U2 COMBINATION VIEWING HEAD AND SIGNAL PROCESSORS
17
66-2071—02
Fig. 9. Viewing head mounting example.
Fig. 10. Second vertical head mounting example.
Mounting Examples (applicable to both Fig. 7 and Fig. 8):
Due to the heat and electrical insulation requirements of the U2, it is highly recommended to use the Honeywell
locking coupler adapter and locking coupler accessories for mounting, attached directly to the U2. In order to
maintain the specified U2 temperature, the minimum distance to mount the U2 from the sight pipe is 2.3 inches
(5.8 cm), using the R-518-PT12/L and the R-518-CL12-HTG locking coupler. Cooling air should be provided via a
“Y” or “T” in between the locking coupler and the sight pipe to reduce conducted heat and to keep the sight
pipe and U2 lens clean of debris and dirt. Refer to the Mounting and Sighting section on purge air requirements.
For electrical isolation reasons, the purge air line should be installed using an insulating material, such as a
rubber hose, in between the purge air line and the viewing head. Note that an extension pipe may be required to
locate the U2 further from the burner front plate to avoid high temperatures.
2 (51) NPT NIPPLE TOE
M-701-2
SWIVEL MOUNT
R-518-CL12-PG
PURGE AIR COUPLER
AND R-518-PT12
INSULATING LOCKING
COUPLER ADAPTER
BURNER FRONT PLATE
M33524
R-518-CL12-PG
PURGE AIR COUPLER
AND R-518-PT12
INSULATING LOCKING
COUPLER ADAPTER
BURNER FRONT PLATE
OR WINDOWBOX
M33628
1 (25)
NPTF PIPE
FLANGE
(OPTIONAL)
