137 STEAM TRACING DESIGN GUIDELINES - Control …

1 Fax: INTRODUCTIONS team TRACING is one of many ways topreheat, add heat and prevent heatloss from piping systems and theircomponents. Some other ways are: Jacketed piping Hot water and oil TRACING Dowtherm tracingJacketed piping systems are used pri-marily to maintain a constant high tem-perature. Due to its high cost of con-struction, jacketed systems are seldomused except where temperature controlis critical. Hot water and oil must bepumped at a high velocity to maintaina desired temperature, and must havea separate return header as does Dow-therm. Hot water, oil or dowtherm arealso an additional system which add tothe cost of a TRACING is most often selectedbecause: There is generally available a surplusof low and/or medium pressuresteam.

2 STEAM has a high latent heat andheat-transfer-coefficient. STEAM condenses at a constanttemperature. STEAM flows to end-point withoutthe aid of pumps (when designedcorrectly). A small amount of return piping isneeded due to existing USESF reeze Protection (winterizing) Adding sufficient heat to above-grade piping systems and equip-ment which are exposed to ambienttemperatures below the freezingpoint of their media prevents A Desired Temperature The viscosity of some liquidsbecomes higher as their tempera-tures become lower causing moredifficult and costly pumping andleading to down-time for cleaning. Condensation may occur in somegases if the ambient temperaturefalls below the dewpoint which isharmful and expensive in suchsystems as:-Natural Gas where Control valvesfreeze up and burners Suction Lines wherecompressors can be MATERIALS team TRACING material is normally asfollows:-Use the material specified for steampiping from the STEAM header (throughthe distribution manifold, if applicable)to and including the tracer block 1/4 through 7/8 copper orstainless steel tubing (depending on thedesign conditions) from the block valveto the STEAM trap.

3 Though sizes mayvary with different applications, 3/8 and 1/2 are the most often fittings and adapters are normallyflareless compression type or 37degree flared the material specified forcondensate piping from the STEAM trap(through the collection manifold, ifapplicable) to the condensate headeror end-point (drain or grade). DESIGN GUIDELINES1. STEAM piping should be run within12 of the line or equipment beingtraced to minimize exposed TRACING should be limited tovertical piping using multipletracers on horizontal lines whichrequire more should be designed sothat the flow is always pockets! ! Where verticalflow is unavoidable, steampressure should be a minimum of25 PSIG for every 10 of Tracers should be a maximum of100' long and continuous fromthe supply to the collectionmanifold or endpoint.

4 For linesover 100 long, provide anothertracer and overlap the two 3inches to avoid cold should have no branchtees except as indicated inSection Provide each tracer with aseparate strainer and STEAM can be horizontal orvertical depending upon thedesign Tracers should be attached to thepipe at 8 to 10 maximumintervals with stainless steel tension should be sufficientto hold the tracer secure andflush against the Some piping materials, such aslined pipe, might require spacerblocks to avoid hot spots .10. Tracer loops with unions arenecessary: when joining tubing lengths. at all break flanges andunions. at all flanged discharge lines should beas short as possible since longdischarge lines can freeze evenwith a fully functioning TRACING DESIGN GUIDELINES