Heater Catalog - Watlow

Circulation HeatersWATROD and FIREBARCirculation HeatersOptions (Continued)Pressure VesselsAll catalog pressure vessel (tank) materials consist ofstandard schedule and 150# class forged fittings and aremade from one of the following materials:• Carbon steel• 316 stainless steelAll catalog pressure vessels (tanks) are steel unlessotherwise noted.316 stainless steel pressure vessels (tanks) arepassivated on all wetted surfaces. Available fromAssembly Stock on 2 1 /2 inch NPT and 4 or 6 inch ANSIflange circulation heaters.Passivated FinishFor critical applications, passivation will remove free ironfrom all wetted surfaces.Contact your Watlow representative for details.GasketsRubber, asbestos-free and spiral wound gaskets areavailable for all heater flange, and inlet and outletflange sizes.Watlow recommends ordering spares in case replacementbecomes necessary.To order, specify gasket type, flange size/rating andprocess operating temperature.For details on gasket materials and temperature ratings,see page 240.Inlet and Outlet Nozzle ConnectionsAll inlet and outlet materials are compatible with thepressure vessel material and pressure class rating.Vessel sizes from 1 1 /4 to 8 inches are typicallyconfigured with MNPT (Male National Pipe Thread)nozzles. Optional NPT and flange sizes can be suppliedto mate with existing piping.10 inch and larger vessels are supplied with Class 150inlet and outlet flanges. Optional Class 300 or Class 600can be provided to mate with existing piping.To order, specify type, size and pressure class ratingfor both inlet and outlet nozzle/flange connections.Protective Steel Jacket (Shroud)To protect circulation heaters from weather orwash-down conditions, partially welded (standard) outerprotective steel jackets are available. Standard steel, ormade-to-order 304 or 316 stainless steel or aluminumcan be supplied. Jacket diameter is dependent uponthermal insulation thickness.To order, specify protective steel jacket, material typeand weatherproof, if desired.334 WATLOW ®