Example: stock market

Design Guide and Installation Details for ... - Heat Trace

Design Guide and Installation Details for Self-RegulatingHeating CableVisit Us At: Self-RegulatingHeating CablesDesign Guide and Installation Details for Self-RegulatingHeating CableThe RSCC 2700 self-regulating heat -ing cable is available with either atinned copper or stainlesssteel over-shield. Factory Mutual approved foruse in Class I, Division 2, Groups B,C, and D; Class II, Division 2, GroupG; Class III, Division 2 areas. It israted for T5 per NEC. Meets orexceeds requirements of IEEE ElectricalResistance heat TracingSpecifications. The RSCC 2300 self-regulating heating element is avail-able with either a tinned copper orstainless steel overshield. FactoryMutual approved for use in Class I,Division 2, Groups B, C, and D;Class II, Division 2, Group G; ClassIII, Division 2 areas. It is rated for T3per NEC and meets or exceedsrequirements of IEEE ElectricalResistance heat Tracing of Ground FaultProtective DevicesCaution.

Heat Tracing Pipe To determine the pitch and amount of RSCC self-regulating heating cable required to heat trace a pipe, you’ll need to know the pipe temperature to be maintained, minimum ambient tem-perature, pipe size and insulation type and thickness. Calculating Heat Loss 1. First determine temperature differ-ence (T) between temperature to

Tags:

  Guide, Design, Installation, Details, Heat, Trace, Heat trace, Design guide and installation details for

Information

Domain:

Source:

Link to this page:

Please notify us if you found a problem with this document:

Other abuse

Transcription of Design Guide and Installation Details for ... - Heat Trace

1 Design Guide and Installation Details for Self-RegulatingHeating CableVisit Us At: Self-RegulatingHeating CablesDesign Guide and Installation Details for Self-RegulatingHeating CableThe RSCC 2700 self-regulating heat -ing cable is available with either atinned copper or stainlesssteel over-shield. Factory Mutual approved foruse in Class I, Division 2, Groups B,C, and D; Class II, Division 2, GroupG; Class III, Division 2 areas. It israted for T5 per NEC. Meets orexceeds requirements of IEEE ElectricalResistance heat TracingSpecifications. The RSCC 2300 self-regulating heating element is avail-able with either a tinned copper orstainless steel overshield. FactoryMutual approved for use in Class I,Division 2, Groups B, C, and D;Class II, Division 2, Group G; ClassIII, Division 2 areas. It is rated for T3per NEC and meets or exceedsrequirements of IEEE ElectricalResistance heat Tracing of Ground FaultProtective DevicesCaution.

2 CODE 1996 STATES IN ARTICLE 427-22: Ground-fault protection of equipment shall be provided for each branch circuitssupplying electric heating equipment. Accesories1548-40 PTPE lectrical Connection Kit1548-40 PTJE lectrical Connection Kitwith Junction BoxSRHC-ESEnd Seal Kit1528-01019 Fiberglass Adhesive Tape .5" x 108'. 185 C1528-01017 Fiberglass Adhesive Tape .5" x 108'. 130 C1528-0A018 Aluminum " x 108', 2 mil thick1600-XXXXXT hermostats NEMA 4X and NEMA 7 Ambientand Line SensingConductorsSelf-regulatingconducti vecoreFluoropolymerjacketMetallicovershi eldOptionalfluoropolymerjacketConductors Self-regulatingconductivecoreThermoplast icelastomerjacketMetallicovershieldOptio nalfluoropolymeror thermoplasticelastomerouter jacketElectrical Specifications2703-1 2703-2 2705-1 2705-2 2708-1 2708-2 2710-1 2710-2 2305-1 2305-2 2310-1 2310-2 2315-1 2315-2 Service Voltage (Volts)120240120240120240120240120240120 240120240 Maximum Circuit Length (Feet)3306602705402104201803602404801802 80135200 Thermal Rating at 50-F (Watts/FT.)

3 33558810105510101515 Temperature RatingMaximum Maintain (Deg. F)15015015015015015015015025025025025025 0250 Maximum Exposure (Deg. F)18518518518518518518518536636636636636 6366 Factory Mutual approvals require the use of RSCC components and accessoriesConstruction of 2305/10/15 Construction of 2703/05/08/101 IntroductionDesign Guide and Installation Details for Self-RegulatingHeating CablePrinciple of OperationRSCC self-regulating heating cablesregulate their heat output in responseto changes in temperature. The highlyengineered conductive core increasesits heat output when the temperaturefalls and decreases its heat outputwhen the temperature help protect against impact andmechanical abuse, these heating cableshave a metallic overshield. Theseheating cables are Factory Mutualapproved for use in hazardous Design Guide was compiled tooffer a simplified systematic approachfor designing pipe heat tracing systemsutilizing the RSCC self-regulating heat -ing following step-by-step procedureswill enable you to determine the lengthof heating cable required to efficientlyheat Trace pipes, valves and VoltagesRSCC 240 VAC self-regulatingheatingcables can be operated at alternativevoltages.

4 The chart below comparesheating cable power output with prod-uct Adjustment FactorPart No. 208 Volts 277 Volts2703-2 .75 .86 .91 .93 .78 .86 .92 :Thermal output of 2705-2 5 50 F, powered at 208 VAC = 5 Watts/Ft. x .86 = 1 Heater Power OutputK Factor @ 50 F MeanInsulating MaterialTemperature (BTU/HR-FT2- F/Ft.)Glass (Expanded Silicate).040 Table 1 Thermal Conductivity (Ki) of Typical PipeInsulating Materials2 Visit Us At: heat Tracing PipeTo determine the pitch and amount ofRSCC self-regulating heating cablerequired to heat Trace a pipe, you llneed to know the pipe temperature tobe maintained, minimum ambient tem-perature, pipe size and insulation typeand heat Loss1.

5 First determine temperature differ-ence ( T) between temperature tobe maintained (Tm) and minimumambient temperature (Ta). T = Tm- Select insulation K factor from Table 1 (Ki) and divide by .021 todetermine conductivity ratio (Rk). Rk= Ki . Determine heat loss from Table 2A(Qa) by selecting pipe size andinsulation thickness. If piping isindoors multiply (Qa) by Calculate heat loss from pipe (Qp)by multiplying T by Rkand Qa. Qp= T x Rkx Heater Power OutputFrom Graph I (page 3) select the heaterwith the power output (Qh) which meetsor exceeds the heat loss (Qp) from the pipe. For non-metal pipe multiplythe power output Qhfrom the chart before selecting the some circumstances it may be desiredto use a heater with less power outputper foot of heater than the calculatedheat loss per foot of pipe.

6 In thesecases, the heater can be spiralledonto the pipe to achieve the requiredpower output per foot of pipe. Adeveloped power ration and heaterpitch will need to be DevelopedPower RatioTo calculate developed power ratio(Rp) divide heat loss from pipe (Qp) by heater power output (Qh). Rp= Qp Heater PitchTo determine the required pitch (P),select value from Tables 3A and 3B forcalculated value of (Rp) and pipe RequiredHeater LengthTo determine required heater length(Lh), multiply length of pipe (Lp) by (Rp).Lh= Lpx Thickness(IPS)(Inches)1/2"1"1-1/2"2"2-1/ 2"3"4"1 3 1-1 2-1 3-1 2A heat Loss (Qa) from Insulated Pipe (Watts/Foot- F).Values given above are heat loss for metal pipe in units of Watts/Foot of pipe per F temperature difference from pipe toambient temperature fiberglass Us At: Design Guide and Installation Details for Self-RegulatingHeating CableExample: (2700 Heater)Ta= -20 FTm= 40 FInsulation Calcium SilicatePipe Material MetalInsulation Thickness 2"Length of Pipe 100'Step I T= Tm-Ta= 40 - (-20)= 60 Step IIRk= K.

7 021= .031 .021= IIIQ afrom Table 2A for 6 IPSpipe and 2" thick insulationis . IVQp= T x Rkx Qa= 60 x x . VFrom Graph 1, at 40 F the 2708heater produces Qiof watts per foot. Select the 2708 heater for this Heater by SpirallingAssume that for the above exampleyou wish to use a 2705 Qi, from Graph 1, at40 F for the 2705 heater watt per VIRp= Qp Qh= VII The pitch, P, in inches fromTable 3A for 6 IPS and Rp= is 14 inchesStep VIIILh= Lpx Rp= 100' x 146' cable length Loss/Developed Power Ratio(IPS)(Inches) 3 Loss/Developed Power Ratio(IPS)(Inches) 3A Pitch in Inches of Heater Wrap on Pipe for GivenHeat Loss/Developed Power Ratios of 3B Pitch in Inches of Heater Wrap on Pipe for GivenHeat Loss/Developed Power Ratios of Loss/Developed Power Ratios should be rounded to the next highest Loss/Developed Power Ratios less than , run the heating cable parallel to the Us At.

8 heat Tracing ValvesTo determine the amount of RSCC self-regulating heating cable required toheat Trace a valve, you ll need toknow the pipe temperature to be main-tained, minimum ambient temperature, valve size and insulationtype and heat Loss1. First determine temperature difference( T) between temperature to be main-tained (Tm) and minimum ambienttemperature (Ta). T = Tm- Select insulation K factor from Table 1 (Ki) and divide by .021 todetermine conductivity ratio (Rk). Rk= Ki . Determine heat loss from Table 2B(Qb) by selecting valve size andinsulation thickness. If valve isindoors multiply (Qb) by Calculate heat loss from pipe (Qv)by multiplying T by Rkand Qb. Qv= T x Rkx Heater Power OutputFrom Graph I determine heater poweroutput for pipe temperature to be main-tained (Qh). If valve is non-metal multiplyvalue of Qhfrom graph by DevelopedPower RatioTo calculate developed power ratio(Rp) divide heat loss from valve (Qv) by heater power output (Qh).

9 Rp= Qv RequiredHeater LengthTo determine required heater length(Lh), multiply number of valves (Nv) by(Rp). Lh= Nvx Rp. Example: (2708 Heater)Ta= -20 FTm= 40 FInsulation Calcium SilicateValve Size 6 IPSI nsulation Thickness 2"Number of Valves 2 Step I T= Tm-Ta= 40 - (-20)= 60 Step IIRk= K .021= .031 .021= IIIQ afrom Table 2B for 6" valve and 2" thick insulationis . IVQv= T x Rkx Qb= 60 x x . VQhfrom Graph 1 for 40 F required temperature is VIRp=Qv Qh= feet per heater valveStep VIILh= Nvx Rp= 2 'ValveSizeInsulation Thickness(Inches)1/2"1"1-1/2"2"3"4"1 2B heat Loss (Qb) from Insulated Valves (Watts/ F)Visit Us At: heat Tracing FlangesDesign Guide and Installation Details for Self-RegulatingHeating CableTo determine the amount of RSCC self-regu-lating heating cable required to heat Trace aninsulated pipe flange, fitting or hanger, sim-ply find the size on the verticle axis, readacross to the appropriate device, then readdown to the horizontal axis to determine theamount of cable required per 10 F tempera-ture difference.

10 Multiply the temperature dif-ference by this value and divide by ten toget the inches of cable to use per sizing is determined by the width ofthe hanger. Example: for 60 F temperature difference:(2) 10" flanges (4" heater per 10 degreesdifference); 2 x 4 x 60/10 = "(1) 10" fitting (4" heater per 10 degrees difference); 1 x 4 x 60/10 = "(4) 7" wide hangers (4" heater per 10 degreesdifference); 4 x 4 x 60/10 = 96"Total 168"Total Allowance Required = 'Pipe flanges, fittings and hangers act asheat sink devices in a heat Trace must be made for these devices to maintain a consistent and opera-tional pipe flanges and fittings under two inches in size use four inches of heater perdevice. For hangers under two inches in size use six inches of heater per Allowances for Insulated Pipe Flanges, Fittings and Hangers6 Visit Us At: Positioning and Attachmentof Heating ElementDesign Guide and Installation Details for Self-RegulatingHeating CableSpiral Installationof Heating ElementNote:1.


Related search queries