View
246
Download
10
Category
Preview:
Citation preview
ADVANTAGES & ACTUAL LIMITS TO USE OF TMCP PLATESFOR LARGE STORAGE TANKSCONSTRUCTION
CMP DUNKERQUE PRESENTATION:
HEAVY FABRICATION PLANT IN NORTH OF FRANCE
ERECTED IN 1967 FOR FABRICATION OF HEAVY PRESSURE VESSELS FOR REFINERIES:CARBON & CHROMIUM MOLYBDENIUM STEELS UP TO 250 MM THICK
IN 1981 BOUGHT BY CBI FOR PREFABRICATION OF LARGE STORAGE TANKS & SPHERES:HLE STEELS & LOW TEMPERATURE CARBON STEELS
IN 1995 BOUGHT BY ENTREPOSE FOR PREFABRICATION OF CRYOGENIC TANKS & LARGE CRUDE OIL TANKS:9% NICKEL STEEL & HLE STEELS
ERECTION OF LARGE STORAGE TANKS
10 000 M3 SPHERES
125 000 M3 CRUDE OIL FRT
Beijing Natural Gas Project
ContractCFRFC-P98201
ENTREPOSE
DUNKERQUE
10 Spheres of 10 000 m3
Nanhuqu Site 4 spheres
Xiaotun Site 4 spheres
Beijiao Site 2 sphere
December 1998 - April 2001
Spheres Plates at Xingang Port
Spheres Plates stored at Nanhuqu Site
Internal scaffolding at Xiaotun Site
Erection of columns - Xiaotun Site
Erection of equatorial plates in progress - Xiaotun Site
Erection of equatorial plates completed - Xiaotun Site
Spheres before welding, erection completed - Xiaotun site
Four spheres under construction - Xiaotun site
Four spheres under construction
Nanhuqu site
Single Deck floating roof
Double Deck floating roof
...BACKWARD HOME...FORWARD...
Erection of plates•The first step of construction is the erection, welding and NDT of bottom annular plates.
The erection of bottom plates and shell plates starts.
FORWARD......BACKWARD HOME...
Plates storage at site
•A suitable area is required in the near vicinity of the construction for storage of plates and other material.
•The plates are stored using wood wedges in order to guaranty the curvature.
FORWARD... HOME...
Plates Assembling•The square nuts are welded on the plates.•The plates are assembled with the key plates and the conical pins as shown here-under.
FORWARD......BACKWARD HOME...
Diameter and roundness control•Square nuts and conical pins are used to adjust the diameter of the first ring.
FORWARD......BACKWARD HOME...
Fabrication & installation of outer scaffolding
• The wind girder is used as scaffolding. Handrails are installed.
In order to provide free access to the workers, whatever is the design width of the girder, the actual width is at least 1m.
FORWARD......BACKWARD HOME...
Welding Technique• The vertical welds are welded from individual
cradles, by manual welding (coated electrodes). These cradles provide wind & rain protection for the
• welders.
FORWARD......BACKWARD HOME...
Welding Technique•The circular welds are welded simultaneously on both sides with an automatic welding machine (Arc Submerged•Welding). The machine turns automatically around the tank and carries two operators connected by radio, one on each side of the plate.
FORWARD......BACKWARD HOME...
Welding machine & cradle displacement
•When a vertical weld is completed the cradle rolls on the plate until the next weld.
• When a ring of plates is completed
the welding machine and cradles are
lifted on the above ring of
plates.FORWARD......BACKWARD HOME...
Tank Erection• Free access around the tank is required for
cranes and lifting operations.
FORWARD......BACKWARD HOME...
5 X 125 000 M3 FRT IN EQUADORERECTION IN PROGRESS
4 x 50 000 m3 DDFRT in GEORGIA
Erection completed!
...BACKWARD HOME...
AT THIS STAGE I HOPE YOU UNDERSTAND HOWSITE CONDITIONS ARE DIFFERENT FROM LABORATORY!
WE AS CONSTRUCTION PEOPLES HAVE TO FACE ONSITE VERY BAD WEATHER CONDITIONS:
WATER FLOODING
WIND STORM
DEEP FREEZING
WE HAVE ALSO TO USE VERY LOW HEAT IMPUTWELDING PROCESS FOR ERECTION PURPOSE
AT THE END WE HAVE TO GUARANTEE CRACK FREEHUGE EQUIPMENTS WITH HOMOGENEOUS MECHANICALPROPERTIES THROUGH THICKNESS
CONSTRUCTION CODES& TMCP STEELS:
SPHERES
LARGE TANKS
PRESSURE VESSEL CODES AUTHORIZE USE OF TMCP STEELS WITHOUT LIMITATION FOR SPHERES
THEY REFER TO EN 10028 PART 5 OR EQUIVALENT
EN 10028 PART 5 DEFINE 3 GRADE OF STEELS:P355 / P420 / P460
FOR EACH GRADE THERE ARE 3 LEVELS OF TOUGHNESS = 27 JOULES AT T/4:
M FOR -20°C / ML1 FOR -40°C / ML2 FOR -50°C
MAXIMUM CEQ VALUES:T< 16MM P355 < 0.39 P420 < 0.43 P460 < 0.45T< 40MM P355 < 0.39 P420 < 0.45 P460 < 0.46T< 63MM P355 < 0.40 P420 < 0.46 P460 < 0.47
API 650 AUTHORIZE USE OF TMCP STEEL FOR LARGESTORAGE TANK
THE MAXIMUM GRADE AUTHORIZED IS 355
MAXIMUM THICKNESS AUTHORIZED 40 MM INSTEADOF 45MM FOR NORMALISED 355 GRADE
MAXIMUM GRADE AUTHORIZED IN Q&T STEEL 420
MAXIMUM THICKNESS IN Q&T STEEL 45 MM
NEVERTHELESS API 650 AUTHORIZE PURCHASER TO SPECIFY HIGHER VALUES UNDER HIS RESPONSABILITY
PROPERTIES OF TMCP VERSUS NORMALISED
FOR THE SAME GRADE TMCP HAS LOWER CHEMICALCONTENT ; FOR A 355 GRADE STEEL 40 MM THICK
TYPICAL ANALYSIS ARE AS FOLLOW:
CARBON : TMCP 0.10 / NORMALISED 0.14MANGANESE : TMCP 1.30 / NORMALISED 1.60NIOBIUM : TMCP 0.02 / NORMALISED 0.03CEQ : TMCP 0.37 / NORMALISED 0.42
DUE TO CONTROLLED ROLLING PROCESS THECHEMICAL ANALYSIS OF TMCP IS MUCH MOREHOMOGENEOUS THAN NORMALISED AND LEADTO DIMINUTION OF CARBON SEGREGATION AND
FURTHERMORE TO BETTER TOUGHNESS PROPERTIESMAINLY MID THICKNESS
WELDABILITY OF TMCP VERSUS NORMAISED
AS ALREADY FORESEEN CHEMICAL ANALYSISOF TMCP FOR THE SAME GRADE IS FAR LOWER THAN NORMALISED STEEL
IT MEANS PROBLEMS ON SITE ARE LESS WITH TMCP THAN WITH NORMALISED STEELS
IT MEANS ALSO WE CAN USE HIGHER GRADESOF TMCP I.E 420 WITH THE SAME WELDABILTYTHAN 355 NORMALISED GRADE AND INCREASETHE MAXIMUM SIZE OF LARGE STORAGE TANK
CONCLUSION
MAJOR STEEL MAKERS ARE TODAY USED TO PRODUCETMCP PLATES 50 MM THICK AND OVER ON A DAILY BASIS
CODES AUTHORISE USE OF THESE TMCP FOR LARGE SPHERES & STORAGE TANKS
WE HAVE TO CONVICE END USERS TO USE GRADE 420& OVER TO BE ABLE TO INCREASE MAXIMUM SIZESOF THESE LARGE TANKS IN A BETTER TECHNICO ECONOMICAL WAY THAN USING Q&T STEELS
Recommended