Seal Certification - Emerson Fisher L2e Instruction Manual

L2e Controller
June 2022

Seal Certification

The L2e instrument is not dual-seal certified. However, the enclosure is not exposed to process pressure during normal
operation, and is vented, as shown in 6. The process seal is contained in the separate mechanical sensor which can be
separated from the L2e enclosure without disturbing the process connection. A process seal failure will result in
process fluids being exhausted through the L2e enclosure vent, with an accompanying decrease in enclosure pressure
from the operating process pressure. Thus annunciation of a process seal failure is provided. The switch component,
which is separately sealed from the L2e main enclosure volume by a metal cap, is never exposed to full process
pressure even in the event of process seal failure.
Figure 6. Schematic
PROCESS PRESSURE
10
VESSEL
PROCESS
MEDIA SEAL
INSTRUMENT ENCLOSURE
Controller housing vent is designed to drop
SENSOR
maximum process pressure to less than 6.9 bar
(100 psig) at switch in event of primary seal failure
DETAIL
Instruction Manual
SWITCH
VENT
Certified Single Seal Device
Maximum seal pressure: 6.9 bar (100 psig)
Seal Temperature: ­40 to 204°C (­40 to 400°F)
D103531X012