Extension Pieces (2) | Auger with Carbide Tip | Wire Brush | Fig. # 8154.0 |
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TUBE CLEANING PROCEDURE
Establish a regular inspection schedule, frequency depending on local water condition and severity of service. Do not let the tubes clog up solidly. Clean out deposits over 1/16" in thickness.
The heater may be cleaned from the return header side, without breaking pipe connections. It is prefer- able, however, to remove both headers for better visibil- ity through the tubes and to be sure the
Note that you do not remove the top panel or the heat exchanger, generally.
After reaming, mount the wire brush in place of the auger and clean out debris remaining in the tubes.
Another method is to remove the heat exchanger, ream tubes and immerse heat exchanger in
TUBE REPLACEMENT PROCEDURE
On Raypak units, tube replacement may be ef- fected without rolling, as a temporary means of repair, providing there are two or more tubes rolled in to act as stays on the left and right sides. The "O" rings should provide a seal up to 125 PSI working pressure. Use 3/ 8" heavy duty reversible drill motor or large to power the tube roller. If a reversible drill is not available, after rolling the tube in, remove the drill motor and wrench out the roller. A tube roller is available from the factory.
Shut gas and power off to the unit, close the system off and drain the heater. Remove the draft diverter. Remove the access panel and jacket top. Lift flue collector off. Remove "V" baffles over tube(s) to be replaced. If no pipe unions have been provided, use the header as a union, remove the flange nuts off the inlet- outlet header, break gas connection and slide heater away from piping to allow room to work. Pull wedge clips out of control wells and remove sensing bulbs. Remove flange nuts of the return header and remove header. Lift heat exchanger straight up and inspect "O" ring seals at this time. Unless severed they are reus- able. The tube may be cut out the a hacksaw or hammer and chisel adjacent to both tube sheets, leaving studs in the tube sheets. Then proceed to collapse studs in the tube sheets with a chisel or screwdriver. Use caution not to cut into the tube sheet. Replacement tubes will have the fins stripped off longer on one end. The long end is inserted into the opening of the tube sheet first; then the short end is fitted through the opposite tube sheet. If the tube ends become dented or bent, straighten at least (4) inches back from the tube and by means of a tapered punch.
Insert tube roller into tube opening up to stop against tube, then push center rod in until roller is tight. Be careful to keep replacement tube squared up 1/8"
outside each tube sheet. A loose tube will sometimes pull toward the roller. Attach drill motor to tube roller, holding it straight and level. Proceed to expand tube until the tool begins to grab. At this point, 1/2" to 1" should be exposed on the tool shank. Reverse drill motor or wrench out by hand. Care should be exercised to avoid applying excessive torque during rolling opera- tion and to avoid thinning out any part of the tube wall excessively over .015". Use same procedure at the opposite end of the tube.
Apply line pressure test, and
DESOOTING PROCEDURE
CAUTION: SOOT IS COMBUSTIBLE. EXERCISE EXTREME CARE. NEVER USE A WIRE BRUSH.
Soot can clog areas between fins and cause even- tual tube failure. Any sign of soot at the base of the burners or around the outer jacket indicates a need for cleaning.
1.Disconnect top portion of unit. (See heat exchanger
removal procedure steps 1 through 6).
2.Remove burner tray (See burner tray removal procedure.)
3.Take a garden hose and wash heat exchanger, making sure soot is removed completely from be- tween fins. Avoid excessive water against refrac- tory.
NOTE: In extreme cases it may be necessary to re- move the heat exchanger completely for cleaning. The simplest method is steam cleaning at the local car wash. DO NOT WIRE BRUSH.
COMBUSTION CHAMBER REMOVAL
1.Remove heat exchanger (See heat exchanger removal procedure).
2.Lift up and remove front and rear refractory shield.
3.Remove refractory panels.
4.Reverse above procedure to
Fig . # 8155.0s
Refactory Panel Top View
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