Hot Water Generator Installation and Operation Manual
6Maintenance
10.Install a new gasket on the manway or hand hole to prevent any possible leaks. Tighten the gasket properly to prevent leaks. Caution: Over tightening can result in cutting the gasket and allowing a water leak to occur.
11.Replace the jacket cover over the manway or hand hole.
12.Close the drain and open the cold water supply and hot water outlet. If the relief valve was used for a vent ensure that it is now closed. Open the closest hot water valve to allow the air in the tank to vent as water enters the vessel. Close the valve opened for a vent when water flows from the valve.
13.Check the manway or hand hole and all related piping for any water leaks.
14.Turn on electric power to the circulating pump and other electric components if necessary.
15.Open valves for boiler water or steam supply. Also open the boiler water return, or condensate line.
16.Observe tank and piping to ensure all components are functioning properly.
Figure 7_Horizontal Storage Tank w/Anodes
Magnesium anode rod inspection
Glass lined storage tanks have a magnesium anode(s) to provide cathodical protection of the lining and minimize corrosion. Aggressive water conditions in some areas of the country may accelerate the deterioration of the anode(s). The anode(s) should be periodically removed and inspected to determine if replacement is necessary.
The tank must be valved off from the system and fully drained to remove an anode for inspection. Anodes are supplied in threaded fittings on the top head of small vertical storage tanks. Top mounted anodes may be accessed by removing the jacket top. Large vertical storage tanks and horizontal storage tanks have multiple anodes installed in threaded tappings along the length of the tank. These anodes may be accessed by removing a jacket panel and/or corner post corresponding to the mounting point of the anodes. Adequate service clearance is required to allow removal of an anode. The anode(s) should be replaced when more than six inches of the core wire is exposed at either end of the rod. Medium sized tanks with round jackets provide an opening for individual anode rod access.
Figure 8_Vertical Storage Tank w/Anodes
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