RBI DOMINATOR Series Installation And Operation Manual

Also see for DOMINATOR DB-1050: Installation & operating instructions

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RBI DOMINATOR Series Installation And Operation Manual Manual pdf 15 page image

DOMINATOR INSTALLATION AND OPERATION INSTRUCTIONS Page 15Expansion Tank & Air SeparatorAn expansion tank or other means to control thermalexpansion must be installed in the heating system. Anexpansion tank must be installed close to the boiler onthe suction side of the pump. An air scoop and automaticair vent must also be installed to eliminate air trappedin the system.Primary/Secondary PipingBoilers connected to heating systems using zone valves,zone pumps, or systems that have excessive flow ratesor return water temperatures less than 125°F, 52°Cmust be isolated from these systems to protect the boiler.Variable Water FlowsFigure 11 shows a typical primary/secondary pipingsystem. A dedicated pump is used to maintain aconstant water fl ow through the boiler. This secondarypump is sized to overcome the head loss of the boilerand secondary piping system while supplying the fl owrate required to maintain the desired temperature riseacross the boiler. The primary pump is sized to providethe required fl ow to the heating system. The secondarypiping connections to the primary system piping mustnot be more than 12 in, 305 mm apart to ensure zeropressure drop in the primary system, see Figure 11.Low Return Water TemperaturesTo prevent the problems associated with condensationof the products of combustion due to low return watertemperatures a primary/secondary piping system witha bypass and bypass valve must be installed, see Figure12. The bypass and bypass valve must be sized thesame as the secondary piping. A balancing valve mustalso be installed in the supply side of the secondarypiping downstream of the bypass. The balancing valveshould be adjusted to diver t some of the heateddischarge water into the return water until the requiredinlet water temperature is achieved. The primary andsecondary pumps should be sized to provide therequired flow through each system. The secondarypiping connections to the primary system piping mustnot be more than 12 in, 305 mm apart to ensure zeropressure drop in the primary system, see Figure 12.Multiple Boiler SystemsSystems using multiple boilers can also be installedusing a primary/secondary manifold system, Figure 13.Piping For Use With Cooling UnitsThe boiler, when used in connection with a refrigerationsystem, must be installed so the chilled medium is pipedin parallel with the boiler. Appropriate valves must be usedto prevent the chilled water from entering the boiler.When a boiler is connected to a heating coil that maybe exposed to refrigerated air from an air handlingdevice, the piping system must be equipped with fl ow-control valves or some other automatic means ofpreventing gravity circulation of the boiler water duringthe cooling cycle.HEATING SYSTEM PIPINGGeneral Piping RequirementsAll heating system piping must be installed by a qualifiedtechnician in accordance with the latest revision of theANSI/ASME Boiler and Pressure Vessel Code, SectionIV, and, when required, ANSI/ASME CSD-1, Standardfor Controls and Safety Devices for Automatically FiredBoilers. All applicable local codes and ordinances mustalso be followed. A minimum clearance of 1 in, 25 mmmust be maintained between heating system pipes andall combustible construction. All heating system pipingmust be supported by suitable hangers not the boiler.The thermal expansion of the system must be consideredwhen suppor ting the system. A minimum systempressure of 12 psig, 82.7 kPa must be maintained.Heating Boiler Piping ConnectionsThe supply and return piping should be sized to suit thesystem. The supply and return connection sizes arelisted in Table 8.Table 8 - Supply & Return Connection SizesModel Size Supply Return300 thru 2100 2 1/2" NPT 2 1/2" NPTPump RequirementsThis low mass boiler requires a continuous minimumwater fl ow for proper operation. The system pump mustbe sized to overcome the head loss of the boiler and theheating system in order to achieve the requiredtemperature rise. Table 7 provides the heat exchangerpressure drop and temperature rise figures. Thetemperature rise across the boiler must never exceed35° F, 19.4° C.CAUTION: A temperature rise outside of the rangelisted in Table 7 indicates that the flow rate through theheat exchanger is incorrect which will damage theheat exchanger voiding the warranty! The maximumallowable temperature rise is 35°F, 19.4°C.The maximum allowable flow rate through aDominator boiler with copper heat exchanger is105 GPM, 6.6 L/s. The cupro-nickel heat exchangerallows for 120 GPM, 7.6 L/s.An adjustable pump delay is available as a feature ofthe staging controller. The pump delay establishes waterfl ow through the boiler and heating system before theappliance starts. Consult the staging controller manualfor further details.Low Water CutoffIf a boiler is installed above any radiation elements itmust be fitted with a low water cutoff device.Refer to wiring diagram supplied with the boiler/waterheater for proper wiring connections.