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
http://www.syska.com/
AIR
Energy/images/StPOWER
Joes-Boiler-plnt.jpg
NATURAL GAS
MINOR UTILITIES
–
–
•
FIRE SYSTEMS
INERT GASES
WASTE DISPOSAL
–
–
•
SEWERS
HAZARDOUS MATERIAL
TREATMENT SYSTEMS
DISTRIBUTION &
TRANSPORTATION SYSTEMS
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–
–
ROADS
RAILS
DOCKS
http://www.smvrhm.org/2misc/un
k-boxcar-loading.jpg
ESTIMATE FACTORS
• DEPEND ON TYPE OF FACILITY
AUXILIARY PROCESSES CAN BE
COMPLICATED
• EXAMPLE OF WASTE TREATMENT
PROCESS
PIPING SYSTEM COST
ESTIMATES
•
•
ESTIMATES DEPEND ON
FOLLOWING FACTORS
TYPE OF SYSTEM
•
•
•
•
•
http://www.welcoser
WELDED
vices.com/pic3b.jpg
SCREWED
SWAGED FLANGES
WELDED FLANGES
MATERIALS OF CONSTRUCTION
– SEE TABLE 12-2 FOR ALTERNATE
TYPES
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
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/downlo
ad-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/go
od_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
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–
–
•
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.valvediagno
stics.com/media/pictur
s/gate.gif
http://www.offshore247.com/n
ews/article.asp?Id=3226
http://www.valvediagnostics.c
om/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/jackd
og/lockseam22.jpg
http://www.alibaba.com/cata
log/11115924/Quality_Pipe_
Fittings_Elbow_Bend_Tee_
Flange_Reducer.html
SPECIFIC EXAMPLE
Cl2 PLANTS
PRODUCTION ECONOMICS FOR DIAPHRAGM Cl2
Cl2 Capacity
Cl2 Production
ST/Y
ST/Y
275000
275000
450000
450000
Investment ($US millions)
Battery Limits
208
Off-Sites
100
Total Fixed Capital
308
1100000
1100000
330
158
487
662
317
978
PRODUCTION ECONOMICS FOR MEMBRANE Cl2
Cl2 Capacity
Cl2 Production
ST/Y
ST/Y
250000
250000
450000
450000
Investment ($US millions)
Battery Limits
221
Off-Sites
93
Total Fixed Capital
314
DATA FROM T. PAVONE
350
148
497
1100000
1100000
702
297
999