Contractor shall supply and install the following:
Boiler Economizer model ______________ with the following performance ability:
- ____________ BTUs/HR Recovery
- ____________ #s/HR of Flue Gas Flow
- ____________ % in WC of Gas Side Pressure Drop
- ____________ Fuel Type (Natural Gas, #2 Oil, #6 Oil, Other - Please specify)
The economizer shall be a completely packaged _____________ steel tube, gas to water heat recovery device designed to meet A.S.M.E. Code requirements. Each unit shall be National Board registered. The economizer is to be of a rectangular design, and shall not require any gas bypass. Circular or coiled units are not acceptable.
The enclosure shall be of steel frame construction inserted with fully insulated, removable side wall panels, consisting of stainless steel interior sheet and painted steel exterior. Rear door panels shall be removable to permit unrestricted access to entire tube bundle to permit removal of individual tube elements. The finned tubes and finned return bends are to be exposed to the bulk of the flue gas flow. The tubes shall exit the enclosure through gas seal assemblies. The tubes shall be manifolded into the headers by means of coupling fittings. Tube replacement shall not involve any torching or welding.
The heat exchanger core shall consist of individual and fully removable ____________ steel tubes with ____________ steel fins at _____ fins per inch. Method of fin attachment shall be by a controlled atmospheric, high temperature, 99.9% metallurgical braze process. Welded, zinc binded, or AL-FUSED fin to tube attachment of any kind is not acceptable. The pressure vessel within the flue gas stream shall not contain any joint or welds to connections. The unit shall be provided with an A.S.M.E. Code safety relief valve.
Both inlet and outlet transitions are to be included. The lower transition is to be fitted with a series of baffles, drains, and dams to collect and divert flue gas condensate from entering the boiler. The entire stack opening shall be protected, not only sections. Any unit without provisions for keeping stack condensate out of the boiler shall not be considered. An offset stack is not acceptable. A letter of certification must be submitted with shop drawings stating that all water will be removed through the economizer drain system and will not run back into the boiler thus causing boiler damage.
Means of support for the unit shall be by either hanger rod or by rigid frame to floor.
