Fisherr 2100 Pneumatic and 2100E Electric
Liquid Level Switches
Fisher 2100 on-off pneumatic switch and 2100E
electric switch sense (shown in figure 1) high or low
liquid levels. Typically, these switches pneumatically or
electrically operate safety shutdown systems for field
processing equipment in oil and gas production
applications. 2100 and 2100E switches both use a
displacer‐style sensor located in an external cage that
mounts on the outside of a vessel.
Unless otherwise noted, all NACE references are to
n Proven Rugged Construction—The switch is isolated
and sealed from the process through a
corrosion‐resistant displacer and torque tube
assembly for maximum reliability. The displacer can
withstand up to 1‐1/2 times the maximum working
pressure, allowing it to remain in the cage during
n Sour Service Capability—Materials are available for
applications handling sour fluids and gases. These
constructions comply with the metallurgical
requirements of NACE MR0175‐2002.
Environmental restrictions may apply.
n Application Versatility—The 2100 and 2100E switch
construction comes in a left‐hand as well as a
right‐hand mounting version. The explosion‐proof,
hermetically sealed 2100E switch is offered as both
a factory mounting and as an electric switch retrofit
to the proven 2100 switch.
FISHER 2100 PNEUMATIC LIQUID LEVEL SWITCH
n Installation Versatility—The displacer cage has two
1 NPT pipe plugs that you can remove and relocate
for horizontal instead of vertical equalizing piping,
or for installation of a bleed or drain valve.
n Easy Reversibility—Switching action for both the
2100 and 2100E switches is field‐reversible from
high‐level to low‐level or vice versa without
2100 and 2100E Level Switches