Raypak P-4001 Combustion Chamber Removal, Control Well Replacement, Tube Replacement Procedure

Combustion Chamber Removal

To remove the combustion chamber you must first have removed the heat exchanger. Unbolt metal com- bustion chamber retainer from top and remove combustion chamber panels individually.

Fig. 36: Refractory Panels—Top View

Control Well Replacement

Remove top, sensing bulb and clip. Collapse well tube at the open end and with a chisel, push through into the header, and remove the well through header. Insert a new well and roll into place. If a roller is not available, solder the well in place with silver solder.

Immersion Well

Fig. 37: Immersion Well

Tube Replacement Procedure

On Raypak tube replacement may be affected without rolling, as a temporary means of repair, provided there are two or more tubes rolled into act as stays on left and right sides. The "O" rings should provide a seal up to 125 PSI working pressure. Use a 3/8" heavy duty reversible drill motor or larger, 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 pool heater. Remove draft diverter. Remove the access panels and jacket top. Lift the

canopy and flue collector off (on models 926-1826, remove the canopy hold-down brackets). 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 pip- ing, allowing room to work. Pull wedge clips out of control wells and remove sensing bulbs. Remove flange nuts from the return header and remove head- er. Lift heat exchanger straight up and out.

Heat exchanger header o-rings must be replaced with new ones. The tube may be cut out with a hack-saw or hammer and chisel adjacent to both tube sheets, leav- ing stubs in the tube sheets. Then proceed to collapse stubs 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 fit- ted through the opposite tube sheet. If the tube ends become dented or bent, straighten at least four (4) inches back from the tube end 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" out- side each tube sheet. A loose tube will sometimes pull toward the roller. Attach drill motor to tube roller, hold- ing 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 re-roll, if necessary, before replacing canopy.

Procedure For Cleaning Flue Gas Passageways

Soot can clog areas behind fins and cause eventual tube failure. Any sign of soot at base of burners or around outer jacket indicates a need for cleaning.

1.Lift off draft hood and flue collector by removing bolts and screws.

2.Remove "V" baffles from heat exchanger.

3.Remove burner tray.

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