Explosion protection
5.2 FM
SITRANS SL
80
Operating Instructions, 12/2010, A5E01132948-04
Materials in the sensor pair
The sensor pair (transmitter and receiver) is built mainly using stainless or surface treated
steel and aluminium 231 (maximum magnesium content 0.5%). The O-rings and gaskets
used are made of FKM (fluoro polymer) or FFKM (perflour elastomer). The process interface
window is a made of borosilicate glass and contains an O-ring made of FKM. In the case that
gas purging of the sensor fails the O-rings will be the limiting component for the temperature.
They can withstand 215 °C/420 °F (FKM).
Pressure Safety
In some applications the process can be overpressurized. Normally this is not a situation
where the measurements will be adequate.
WARNING
The high pressure glass in the sensors must not be subject to any mechanical impact which
might cause damage to the glass (scratch, gash etc.). Only use a soft cloth for cleaning of
the glass. Make sure that it is safe to dismount the sensor before cleaning.
WARNING
Make sure all plugs and tube fittings are sealed with the enclosed pipe thread Sealant
(Swagelok MS-PTS-6). (Instructions given on the sealant tube must be carefully followed).
Approval
The concept of the FM approval is that the system is not modified and that special FM
approved cables and bushings are used. An absolute condition for the approval is that the
equipment is set up according to FM system set-up (Page 82).
Liability
Following commissioning, the total responsibility is with the owner.