6
4.
Mount scanner sight pipe by either:
— Centering a Fireye No. 60-1664-3 (NPT) or 60-1664-4 (BSP) swivel mount over the hole
and installing the sight pipe on the swivel mount,
or
— Inserting the end of the sight pipe into the hole, aligning the pipe to the desired viewing
angle and tack weld. (Welding must be adequate to temporarily support the weight of the
installed scanner). The sight pipe should be arranged to slant downward so that the dirt and
dust will not collect in it.
FIGURE 5.
5.
When a satisfactory sighting position has been confirmed by operational test, (see section on
alignment), the sight pipe should either be firmly welded in place or, if the swivel mount is used,
the base position should be secured by tightening the three hex head cap screw located on the
swivel mount ring. In certain older style swivel mounts, tack welding may be required.
6.
Excessive flame signal can affect flame discrimination and prevent the control connected to the
scanner from performing properly. To reduce the signal level of the tube, or improve flame dis-
crimination, orifices may be installed to decrease the scanner’s field of view and reduce its sen-
sitivity. Installation of the orifice disk is shown in Figure 11.
7.
The scanner viewing window must be kept free of contaminants (oil, smoke, soot, dirt) and the
scanner temperature must not exceed its maximum rating. Both requirements will be satisfied by
continuous injection of purge air.
The scanner mounting may be made with provision for purge air through the 3/4” opening as shown
in Figure 6, Item A or C, or through a 1" tee/wye connection as shown in Figure 6, Item B. Normally
only one of the two connections is provided with purge air and the other is plugged. When a Fireye
coupling is used as shown in Figure 6, the 1" tee/wye connection is used for the purge air (plug 3/4”
opening).
Under normal temperature conditions, with clean burning fuels and moderate ambient temperature
conditions, purge air flow of approximately 4 SCFM (113 L/min) is generally adequate. A 0.1 psig
positive pressure difference between the atmosphere and boiler pressure measured at right angle to
the purge air flow, should result in a purge air flow of 4 SCFM. Up to 15 SCFM (425 L/min) may be
required for fuels that may produce high levels of smoke of soot or for hot environments to maintain
scanner internal temperature within specifications.
NOTE: The maximum viewing field of the lens is one inch per foot. Do not use more than one foot of
one inch sight pipe. Increase sight pipe diameter one inch for every additional foot of sight pipe
length used, to avoid restricting the scanner’s field of view. Temperature in the scanner housing
should not exceed those temperature limits listed in the specifications. Excessive temperatures will
shorten scanner life.
BUT THIS
NOT THIS
NOT THIS
FLAME MUST COMPLETELY COVER SIGHT OPENING
WARNING: Sighting position of the flame scanner should insure that the scanner does not
respond to the ignition spark.
