Raypak 503-2003 Installation And Operating Instructions Manual

Also see for 503-2003: Installation & operating instructions

Raypak 503-2003 Installation And Operating Instructions Manual Manual pdf 16 page image

SECTION C: Installation14Hydronic HeatingPump SelectionIn order to ensure proper performance of your heatersystem, you must install a correctly-sized pump. Ray-pak recommends designing for a ∆T within the rangeof 10°F to 40°F. See Table F for acceptable flow ratesfor each model (∆T is the temperature difference be-tween the inlet and outlet water when the heater isfiring at full rate).Feedwater RegulatorRaypak recommends that a feedwater regulator be in-stalled and set at 12 psi minimum pressure at thehighest point of the system. Install a check valve orback flow device upstream of the regulator, with amanual shut-off valve as required by local codes.PipingAll high points should be vented. A heater installedabove 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 inparallel 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 toheating coils located in air handling units where theymay be exposed to circulating refrigerated air, must beequipped with flow control valves or other automaticmeans to prevent gravity circulation of the heater waterduring the cooling cycle. It is highly recommended thatthe piping be insulated.Air-Separation/Expansion TankAll heaters should be equipped with a properly sizedexpansion tank and air separator fitting as shown inFig. 9.Fig. 9: Air-Separation/Expansion TankThree-Way ValvesThree-way valves intended to regulate system watertemperatures by reducing flow in the boiler should notbe used. Raypak heaters are high-recovery, low-massheaters which are not subject to thermal shock.Fig. 10: Single Heater - Low-Temperature (HeatPump) Application with Primary/Secondary PipingSee Fig. 14 and instructions on page 16 for adjustingthe manual bypass.Fig. 11: Dual Heaters (Reverse/Return)with Primary/Secondary PipingDomestic Hot WaterWhen designing the water piping system for domestichot water applications, water hardness should be con-sidered. Table G indicates the suggested flow rates forsoft, medium and hard water. Water hardness is ex-pressed in grains per gallon.