WELDED PIPES AND TUBES
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RAW MATERIAL FORM |
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Stainless
Steel in the form of Sheet and Coil as per ASTM – A 240 or relevant
specification. |
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STEEL MANUFACTURING PROCESS |
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The Electric
Furnace process of other primary process shall make the Steel. Separate
degassing or refining and may be followed by secondary melting, using
electroslag remelting. If so, the heat shall be defined as all of the ingots
remitted from a single primary heat. |
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IDENTIFICATION AND CERTIFICATION |
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Supplied
along-with test certificate given chemical composition, mechanical properties
as specified in by relevant specification. |
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SAMPLING |
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Materials are
inspected for identification correlating Mark/Tag with test Certificate. In
absence of t. C. or ambiguity in coleration, the sample is tested for
chemical and Hardness. |
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In case of
material purchased from dealer alongwith Test Certificate one sample per
coil/plate. |
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FOR SEAMLESS PIPES AND TUBES |
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RAW MATERIAL |
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Raw material
are stainless steel in the form of
Mother Pipes as per ASTM – A312 specification |
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IDENTIFICATION AND CERTIFICATION |
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Mother pipes
supplied alongwith test certificate giving chemical composition mechanical
properties, name of manufacturer, size of pipes, specification and H.T. No.
gets correlated on pipes with test certificates. |
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SAMPLING |
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Materials are
inspected for correlating marking on pipes with test certificates. In absence
of T. C. or ambiguity in co-relation, the samples are tested for chemical and
Hardness. |
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In case of
material purchased from dealer alongwith Test Certificate sample is tested
for chemical and hardness. |
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2 samples for
lot not more than 50 Pipes. |
QUALITY CONTROL PLAN
¼” OD – 5” OD
SPECIFICATION – ASTM A–249, A–269, A–312, A–213 &
OTHER INTERNATIONAL STANDARDS.
1/8” NB– 6” NB
QUALITY – TP – 304, 304L, 316, 316L, 310, 316 Ti, TP 317 ETC…
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Manufacturing Process |
Equipment |
Control Item |
Control Point and Specification |
Control Procedure |
Percentage of Inspection |
Identification Lot No. |
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SLITTING AND SHEARING (Not applicable for seamless pipes |
Slitting and Shearing Machine |
A: Strip Width B: Burr free out |
A) Tolerance as per Table QD – 2 B) Burr free out |
A) At the time of Setting |
A) Each Setting B) Each Cut |
Heat No., Size |
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FORMING AND WELDING (Not applicable for Seamless Pipes) |
5 Nos. Continuous pipe forming mill with automatic TIG
welding |
a) Welding Parameters b) Eld quality c) Forming quality |
A) Voltm7eter and Ammeter etc. B) As per ASTM &
other standard C) Forming Impression and size. |
a) At the time of setting b) Visual, reverse bends, flanging,
flattening and flaring. c) Visual and Micro Meter |
A. Each size, Each setting B. Sample testing C. Each tube & at the time of
setting |
Tube/Pipe Size, Quality, heat no….. Lot No. |
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Heat Treatment |
Oil Fired hearth continuos roller furnace with water, controls like Thermo Couples,
Pyrometers & Temperature Recorder |
A. Hardness B. Micro Structure (Supplementary |
Heating temperature Heating cycle & quenching as per
relevant specification and as per our establishment procedure |
A. Furnace Tempreture B. Hardness C. Micro test (Supplementary) |
Each |
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STRIGHTENING |
Straightening Machine |
Straightness & Dimension OD |
1 mm in any 100 mm Long |
Visual, Piano Wire |
100% Visual |
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POINTING |
Machine Pointing |
Pointing Length/Diameter |
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Diamension |
Initial Setting |
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DESCALING |
Poly propelene lined tanks. Solution HF and HN03 |
Surface Quality |
Composition of solution, dipping time |
Material surface check |
100% |
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LUBRICATION |
Rubber Lined Tank |
Adhesion of lubrication film |
A. Proper composition of solution B. Temperature dipping time |
A. Volumetric B. Check by Thermometer |
a. Titration every charge b. Random |
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A. COLD DRAWING or B. PILGERING |
Draw Bench Pilger Mill |
Diameter/Thickness, Surface quality, Diameter and
surface defects As per A-249, A-269, A-312, A– 213 |
A. dimensions of tools B. Wall Thick & Length |
A. Measuring B. Visua and Dimensional Check |
A. Each Tool B. Random Every change & Then random lot |
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DEGREASING AND DECOATING |
Lead lined tank |
A. Concentration of solution B. Temperature & dipping time |
A. Proper composition B. Thermometer measuring |
A. Titration B. Temperature check |
A. Every B. Few Hours |
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FINAL HEAT TREATMENT |
Oil fired continuous roller hearth furnace with water
quenching, Thermocouples and Pyrometers & Temperature |
A. Mechanical properties &
metallurgical uniformities B. Harness C. Micro Structure (Supplementary) |
Heating Temperature Heating cycle and quenching As per A-249, A-269 & A-312, A-213 etc… |
A. Atmospheric temperature, Heating
Cycle and quenching. B. Hardness C. Micro Test on Final Production (Supplementary) |
Each |
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FINAL STRAIGHTENING |
Sr. Machine |
Straightness Dimension OD |
1 mm in any 1000 mm Length |
Visual Inspection & threads |
Each Tubing Visual |
Same as above |
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FINAL CUTTING |
Cutting M/C |
Dimension |
Cut Length & Edge |
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Each Cutting |
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HYDRO DESCALING PICKLING & PASSIVATION |
Hydro Test Bench HF+HNO3 Bath 10% HNO3 6% HF |
Surface quality |
Pressure as per Specification Concentration desiccating solution |
Pressure Gauges & %
PPM Volumetric desiccating Solution % PE & Acid Contents |
Each Log 100% |
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FINAL INSPECTION |
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As per ASTM A-249, A-269, A-213, A-312 & Other relevant
specification Surface quality chemical composition. |
A. Dimensions OD and Thickness B. Surface Defects C. For ASTM –A 312 Seamless Weight
of Pipes/Tubes |
A .Measuring Micrometer & Vernier B. Visual Inspection C. Check Analysis laddle analysis
examination of Mill Certificate |
A. Each Tube & Pipes both ends. B. Each Tubing C. 1 Pc/Ht. |
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MARKING |
Electroetoning Machine |
Marking Machine |
Marking as per A530/A-450/A-700 1. Brand Mark 2. Name of 3. Grade specification 4. Dimensions 5. Heat Number |
Marking on each Tube |
Each |
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PACKING |
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Packing Condition |
Packing shall be ensured safe delivery of the Tubes in
good condition. Unit weight shall not exceed 1,500 Kgs. In gross & 1,000
Kgs. In nett as per A-700 (Purchase Order requirserment) |
Tubes/Pipes ends shall be protected with plastic Caps
& Shall be wrapped with gunny cloth or packed in wooden boxes as per
order specification upto 4"”NB Std.. Size pipe |
Each |
Each lot shall be identified by paint Marking |
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Marking on |
Marking as per A-700 1.
Purchasers Name 2.
Grade 3.
Tube size & Length 4.
No. of Tubes 5.
Box Serial No. 6.
Destination 7.
Country of Origin |
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Correlated
Mill Certificates, Which shall include as follows, will accompany material: -
1.
Chemical Composition (Laddlw/Check)
2.
Tension Test
3.
Flattening Test
4.
Flanging Test
5.
Hardness test
6.
Hydrostatic Test
7.
Dimensions