Heater Catalog - Watlow

Reference DataWattage RequirementsKilowatt-Hours to Superheat Steam1. Plot points on lines P, Q and S. P represents the inlettemperature (and saturation pressure) of thesystem.Q represents the liquid content of the water vapor.S indicates the outlet temperature minus the saturatedtemperature.W indicates the heat content of the water vapor.2. Draw a straight line from P through Q to W. Read W 1 .3. Draw a straight line from P through S to W. Read W 2 .4. Required watts = Weight (lbs) of steam/hour x (W 2 -W 1 )Watt density is critical. Review temperature and velocityprior to heater selection.Example Shown:Q = 90% quality (% R.H.)P = 75 psigS = 320°FSuperheat SteamSaturated Temperature—°F450400350300250210P4003001501005025100Gauge Pressure—lbs/in 2Q859095100100200300400500600700800Quality—% R.h.Degrees of Superheat—°F9000102030405060708090100110120130140150160170180190SW200Heat Content—Watt–hour/lbNote: Reference is based on >80% steamquality at >20 psig.552WATLOW ®