This document discusses slip-on flange welding according to ASME B31.3-2016 standards. It explains that slip-on flange welding uses an equal fillet weld and the weld size is measured by the leg length using a welding gauge. It provides equations for calculating the fillet weld size on both the flange face side and hub end side based on the pipe wall thickness and hub thickness. A practical example is given to demonstrate calculating the weld sizes for a sample stainless steel flange.

1. Slip on Flange
welding acc. to
asme b31.3-2016
Amr Soliman
met_3mr84@yahoo.com 1
INSPECTIONACADEMY

2. REF. : Fig. 328.5.2A Fillet Weld Size
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Slip on flange welding
is an equal FILLET
WELD type , as seen in
the Fig.
The related fillet weld
size is measured by
the LEG Length using
the welding gauge .
Amr Soliman

3. REF. : Fig. 328.5.2B Typical Details for Double-Welded Slip-On
and Socket Welding Flange Attachment Welds
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Via The below figure, we can calculate the LEG length from
both sides ( flange face side and flange hub size )

4. Amr Soliman
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Now, we have two different equations,
The Left side ( Flg. Face side ) : fillet weld size = The lesser of T or 6 mm.
The Right side ( Hub end side ) : fillet weld size = Xmin = the lesser of 1.4 T or the thickness of the hub .
HINT
: T= pipe wall thickness ( Ref. : ASME B36.10 for CS, or, ASME B36.19 for SS )
: Hub Thickness ( Ref : ASME B 16.5 for Flange size <= NPS 24 , ASME B16.47 for Flange size > NPS 24 )

5. Ref. : ASME B16.5
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The hub thickness =
(X-B) / 2
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6. Practical Example
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• Suppose that the St. st
Flange size is NPS 6,
Sch 40s, Class 150
_____________
• Question:
• What will be the fillet
weld size at both sides ?

7. Practical Example
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• Ans: Based on the dimension tables
of ASME B36.19, the wall thickness
( T ) will be 7.11 mm
_________________________
• Flg. Face side fillet weld size =
The lesser of T or 6 mm.
• So, the answer is 6 mm
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8. Ref. : ASME B16.5
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9. Practical Example
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• Using the previous table
• The hub thickness=
( 192-170.7)/2 = 10.65 mm
_________________________________
Hub end side fillet weld Size=
X min = the lesser of 1.4 T or the
thickness of the hub .
Xmin= The min. of 1.4x7.11 ( = 9.95 mm ) or 10.65
Hub end side fillet weld size = 9.95 mm

10. INSPECTION ACADEMY
Amr Soliman 10