INSTALLATION
CLEARANCE
Make sure there will be enough mom to easily mount the
sight pipe, flame detector, and all required accessories, and to
remove th e
flame
detecto r for troubleshooting and servicing.
INSTALLING THE SIGHT PIPE
Thelocationofthesightpipeisthemostcriticalpartofthe
installation. A
in. black iron sight pipe is recommended.
Do
a stainless steel or galvanized pipe because its
internal surface blackens with use as deposits from the
combustion chamber accumulate on it. Initially, its shiny
intemalsurfacereflectsinharedradiation, whichcouldresult
in a satisfactory flame signal even though the pipe may be
improperly located. As it blackens, less
radiation is
reflected and the
signal becomes marginal.
Because no two situations
the same, the length and
sighting angle of the pipe must be determined at the time and
placeofinstallation.Generally,itisdesirabletohavethesight
pipe tilting downward to prevent soot or dirt buildup.
PREPARE HOLE IN WALL OF COMBUSTION
CHAMBER
Form a hole of the proper diameter for the sight pipe in the
the
hole (Fig. 9) to leave room for small adjustments of the
sighting angle. The taper of the hole should be about 1 in. for
every 3 in.
mm for every 76.2 mm] of wall thickness.
INSTALLING ACCESSORIES
It may be necessary or desirable to install accessories
between the sight pipe and the detector. This section
scribes the installation of these accessories.
SIGHT PIPE VENTILATION
may be necessary to ventilate the sight pipe to cool the
detector.
For a negative pressure combustion chamber, drilling a
few holes in
section of the sight pipe outside of the
combustion chamber allows air at atmospheric pressure to
flow through the sight pipe into the chamber. A perforated
pipe nipple between the sight pipe and the flame detector can
also be used. See Fig. 7.
For a positive pressure combustion chamber, connect a
supply of pressurized air from the burner blower to flow
throughthesightpipeintothechamber.Theairpressuremust
be greater than the chamber pressure.
Fig.
air
cooling.
mounting details, refer to form 60-0361 for the 118367A
Swivel Mount)
REDUCER BUSHING
To mount the detector on a
in. sight pipe,
if replacing a
lead
detector,
install a
Reducer Bushing (Fig. 1).
PLATE
To reduce the detector field-of-view, and restrict it to the
intersection of the pilot and main flame, or to a small area of
hotrefractory (see Fig. install a 105 134 Orifice Plate. The
plate can be inserted into a standard
in. pipe
coupling (Fig. 1) or into the seal-off adapter, if used.
MOUNTING SIGHT PIPE
Thmadoneendofthepipetofitthemountingcollaronthe
detector (or an accessory, if used, see Fig. 1). Cut the pipe to
the desired length (as
practical). T o
avoid conducting
excessive heat back to the lead
photocell, the sight
pipeshould not extendmore than halfway
into
the refractory.
Tack weld
pipe to the wall in a trial position (Fig. 9)
.
Do
permanently weld the sight pipe in place until ajter
completing the Adjustments and Checkout, page 10.
NOTE: If you use a Swivel Mount (part no.
and
yo u
arepositive
about the location and sighting angle, you
can permanently weld the pipe.
PIPE NIPPLE
A in. pipe nipple, 6 to 8 in. 152 to 203 mm] long, can
be inserted between the sight pipe and the
Mount
(Fig. to help cool the lead
cell. Usin g
the
pip e
nipple
will also reduce the viewing area of the detector, see Table 2
or 3).
SEAL-OFF ADAPTER
To protect
detector from hot gases, install a 105 172A
Seal-Off Adapter (Fig. 1). The adapter has a glass window
that prevents hot gases from reaching the lead sulfide
cell.
HEAT BLOCK
To insulate the detector from sight pipe temperatures
above 125” F
install a 105061 Heat Block (Fig. 1).
The device is made of nonheat-conductive, laminated plastic
that prevents heat
being conducted from the sight pipe
to the detector. It can withstand temperatures up to 250” F
DETECTOR PIPE NIPPLE
PIPE TEE
SIGHT
PIPE
MOUNTING THE DETECTOR
Before mounting the
install the lead sulfide
photocell (if not installed already).
COOLING AIR
APPLIED UNDER
Unscrew the bushing from the cap, plu
g
the photocel l into
the
cell mount, and screw the bushing back into the cap (Fig.
8). The bushing also includes a
lens to
available radiation on the photocell face.
Mount the
Detector onto the sight pipe, heat
block, orotheraccessory (Figs. 1 and 9). Screw the mounting
collar onto the sight pipe or accessory.
SWIVEL MOUNT
To facilitate flame sighting, a Swivel Mount (part no.
is available. The Swivel Mount requires a reducer
of the proper size to mount it onto the sight pipe. (For
8