API Specification 2B• Specification for the Fabrication of Structural Steel Pipe . • Sixth Edition, July 2001:Effective from Jan.1 2002. • Scope: It covers the fabrication of structural steel pipe formed from steel plate with longitudinal and circumferential butt-welded seams suitable for use in offshore structures • Size 14” and large (40in. For LWDS) • Thickness 3/8in.(9.5mm) and greater • Max.length – 40ft(12.19m) Cylindrical tubular member fabricated from one or more lengths of structural pipe. used to join tubular sections into lengths of straight pipe Longitudinal seam – Butt welded seam which is parallel to the axis of the pipe. Pile . usually driven through a leg or sleeve of an offshore platform .API Specification 2B • • Definitions Can – A section of structural steel pipe with no girth weld Girth weld – Circumferential butt welded seam lying in a plane perpendicular to the longitudinal axis of the pipe. that carries vertical loads and resist lateral forces • • . .API Specification 2B Material • As specified by the purchaser. mill test certificate must be available and also mill identification numbers. Purchaser shall specify the grade and quality of plate steel • If the plate is supplied by the fabricator. and match the minimum ultimate strength of the base material and provide a minimum of 20ft-lbs Charpy V Notch impact energy at 00F .Structural welding code. Welding electrodes and fluxes shall confirm to AWS spec. SAW process shall be used for all welding unless otherwise approved by the purchaser – except tack welds.API Specification 2B • • • • • • Fabrication Normally Cold formed (below 4000F) Hot formed with approved procedures Purchaser shall specify the plate rolling direction if the plate is to be oriented in a specific direction.1.2000. root passes and repair welding. All welds shall be complete joint penetration welds in accordance with AWSD1. – For LWDS pipe. 25% of smaller seam spacing Girth welds – Radial offsets of abutting edges of girth seams shall not exceed 0.2T (Tsmall thickness) or 1/4in. no two girth welds shall be located closer than 10ft • .API Specification 2B • Fabrication contd… Longitudinal welds – Radial offsets of abutting edges of LWS shall not exceed 1/8in(3. – Longitudinal seams of adjoining cans shall be staggered as below – Single seam – 900 to 1800 LWDS (1800) – 450 TO 900 Other LWDS – min. provided the offset exceeding 1/8” is welded from both sides – No two girth welds shall be located closer than one pipe diameter or 3ft.2mm). – There shall be no more than two girth welds in any 10ft-interval of pipe. – For LWDS pipes. Max. whichever is less. no two longitudinal weld seams shall be closer than one pipe diameter or 5ft whichever is greater. • Circumference – Outside circumference shall be within +1% of the nominal circumference or within+1/2” whichever is less. Length and Wall thickness – Diameter.API Specification 2B Dimensions and Tolerances • Diameter. for wall thickness upto 2” – For wall thickness above 2“ out of roundness to wall thickness ratio shall not exceed 1:8 – For pipes exceeding 48” dia. . provided the circumference tolerance is maintained within +1/4”. Length and Wall thickness shall be as specified by the purchaser. max permitted is ½” . • Roundness – Out of roundness (difference betwn major and minor outside diameter at any point in length shall not exceed the following – 1% of OD or ¼” max. – The length of each pipe shall not vary more than +1 ½” per 10ft of length. it shall be 30 degrees with +2. • Straightness – Max. not to exceed 3/8” in any 40ft length.API Specification 2B Dimensions and Tolerances contd. • Pipe ends – Unless specified. allowable straightness deviation in any 10ft length – 1/8” – For above 10ft length -( 1/8” x total length in ft)/10ft ..5 degrees with root face of 1/6”+1/32”. – The length of each pipe shall not vary more than +1 ½” per 10ft of length. . .1. section 5. – Repair of defects deeper than 20% thickness or width more than 20% of nominal diameter shall not be repaired.1 Repair of Base Metal Imperfections – Imperfections detected in the base petal in the finished tube no deeper than 5% of the specified nominal thickness or 1/16” in depth need not be removed. Weld profile shall meet the requirements of AWSD1.100% of each girth weld & 10% of spot testing of each longitudinal weld(including the extreme ends) as per AWSD1. – Imperfections above this and less than 20% of nominal wall thickness may be repaired by welding. Imperfections above this shall be ground to sound metal.API Specification 2B • Inspection and Repair Inspection – Fabrication and Inspection as per AWSD1.1 • • • Weld Inspection – All welds shall be inspected on the inside and outside surfaces. – Thickness in the ground area shall not be reduced more than 7% of the nominal thickness or more than 1/8”.24 Nondestructive Examination – RT or UT . SR1. – Fabricator’s name – API Monogram shall be applied – API 2B – Plate material designation – Nominal Outside diameter – Nominal wall thickness – Specified supplementary requirements.SR2.SR3 or SR4 .API Specification 2B Marking • Inspection – Each section of the pipe shall be paint stenciled on the inside of both ends with letters of height 1” min with the following details. 1 Orientation of the pipe axis relative to the final rolling direction of the pate shall be longitudinal or Transverse as specified in the purchase order – Pipe fabricated as per this supplementary requirement shall be identified by marking S-1L or S-1T CVN Toughness Tests – Notch toughness tests shall be conducted as a requirement of the welding procedure qualification tests as per AWSD1.API Specification 2B Supplementary requirements • SR1 Plate Rolling Direction Orientation – SR1.1 – Pipe shall be identified 100 percent Radiographic Examination – 100% RT of the longitudinal seam shall be conducted • • • Matching weld CVN Toughness for Designated Plate Material – Charpy test shall be conducted for specimens from the weld metal and HAZ of a simulated Production weld coupons shall be tested .