IBC VFC 15-150 Installation And Operating Instructions Manual

Also see for VFC 15-150: Manual Operating instructions manual

IBC VFC 15-150 Installation And Operating Instructions Manual Manual pdf 26 page image

INSTALLATION AND OPERATION INSTRUCTIONS1-20VFC 15-150, VFC 45-225 MODULATING GAS BOILERSWATER PIPING1.6.1 General Piping IssuesThe VFC modulating series boilers are designed for use within a closed loop,forced circulation, low pressure system. A 30 psi pressure relief valve (3/4" NPT)is supplied for field installation in the flow supply line – see below. An optional 75Psig relief valve can be used where required on closed loop systems within multi-level buildings. Relief valve discharge piping must terminate between 6" (15cm)and 12” (30cm) above the floor using plain un-threaded end, or per local Code.System piping is connected to the boiler using the 1-1/4" NPT-M threaded fittings.Unions and gate or ball valves at the boilers supply and return water connectionsare recommended to simplify servicing. Un-insulated hot water pipes must beinstalled with a minimum 1/4" clearance from combustible materials.Fluid fill is most often accomplished by using a boiler regulator & fill valve setat 12 psig or more, with appropriate backflow prevention device as required bylocal code. This is acceptable in areas where municipal water or well water hasbeen treated and filtered to remove excessive minerals and sediment, and waterchemistry is known to be suitable for closed loop hydronic systems. In areas wherewater quality is in question, or when chemical treatment or glycol is required, otheroptions should be considered. Follow applicable Codes and good piping practice.There are a number of boiler feed and pressurization devices on the markettoday that may be a better choice than a raw water fill from the mains. Whenregular maintenance requires relief valve blow-off, the discharge may be directedback into the pressurization unit for recycling of boiler fluid and chemicalsback into the system. In buildings that may be unoccupied for long periods oftime, pressurization units are useful to prevent flood damage should leakageoccur from any component in the system. An additional benefit is that backflowprevention devices are not required when using these devices.Figure 23: Boiler trim optionsCAUTIONInstallers should inquire oflocal water purveyors as tothe suitability of their supplyfor use in hydronic heatingsystems.If water quality isquestionable, a local watertreatment expert mustbe consulted for testing,assessment and, if required,treatment.Alternatively, water orhydronic fluid of knownquality can be brought to thesite.WARNINGDuring operation, the reliefvalve may discharge largeamounts of steam and/or hotwater. Therefore, to reducethe potential for bodilyinjury and property damage,a discharge line MUST beinstalled that it:1. is connected from the valve outletwith no intervening valve anddirected downward to a safe point ofdischarge.2. allows complete drainage of both thevalve and the discharge line.3. is independently supported andsecurely anchored so as to avoidapplied stress on the valve.4. is as short and straight as possible5. terminates freely to atmospherewhere any discharge will be clearlyvisible and is at no risk of freezing.6. terminates with a plain end which isnot threaded.7. is constructed of a material suitablefor exposure to temperatures of375°F or greater.8. is, over its entire length, of a pipe sizeequal to or greater than that of thevalve outlet.DO NOT CAP, PLUG OR OTHERWISEOBSTRUCT THE DISCHARGE PIPEOUTLET!1.6