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DIRECT FIXED COST ESTIMATES. ESTIMATE METHODS FOR AUXILIARIES AND SPECIFIC COMPONENTS. AUXILIARY FACTILITIES . AS LISTED IN THE TEXT:. GENERAL CATEGORIES. PLANT UTILITY SYSTEMS STEAM WATER AIR POWER NATURAL GAS MINOR UTILITIES FIRE SYSTEMS INERT GASES WASTE DISPOSAL SEWERS
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DIRECT FIXED COST ESTIMATES ESTIMATE METHODS FOR AUXILIARIES AND SPECIFIC COMPONENTS
AUXILIARY FACTILITIES • AS LISTED IN THE TEXT:
GENERAL CATEGORIES • PLANT UTILITY SYSTEMS • STEAM • WATER • AIR • POWER • NATURAL GAS • MINOR UTILITIES • FIRE SYSTEMS • INERT GASES • WASTE DISPOSAL • SEWERS • HAZARDOUS MATERIAL TREATMENT SYSTEMS • DISTRIBUTION & TRANSPORTATION SYSTEMS • ROADS • RAILS • DOCKS http://www.syska.com/Energy/images/St-Joes-Boiler-plnt.jpg http://www.smvrhm.org/2misc/unk-boxcar-loading.jpg
ESTIMATE FACTORS • DEPEND ON TYPE OF FACILITY
AUXILIARY PROCESSES CAN BE COMPLICATED • EXAMPLE OF WASTE TREATMENT PROCESS http://www.uscentrifuge.com/images/process-operation2-lg.jpg
PIPING SYSTEM COST ESTIMATES • ESTIMATES DEPEND ON FOLLOWING FACTORS • TYPE OF SYSTEM • WELDED • SCREWED • SWAGED FLANGES • WELDED FLANGES • MATERIALS OF CONSTRUCTION • SEE TABLE 12-2 FOR ALTERNATE TYPES http://www.welcoservices.com/pic3b.jpg
PIPING DESIGN CRITERIA • MAXIMUM VELOCITIES • DIAMETER IS GENERALLY SET TO MEET PROJECT CRITERIA • SEE TABLE 12.3 AND NOTE LIMITS AS A FUNCTION OF VISCOSITY • SPECIFIED PRESSURE DROP (SEE MEMO CTA-02) • USE SPECIFIC EQUATIONS FOR LAMINAR, TURBULENT, COMPRESSIBLE AND INCOMPRESSIBLE FLOW. • CHOOSE MORE CONSERVATIVE (LARGER DIAMETER) WHEN COMPARING RESULTS FROM VARIOUS MODELS • AVOID SONIC VELOCITY (VALVES ARE PRIMARY SOURCES)
OTHER CONSTRAINTS • CODES • ASME B31.3 – PROCESS PLANT PIPING • ASME B31.1 – STEAM PIPING http://www.fluidh.com/images/imgCalcPumpHead2.gif
SYSTEM CURVES • PRESSURE DROP IN FLUID FLOW LINES (TOTAL HEAD) • USING EQUIVALENT LENGTHS REQUIRE SOME IDEA OF THE ROUTING. • FACTORS IN CRANE OR CAMERON. www.fluidedesign.com/download-free/chapter4-extract.pdf
PIPING INSTALLATION OPTIONS • OVERHEAD PIPING SYSTEMS ARE EASIER TO MAINTAIN • RUN PIPING IN RACKS • MINIMUM SIZE IS GENERALLY 2"(NOM) TO ALLOW REASONABLE SPAN OF ABOUT 25 FT • RACK PIPING LAYOUT SHOULD ISOLATE INCOMPATIBALE MATERIALS • USE STRUCTURAL STEEL IN BUILDINGS http://www.sococo.co.uk/petro-chemical.htm
SUBSURFACE PIPING • GENERALY LOCATED IN TRENCHES • DOES NOT INTERFERE WITH MOST SURFACE OPTIONS • CAN LIMIT SPREAD OF LEAKS WHEN FLUIDS FLOW INTO TRENCHES • TRENCHES MUST BE PERIODICALLY DRAINED • HAVE MIXED EFFECTS IN FIRES • MANY PLANTS HAVE A COMBINATION OF OVERHEAD AND SUBSURFACE PIPING http://www.nasm.si.edu/udvarhazy/bts/good_place/hazy_4.jpg
DETAILED PIPING DESIGN FACTORS • ATTEMPT TO MAINTAIN CONSTANT VELOCITIES THROUGH SYSTEMS FOR PURPOSES OF EFFICIENCY • USE WELDED WHERE LEAKS OF HAZARDOUS MATERIALS WOULD BE POSSIBLE • FLANGED FITTINGS ARE USED WHERE LINES MIGHT BE FREQUENTLY OPENED FOR MAINTENANCE • LINES 2-3"(NOM) IN DIAMETER MAY BE RUN IN THE FIELD. LARGER SHOULD BE FABRICATED IN SHOP.
PIPING QUALITY CHECKS • RADIOGRAPHY REQUIREMENTS • RANGE FROM 0% ON LOW RISK SYSTEMS TO 100% ON HIGH RISK • 5% RANDOM A TYPICAL INTERMEDIATE VALUE. • THERMAL AND MECHANICAL STRESS CONSIDERATIONS • EXPANSION MUST BE CONSIDERED AND SYSTEMS DESIGNED TO HAVE ZERO STRESS ON EQUIPMENT NOZZLES • NPSH MAY BE A FACTOR WHEN DESIGN FOR PUMP INLETS. SEE PERRY'S FOR GUIDELINES • AVOID VAPOR TRAPS IN EQUIPMENT PIPING • CONTROL VALVES SHOULD BE ISOLATED TO ALLOW REMOVAL FOR MAINTENANCE WITHOUT SHUTTING DOWN THE SYSTEM
VALVE DESIGN CRITERIA • DEPEND ON MEDIA AND SERVICE • POSITIVE SHUTOFF - GATES, PLUG, BALL • GASES - GATES FOR SHUTOFF, BUTTERFLYS FOR THROTTLING • CHECK VALVES - PREVENT BACKFLOW AND SHOULD BE INSTALLED AFTER ROTATING EQUIPMENT http://www.valvediagnostics.com/media/pictures/gate.gif http://www.offshore247.com/news/article.asp?Id=3226 http://www.valvediagnostics.com/media/pictures/check.gif
RELATIVE COSTS FOR PIPING • SEE FIGURES 12-4 THROUGH 12-12 • PIPING COSTS ARE LOWEST FOR SCREWED PIPING, BUT THIS IS GENERALLY LIMITED TO 6” DIAMETER OR LESS • STRAIGHT RUN PIPE IS GENERALLY FIELD FABRICATED IN 20 FT SECTIONS • AUTOMATIC WELDING MACHINES FOR FIELD INSTALLATIONS ARE AVAILABLE FOR STRAIGHT RUNS • SCREWED CONNECTIONS CAN ALSO BE INSTALLED IN LONGER SECTIONS
OTHER PIPING COST FACTORS • PIPE WITH BENDS, FITTINGS, VALVES, MULTIPLE CONNECTIONS IS TYPICALLY FABRICATED IN A SHOP • THE SHOP CAN BE LOCATED IN THE FIELD FOR PIPE UNDER 1 FT IN DIAMETER • LARGE PIPE FABRICATIONS ARE COMPLETE IN A SHOP WITH AUTOMATED WELDERS http://home.iprimus.com.au/jackdog/lockseam22.jpg http://www.alibaba.com/catalog/11115924/Quality_Pipe_Fittings_Elbow_Bend_Tee_Flange_Reducer.html
SPECIFIC EXAMPLE Cl2 PLANTS DATA FROM T. PAVONE