<100 Bar/1000 psi) that use ceramic technology that need the internal FPM sealing gasket   XMLP. . . M. . . F, XMLP. . . G. . . F, XMLP. . . R. . . F, XMLR . . . G. . . .
• all pressure transmitters XMLP, XMEP and pressure switches XMLR that have a G1/4 fluid connection, for which the external sealing is done by a fluoro elastomer gasket    XMLP. . . . . . 1F, XMEP. . . . . . 1F, XMLR. . . 5.

In addition, all our high-pressure transmitters XMLP, XMEP (10 Bar/100 PSI or above) and pressure switches XMLR (100 Bar/ 1000 PSI or above) that have a metal pressure cell directly welded on the fluid connection, and have a conic fluid connection that doesn’t require for an external sealing gasket, eg. ¼”-18NPT, 7/16-20UNF, can be used with all types of refrigerant fluid. These are: XMLP. . . B. . .70, XMLP. . . B. . .90, XMLP. . . P. . .30, XMEP. . . P. . .30, XMLR. . . M. . . 6.

Also, the most popular fluid connection is 7/16-20UNF-2A (Male), or 7/16-20UNF-2B (Female) in heating, ventilation and air conditioning applications (HVAC).