Raypak 992B-1262B Pressure Drop in Feet of Head Feedwater Regulator, Piping, Three-Way Valves

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Pressure Drop in Feet of Head Feedwater Regulator

Raypak recommends that a feedwater regulator be in- stalled and set at 12 psi minimum pressure at the highest point of the system. Install a check valve or back flow device upstream of the regulator, with a manual shut-off valve as required by local codes.

Piping

All high points should be vented. Purge valves and a bypass valve should be installed. A heater installed above radiation level must be provided with a low wa- ter cut-off device (sales order option F-10). The heater, when used in connection with a refrigeration system, must be installed so that the chilled medium is piped in parallel with the heater with appropriate valves to pre- vent the chilled medium from entering the heater.

The piping system of a hot water heater connected to heating coils located in air handling units where they may be exposed to circulating refrigerated air, must be equipped with flow control valves or other automatic means to prevent gravity circulation of the heater water during the cooling cycle. It is highly recommend- ed that the piping be insulated.

Air-Separation/Expansion Tank

All heaters should be equipped with a properly sized expansion tank and air separator fitting as shown in Fig. 10.

heaters which are not subject to thermal shock. Raypak offers a full line of electronic sequencers that produce direct reset of heater water temperature.

(Refer to the Controls section of the Raypak Catalog.)

*

*Maximum 4 times the pipe diameter or 12”, whichever is less.

Fig. 11: Single Heater - Low-Temperature (Heat Pump)

Application with Primary/Secondary Piping

Fig. 10: Air-Separation/Expansion Tank

Three-Way Valves

Valves designed to blend water temperatures or reduce water circulation through the heater should not be used. Raypak heaters are high-recovery, low-mass

*

*Maximum 4 times the pipe diameter or 12”, whichever is less.

Fig. 12: Dual Heaters (Reverse/Return)

with Primary/Secondary Piping

Domestic Hot Water

When designing the water piping system for domestic hot water applications, water hardness should be con- sidered. Table H indicates the suggested flow rates for soft, medium and hard water. Water hardness is ex- pressed in grains per gallon.

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Contents Installation & Operating Instructions Page Contents Pay Attention to These Terms Installations at Elevation Before InstallationProduct Receipt Model IdentificationComponent Locations Back Component LocationsModel Quantity Vent Size Gas Burners Blowers General InformationValves Model Burners per Valve Stages Fire at StageWater Time to Produce Serious Temp Burn General SafetyTime/Temperature Relationships in Scalds Installation Codes InstallationEquipment Base StackingTable D Vent/Air Inlet Termination Clearances Clearances Indoor InstallationsOutdoor Installations Indoor Units Combustion and Ventilation AirReversing Air Filter Direct VentConventional Combustion Air Supply InstallationsTruSeal Combustion Air All Air from Inside the BuildingWater Piping Canadian InstallationsGeneral Reversing Water ConnectionsCold Water Operation Relief Valve Piping Hydrostatic TestPump Selection Temperature & Pressure GaugeHydronic Heating Piping Pressure Drop in Feet of Head Feedwater RegulatorAir-Separation/Expansion Tank Three-Way ValvesPool Heating Potable Water and Space HeatingWinterizing Your Heater Automatic Chlorinators and Chemical FeedersPool/Spa Water Chemistry Water Hardness Gas SupplyPH of Water Total Dissolved SolidsReversing Gas Supply Connection Gas Supply ConnectionModel Table I Maximum Equivalent Pipe LengthCheck the Power Source Electrical Power ConnectionsGas Supply Pressure Field-Connected ControllersMaking the Electrical Connections Field Wiring ConnectionOn-Off Wiring Connections Flue Exhaust Tee VentingModel Diameter Order Number Appliance CategoriesVent Terminal Location Support of Vent StackCombustion Exhaust Certified Combustion AirChanging the Flue Outlet InstallationsCanadian Installations Venting Configurations Venting Installation TipsInstallation Natural Draft Vertical Venting CategoryCommon Venting System TerminationCertified Vertical Venting Combustion Air Air Inlet Model HeightHorizontal Through-the-Wall Venting Category Horizontal Through-the-Wall Venting CategoryModel Certified Maximum Combustion Air Inlet Direct Vent Horizontal Through- the-WallVenting Equivalent Material Vent Length Intake PipeDirect Vent Vertical Direct Vent VerticalFreeze Protection Outdoor InstallationControls Models 992B-1262B Heater Sequence of OperationExternal Lights Color Indication Models 1532B 1802B Page Page Models 2002B 2342B Page Page Flow Switch High Limit Manual ResetIgnition Module Operating ControlLow Water Cut-Off Optional High and Low Gas Pressure SwitchesUDB Fault History UDB Diagnostic BoardVenting Appliance Categories 87%-Efficiency Boilers Special InstructionsWater Piping Condensate Management Vertical Venting CategoryVent Terminal Location Max. Length Material Vent Length Certified Maximum Combustion Air Air Inlet Model VentingEquivalent Direct Vent Horizontal Through- the-Wall 992BE 75’ 100’ 1262BE Galvanized Steel 1532BE Category 25’ Wiring Diagram Models 992B-1262B Wiring Diagram Models 1532B-2342B Pre Start-up START-UPStart-Up Blower AdjustmentMain Burner Adjustment Leak Test Procedure Dual-Seat Gas Valves Safety InspectionFollow-Up Pilot Turn-Down TestLeak Test Post Start-Up CheckTo Turn Off Gas To Appliance OperationLighting Instructions Step TroubleshootingPreventive Maintenance Schedule MaintenanceSuggested Minimum Maintenance Schedule Semi-Annually WeeklyAnnually As RequiredInside Air Contamination AppendixLimited Parts Warranty HI Delta Types H and WH Limited Parts Warranty HI Delta Type P START-UP Checklist for FAN-ASSISTED Raypak Products Page