1.3
Mounting
The TUFFY II Liquid Level Switch is available with a 2"
NPT mounting bushing, a variety of flange mountings and
external cages for mounting outside of the vessel.
Caution:
This instrument is intended for use in Installation Category II,
Pollution Degree 2.
1.3.1 Mounting an NPT Tuffy
®
II
1. Apply either Teflon
®
tape or appropriate lubricant to the
mounting threads to prevent galling.
2. Engage the 2" NPT by hand to avoid damaging threads.
3. Using a pipe wrench, rotate the unit clockwise until threads
are tight in mounting. Ensure that the conduit entry points
down.
See Figure 2.
Caution:
The TUFFY II must be installed with the conduit connection
pointing downward to ensure correct switching action.
1.3.2 Mounting a Flanged Tuffy
®
II
1. Have proper flange bolting and gasket on hand.
2. Cut and remove plastic shipping straps.
3. Carefully align TUFFY flange raised face (cladding) with
the face of the vessel mounting flange. Slide the flange on
the control to the vessel mounting flange and align bolt
holes. Ensure that the conduit entry is pointing down.
See Figure 3.
4. Ensure that the flange gasket is seated properly. Install
flange bolts and nuts.
5. Tighten alternating flange bolts in a star pattern.
Caution:
The TUFFY II must be installed with the conduit connection
pointing downward to ensure correct switching action.
1.3.3 Mounting External Cage Tuffy
®
II
A typical TUFFY external cage installation is shown in
Figure 4
.
1. Install cage so that trappings are within 3° of vertical in all
directions. Check installation with a level.
2. Mount cage as close to vessel as possible to provide more
accurate level in cage. Long pipe runs may result in cooler,
denser liquid than that in the vessel and cause inaccurate
level in the TUFFY cage.
44-607 Tuffy
®
II Liquid Level Switch
5
Figure 2
NPT Mounting Orientation
Figure 3
Flanged Mounting Orientation
Figure 4
External Cage Mounting
Conduit Entry
(down)
Conduit Entry
(down)
CL
CL
CL
Pressure
Vessel
Shut–off
Valve
Safety
Check
Valve
Shut–off
Valve
Drain Valve
Switch
Actuation
Level
NPT
Conduit
Connection
CL
