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Technical specifications for Reduction Retort bottom section

SCOPEProcurement of raw materials & welding consumables, fabrication, inspection, testing and supply at

Central Stores, NFC, Hyderabad for NZSP. The following items as per the technical specificationmentioned herein & as per the drawings:

S.No. Item Code. Description Drawing Nos. Qty(Nos.)

1 210044948 Bottom section for C-NZSP-DWS-948 R1 10Reduction Retort

1.0 General:

If ordered quantity is split, the bidders shall be prepared to accept order .Minimum order Quantityshall be clearly mentioned by the parties in their offer.

All the materials of construction shall be procured from the manufacturers/ authorized agents of manufacturers. Local traders shall be avoided The material shall be neatly stacked by the vendorwith proper identification marks to avoid mix-up and to ensure correct usage. Inspection will becarried out at various stages by NFC QA as per agreed QA plan and will authorize for furtherclearance to the vendor.

The vendor shall give the details of Sub-contractor in case of any sub-contract and the sub-contractor shall be approved by the purchaser before sub-contracting.

Final approved drawings with / without minor revisions will be given to the vendor onplacement of order.

The vendor shall strictly comply with the approved drawings , specifications and codes andshall maintain and submit complete documentation of fabrication, inspection and testing atevery stage up to the final product.

2. 0 Applicable standards and codes:

a) ASME Boiler and pressure vessel code Sec VIII Div I, for fabrication, inspection and testingof the equipment.

b) ASME Boiler and pressure vessel code Sec V for inspection & testing standards andprocedures (UT, RT, PT, MPT & VT).

c) ASME Boiler and pressure vessel code Sec IX for welder and welding procedurequalification.

d) ASME Boiler and pressure vessel code Sec II for specifications and testing of materials of construction.

e) ASTM A 262 for IGC testing.f) ASME Sec. V SA 578 for ultrasonic testing of plates.

3.0 Materials of construction.

3.1 The stainless steel plates shall conform to SA-240 & SA-480 of ASME section-II Part A & shall

be in solution annealed and pickled condition. Other requirements such as the restriction onminimum carbon of 0.04%, Grain size, requirement of IGC test as per ASTM A 262-practice-E,

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Ultrasonic testing as per ASME – SA 578-Level-B etc shall be as specified in the respectivedrawings.

The plates shall be free from surface defects like pits, cracks, laminations and inclusions. If any grinding is done to remove these defects, it shall be ensured that there is a smoothmerger of the ground surface with the remaining surface and thickness is within the tolerance

limits of ASME SA 480.

3.2 All the welding consumables used for welding shall conform to 5.9 of ASME Sec II and shall beof standard make like Advani, L&T, D&H, Rajratna, ESAB any other brand as approved by thepurchaser.

3.3 ER 310 welding consumables shall be used for welding AISI 310S to AISI 310S.

4.0 Pre-Fabrication requirements:

4.1 The vendor shall submit a detailed manufacturing procedure, any additional workingdrawings, QC plan & stage wise check lists, NDT procedures and documentation formatsalong with time schedules to the purchaser for approval before fabrication.

Manufacturing plan shall include the detailed procedure of manufacture, the equipmentused and the tolerances that are maintained at various stages of manufacture to achieve the

final required dimensions. The alignment/ovality/skewness/flatness/finish shall be checked if givenin the drawing

4.2 QA plan shall detail the procedures for carrying out inspection and testing at various stagesof manufacture.

4.3 Templates, metrology instruments and testing consumables used in DP test, radiography etc.shall be approved by the purchaser.

4.3 The welder and welding procedure shall be qualified as per ASME Sec IX. However, if valid documents of welder and welding procedure qualification carried out earlier as per

ASME Sec. IX by QA, NFC or any other agency acceptable to the QA, NFC are availablewith the vendor, clearance for welding will be given on the basis of these documents.Otherwise welder and welding procedure qualification shall be carried out in the presenceof NFC QA and shall be approved by NFC QA. Production welding shall be taken up only

after clearance from NFC QA.

5.0 Fabrication:

5.1 The edges/surfaces to be welded shall be cleaned thoroughly using acetone/TCE beforewelding. After completion of welding, the inside weld reinforcement of all the welds shallbe ground flush with the parent material if specified in the drawing.

5.2 Machining to be carried out as given in the drawing.

5.3 The components after fabrication shall be free from injurious defects such as dents, Pits,handling marks, remains of fixtures etc.

5.4 The fabricated components shall be numbered as per the identification number given by thepurchaser and the number shall be written legibly by welding at the specified locations.

Repairs: If the number of repairs on an any weld during entire fabrication is more than three,the welder and welding procedure shall be re-qualified. The vendor shall not carry out anyweld repairs without the prior approval of the repair procedure from the purchaser.

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5.5 If dish end is made by welding two plates the butt weld shall be subjected to 100%radiography. The maximum allowable thinning on the dish end as measured with ultrasonicthickness gauge is 2 mm. OD of the dished end shall be maintained within the generaltolerance limits of IS-2102 (extra coarse) as checked with a go gauge. The knuckle andstraight flange of the dished end shall be free from unacceptable surface defects as detectedby DP test. Before final forming, the dished end shall be stress relieved by soaking at 900 deg

C for one hour followed by forced air cooling. If a hole is made in the dished end for thepurpose of forming, the same shall be closed by defect free weld as checked by 100%radiography. The weld design for closing the hole shall be approved by the purchaser beforewelding.

6.0 Inspection & Testing:

6.1 Inspection & documentation by the vendor shall be as per the approved QA plan.

6.2 Valid test certificates shall be submitted by the vendor for the material of construction.Inspection of materials of construction includes visual examination, dimensional inspection,chemical analysis and mechanical tests on the samples taken as per relevant specificationand drawing. 100% Visual inspection shall be carried out. One sample per heat and thicknessof SS plate shall be subjected to chemical, mechanical testing as per the ASME Sec. II & IGCPractice ‘E’ test as per ASTM A262 requirements and any other tests as given in therespective drawings.

All the tests shall be carried out at NABL accredited labs only.

6.3 Test certificates pertaining to the chemical compositions /mechanical properties for thewelding consumables shall be submitted by the vendor. One sample specimen of weldingconsumables / weld deposit from each heat, nominal diameter and batch shall be tested forchemical composition/ mechanical properties as specified in SFA 5.9 of ASME Sec. II C.

6.4 100% DP test shall be carried out on all the welds. D.P. testing shall be carried after edgepreparation, weld root pass, weld back gouged surface & on final welds. DP test shall becarried out by colour contrast penetrant technique using solvent removable penetrant

systems. Any unacceptable defect shall be corrected as per the procedure approved by theNFC QA followed by retest to ensure that the defects are within acceptable limits. The dye,developer and cleaner used for DP test shall be of reputed brands like Megnaflux, P Met (orany other brand approved by the purchaser) and spray type only and shall confirm to the

specifications given in ASME Sec. V. The acceptance criteria for defects shall be as per ASMESEC VIII requirements.

6.5 100% radiography shall be carried out after final pass for all the butt welds expect flanges asspecified in the respective drawings and any unacceptable defects shall be corrected as perthe procedure approved by the purchaser followed by re-radiography to ensure that thedefects are within acceptable limits. Radiography shall be carried out with X-rays only forreduction retorts. As per ASME Section V and the procedure given in annexure –II theconvention for carrying out the radiography is given in Annexure-III . The welds areacceptable only when the corresponding radiographs are acceptable as per the acceptancestandard of ASME section VIII division I. Radiography shall be carried out only after grindingthe inside weld reinforcement flush with the parent material if specified in the drawing.

Following shall be the hold points for stage wise inspection.

i) Pre-fabrication:

a) Raw material clearanceb) Consumable clearancec) Approval of manufacturing procedure, Manufacturing Engineering Instructions and QA plans.d) Welders and welding procedure qualification

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ii) In process clearance:

a) Shells inspection.b) Fit –up at all assembly stages.c) Flange clearanced) Dish inspection including heat treatment

e) Radiography of all butt weldsf) DPT of all weldsg) Final assemblyh) Final inspection

iii) Documentation:

a) Pre-fabricationb) In processc) Post fabrication

Note: The above are indicative. The actual hold points shall be as per the QA plan submitted by the Vendors and approved by the purchaser.

ANNEXURE – II TO TECHNICAL SPECIFICATIONS:

I Parameters used for carrying out X-ray radiography (for reduction retorts)

(a) X-Ray film to be used : AGFA D4/D7, IRF 150 or equivalent(b) Film to focus distance : 30” (750 mm)(c) Lead intensifying screens: Front 0.002” (0.05mm) : Back 0.006” (0,15mm)

(d) Penetrameter: ASTM strip type as per ASME SEC V (source side) – Essentialhole to be seen 2T

(e) Each shot length shall be adjusted to achieve the desired density

requirements (1.8 to 3)

III Lead markers shall identifyRetort No.

Date of testingSection details ( a,b,c _______) before starting the job.

IV The setup shall be certified by the approved QA agency Radiographs of onelongitudinal and one circumferential weld shall be certified by the approved QA agency before proceeding with the remaining job.

V All the radiographs shall be submitted to the purchaser along with evaluation reportsand shall remains as the property of the purchaser.

VI The developed films which do not conform to acceptable quality standards shall bediscarded and the welds re-exposed to achieve proper quality.

VII Radiography procedure shall be submitted by the vendor and this shall be approvedby the NFC.

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Annexure III to Technical Specifications Convention for lead marking

The following convention shall be followed while carrying out radiography on allreduction retorts which would facilitate easy identification whenever required.

The lead marker shall indicate the items (Reduction retort ) retort No., weld(circumferential / longitudinal). Section details (AB, BC, etc ) & date of testing.

1 Circumferential weld:The circumferential welds shall be numbered form the top end (open end) of theretort i.e CS1, CS2, _____etc. (see fig). The lead marking shall beRR/VDR______ Retort No._______Csi __________AB etcDate:Where i=1,2,3,4

“A” shall start from retort number marking on the bolted flange for reduction retortshall proceed in anticlockwise direction when viewed from flange sideExg:RR/VDR-8Q-CS1-AB

where RR =Reduction retort VDR=Vacuum Distillation Retort

8Q =Retort No,CS1=Circumferential weld 1

AB=Section AB

Date of testing … /……/20062 Longitudinal weld:

The numbering of longitudinal welds shall start from bolted flange of the retort andare numbered as LS1, LS2 etc. In order to number the welds within a shell, areference i.e retort number on bolted flange is taken for Reduction Retort. The firstlongitudinal weld shall be the one which will come first in anti clockwise directionfrom the retort number when viewed from the flange side (see fig)

The lead marking shall beRR/ VDR --Retorts No --- Lsi—AB etcDate:…../……/2006

Where i=1,2,3,4 “A” shall start from the flange side of the retortExg: RR/VDR-8Q-LS1-AB

Where RR=Reduction retort

VDR=Vacuum Distillation RetortBQ=Retort No,LS1-Longitudinal weld 1

AB=Section ABDate of testing…./…./2006

Refer to the enclosed sketch for detailsc

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