Calculation Report for Branch Connection Reinforcement
Based on ASME B31.3, para. 304.3
AMTools-Piping, Copyright 2010 by Angelo M. Tolentino
Calculation Date: 4/4/2023
Input Data:
Pipe Outside Diameters, Dh = 36 inch, Db = 4.5 inch
Nominal Pipe Wall Thickness, tnh = 0.375 inch, tnb = 0.237 inch
Design Pressure, P = 185 psi
Stress Allowables, Sh = 20000 psi, Sb = 20000 psi
Quality Factor, Eh = 1, Eb = 1
Weld Reduction Factor, Wh = 1, Wb = 1
Coefficient, Yh = 0.4, Yb = 0.4
Allowances, Ch = 0.063 inch, Cb = 0.063 inch
Manufacturer Tolerance, Mh = 0.125, Mb = 0.125
Branch Angle (minimum 45 deg.) = 90 deg.
Fillet weld leg size at branch, w1 = 0.25 inch
Results:
1.0 Required pipe thickness
Pressure design thickness of header, th = 0.1659 inch
Pressure design thickness of branch, tb = 0.0207 inch
2.0 Calculation of Variables
Header pipe thickness, measured or min. per purchase specs., Th = 0.3281 inch
Branch pipe thickness, measured or min. per purchase specs., Tb = 0.2074 inch
Height of reinforcement zone outside of run pipe w/o repad, L4 = 0.3609 inch
Effective length removed from pipe at branch, d1 = 4.2113 inch
Half-width of reinforcement zone, d2 = 4.2113 inch
Min. weld throat requirement, tc = 0.1659 inch
Min. weld leg requirement at branch, w2 = 0.2346 inch
3.0 Reinforcement area calculations
Reinforcement area required, A1 = 0.6986 inch
Reinforcement area available in header pipe wall, A2 = 0.4179 inch
Reinforcement area available in branch pipe wall, A3= 0.0893 inch
Reinforcement area due to welds and other reinforcement, A4 = 0.0625 inch
Available area for reinforcement = 0.5697 inch
4.0 Reinforcement pad design calculations
Minimum thickness of reinforcing pad, tr = 0.375 inch
Reinforcing pad design width, wr = 1.1250 inch
Height of reinforcement zone outside of run pipe with repad = 0.6628 inch
Reinforcing pad minimum length, along header axis = 4.8438 inch
Minimum weld leg requirement at repad, w3 = 0.2652 inch
Minimum reinforcing pad height, rh = 0.3750 inch
Minimum reinforcing pad width, rw = 0.1719 inch
Maximum reinforcing pad width, max. rw = 1.9613 inch
Area reinforcement added by reinforcing pad, A5 = 0.8438 inch
Available area of reinforcement including repad = 1.4134 inch
**ACCEPTABLE. Reinforcing pad design is within limits.