Raypak 302-902 Installation And Operating Instructions Manual

Raypak 302-902 Installation And Operating Instructions Manual Manual pdf 16 page image

SECTION F: DOMESTIC HOT WATER PIPINGWhen designing the water piping system for domestic water applications, water hardness should be considered. Table F-1indicates the suggested flow rates for soft, medium and hard water. Hardness is specified as grains per gallon.TABLE F-1DOMESTIC WATER HEATERFLOW RATE REQUIREMENTSDT = Temperature rise, degrees F DP = Pressure drop, ft, through heat exchanger SHL = System head loss, ft.GPM = Gallons/minute, flow rate MPS = Minimum pipe size, NPTSystem head loss based on heater and tank placed no more than 5 ft. apart and equivalent length pipe/fittings as follows:2î NPT = 75 ft.* Must use optional cupronickel tubes.POTABLE WATER AND SPACE HEATING APPLICATIONCAUTION: When this heater is used for both -potable water and space heating- follow the steps belowto insure proper operation.A. All piping materials and components connected to the water heater for the space heating applicationshall be suitable for use with potable water.B. Toxic chemicals, such as used for boiler treatment, shall not be introduced into the potable water usedfor space heating.C. If the water heater will be used to supply potable water, it shall not be connected to any heating systemor components previously used with a nonpotable water heating appliance.D. When the system requires water for space heating at temperatures higher than 140∞F, a means such as amixing valve shall be installed to temper the water in order to reduce scald hazard potential.SINGLE DOMESTIC HOT WATER HEATER WITH ONE STORAGE TANK16 Fig. #9224.1City Water System ReturnHot Water Supply