2
Manufacturing• Flanges are
manufactured by forging• Large diameter flange are
made by ring rolling methods
• Final dimension are achieved by machining
3
Heat treatment • Normalizing• Solution annealing• Tempering• Quenching• Stress relieving• Combination of above
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.
5
Non Destructive testing• Ultrasonic test• Magnetic particle test• Liquid penetrant test• Positive Material Identification
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
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.
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#
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
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
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
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.
14
What you have learned?• Heat Treatment• Chemical & mechanical testing• Hydro Testing• Visual & Dimensional Inspection • Markings
15
See you in the next lecture…
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