Honeywell C7015A Clearance, Prepare Hole in Wall of Combustion Chamber, Installing Accessories

C7015A

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 flame detecto for troubleshooting and servicing.

INSTALLING THE SIGHT PIPE Thelocationofthesightpipeisthemostcriticalpartofthe

installation. A 3/ 4 in. black iron sight pipe is recommended. Do rwt use 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 inhare dradiation is reflected and the flam e signal becomes marginal.

Because no two situations a m 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 walioftbecombustionchamberattheselectedlocation.Flare 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. 125. 4 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 de- scribes the installation of these accessories.

SIGHT PIPE VENTILATION

It may be necessary to ventilate the sight pipe to cool the detector.

For a negative pressure combustion chamber, drilling a few holes in th e 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. 7-Forced air cooling.

DETECTOR	PIPE NIPPLE	PIPE TEE	SIGHT
			PIPE

+@a

COOLING AIR

APPLIED UNDER

SWIVEL MOUNT

To facilitate flame sighting, a Swivel Mount (part no. 118367A ) is available. The Swivel Mount requires a reducer of the proper size to mount it onto the sight pipe. (For

mounting details, refer to form 60-0361 for the 118367A Swivel Mount)

REDUCER BUSHING

To mount the detector on a l/ 2 in. sight pipe, speci&zlly if replacing a FireyeW lead sulfuie detector, install a 390427 AReducer Bushing (Fig. 1).

ORIFICE 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. 3), install a 105 134 Orifice Plate. The or&e plate can be inserted into a standard 3/ 4 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 short as practical). T avoid conducting excessive heat back to the lead sulfide photocell, the sight pipeshould not extendmore than halfway into the refractory.

Tack weld the pipe to the wall in a trial position (Fig. 9) Do . not 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. 118367A ) and yo u arepositive about the location and sighting angle, you can permanently weld the pipe.

PIPE NIPPLE

A 3/ 4 in. pipe nipple, 6 to 8 in. [ 152 to 203 mm] long, can be inserted between the sight pipe and the C7015 A Mount (Fig. 1) to help cool the lead sulfid e cell. Usin gthe pip enipple will also reduce the viewing area of the detector, see Table 2 or 3).

SEAL-OFF ADAPTER

To protect the 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 photo- cell.

HEAT BLOCK

To insulate the detector from sight pipe temperatures above 125” F [52” Cl, install a 105061 Heat Block (Fig. 1). The device is made of nonheat-conductive, laminated plastic that prevents heat hor n being conducted from the sight pipe to the detector. It can withstand temperatures up to 250” F [121 ° C].

MOUNTING THE DETECTOR ”

Before mounting the C7015A , install the lead sulfide photocell (if not installed already).

Unscrew the bushing from the cap, plu the photocelg intol the cell mount, and screw the bushing back into the cap (Fig. 8). The bushing also includes a focu&n g lens to concenuate available radiation on the photocell face.

Mount the C7015 A Detector onto the sight pipe, heat block, orotheraccessory (Figs. 1 and 9). Screw the mounting collar onto the sight pipe or accessory.

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