Boiler Manual - Weil-McLain

GV90+ gas-fired water boiler — Boiler ManualMultiple boiler water piping (continued)Figure 35 Piping layout — typical for multiple GV90+ boilers, using isolation exchangerUse isolation heatexchanger for:1. Large volume systems with highmineral content in water.2. Systems exposed to untreatedquantities of makeup water.3. Old systems severely contaminatedwith scale and rust buildupinside piping and heat distributionunits.4. Process applications.5. Commercial service water applications.6. High water pressure applications,requiring pressure relief settingin heating system more than 50PSIG (tall buildings). See notesbelow.Legend — Figure 351 Flow/check valve (each boiler)2 Isolation valves (when used)3 Cap4 Easy-Fit® Manifold (supply) —layout and size per page 245 Easy-Fit® Manifold (return) — layoutand size per page 246a Heating system circulator (exchangertube-side)6b Heat exchanger shell-side circulator7 Expansion tanks (diaphragm type)8 System air eliminator9 System automatic air vent13 Cold water supply connections16 Cold water fill line — see Figure32, page 25 for typical components18 Heating system supply19 Heating system return20 Boiler relief valve and dischargepiping, installed per GV90+ BoilerManual30 Sensor for BCP (boiler controlpanel), when usedNotes:1. Contact heat exchanger manufacturer for heat exchangershell-side and tube-side piping and circulatorrequirements. Tube-side flow and temperatures mustmeet heating system requirements.2. Contact heat exchanger manufacturer for sizing heatexchanger.3. Heat exchanger shell-side circuit requires its ownexpansion tank as shown.4. Heating system circuit requires its own expansion tank,as shown, plus its own relief valve set to protect heatingsystem and heat exchanger piping and components.5. When individual isolation valves are used, individualboiler and level controls may be required.28Part number 550-142-054/1211