Learn about Manufacturing Methods, Heat Treatment, Destructive & Non-Destructive testing and Standard Marking requirements for flange used in process piping.

1. Flange
Manufacturing
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2. 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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3. Heat treatment
• Normalizing
• Solution annealing
• Tempering
• Quenching
• Stress relieving
• Combination of above
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4. 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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5. Non Destructive testing
• Ultrasonic test
• Magnetic particle test
• Liquid penetrant test
• Positive Material Identification
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6. Distractive Testing
• Tensile test
• Hardness test
• Impact test / Charpy V-Notch Test
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7. 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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8. 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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9. 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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10. 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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11. 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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12. 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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13. 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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14. What you have learned?
• Heat Treatment
• Chemical & mechanical testing
• Hydro Testing
• Visual & Dimensional Inspection
• Markings
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15. See you
in the next lecture…
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