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Flange Manufacturi

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Manufacturing• Flanges are

manufactured by forging• Large diameter flange are

made by ring rolling methods

• Final dimension are achieved by machining

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Heat treatment • Normalizing• Solution annealing• Tempering• Quenching• Stress relieving• Combination of above

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Hydrostatic Test• Not required unless

specifically requested by purchaser

• Code mandate that flange shall be able to withstand under pressure test of rating of finished part.

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Non Destructive testing• Ultrasonic test• Magnetic particle test• Liquid penetrant test• Positive Material Identification

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Distractive Testing• Tensile test• Hardness test• Impact test / Charpy V-Notch Test

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Metallurgical Test• Chemical Analysis of

−Raw material−Product

• Special test−Grain size (AS & SS)−IGC- Intergranular Corrosion Test(SS)−Ferrite (SS) −HIC- Hydrogen-induced Cracking−SSC- Sulfide Stress Corrosion Cracking

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Visual Inspection• Check for any surface imperfection and overall

product quality• Check for unfinished machine surface• Check for any serration damage on flange face • Being a machined product no surface defect is

acceptable.

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Dimension Standard• Dimension of flanged to confirm

−ASME B16.5- Pipe Flanges and Flanged Fittings NPS ½” to 24”

−ASME B16.47- Large Diameter Steel Flanges NPS 26” to 60”

• Flange are classified as per their pressure temperature ratings which are designated as 150#, 300#, 400#, 600#, 900#, 1500# and 2500#

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Dimension Standard• Weld neck and Lap joint flange also specified

schedule number to match with pipe thickness

• Weld nack Flange components −Flange body−Neck or hub−Raised face

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Dimension inspection • Following to be confirm during inspection

−Outer & Inner Diameter−Bolt Circle & Bolt hole Diameter −Hub Diameter & thickness of weld end−Length of the Hub−Straightness and alignment of bolt hole

• Permissible tolerances are given in B16.5 and B16.47 standard

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Marking • Following shall be marked on flange body

−Manufacturer logo−ASTM material code−Material Grade−Service rating (Pressure-temperature Class)−Size−Thickness (Schedule)−Heat No−Special marking QT (Quenched and tempered) or W

(Repair by welding)

VP 6” CL300 Sch80 A105 WNRF ABC12

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Marking• Marking can be done by painting or by Hard

punching• For stainless steel stenciling can be used• Flanged are marked in flange body thickness

area.

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What you have learned?• Heat Treatment• Chemical & mechanical testing• Hydro Testing• Visual & Dimensional Inspection • Markings

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See you in the next lecture…