Reinforcement of Welded Branch Connection

One of the first methods of providing branch connections was to stub a branch line into a run. Sometimes a pad would also be used to reinforce the connections. The figure below shows a header with pad-reinforced branch connections. Although tees and extrusions have generally taken the place of reinforced branch connections, an example calculation is presented for the occasional instance where the designer may want to use this type of connection.
PTLB Facilities – Liquid – 2.4_Intro.png

Nomenclature:
Refer to figure for a physical representation of the applicable terms.
𝐴𝑅 = (𝑡𝑟𝐷𝑜), Required reinforcement area
𝐴𝑝 = 𝐴1 + 𝐴2 + 𝐴3, Required reinforcement area of
𝐴1 = 𝐷𝑜(𝑇𝑟 − 𝑡𝑟), The area lying within the reinforcement zone resulting from any excess thickness available in the run wall.
𝐴2 = 2𝐿(𝑇𝑏 − 𝑡𝑏), The area lying within the reinforcement zone resulting from any excess thickness available in the branch pipe.
𝐴3 = 𝑡𝑝(𝑑𝑝 − 𝑑), The area lying within the reinforcement zone resulting from the addition of a pad of branch reinforcement member.
𝑑 = Outside diameter of branch pipe(in)
𝑑𝑐 = Corroded internal diameter of branch pipe(in)
𝑑𝑝 = Outside diameter of the reinforcement pad(in)
𝐷 = Outside diameter of run(in)
𝐷𝑐 = Corroded internal diameter of run(in)
𝐷𝑜 = Corroded internal diameter of extruded outlet measured at the level of outside surface of run(in)
𝐸 = Longitudinal Joint Factor
𝐹 = Design Factor
𝑇 = Temperature derating factor
𝐿 = Height of the reinforcement zone.
L is the lesser of: (1). 2.5 𝑇𝑏 + 𝑡𝑝 or (2). 2.5𝑇𝑟
𝑃 = Design pressure of the branch connection
𝑆 = Yield strength of the component being considered(i.e. run, branch, pad)
𝑡𝑏 = The required thickness of the branch pipe according to the steel pipe design formula, PTLB Facilities – Liquid – 2.4_Intro_3.png but not including any thickness for corrosion.
𝑇𝑏 = Actual thickness od the run wall, not including corrosion allowance(in)
𝑡𝑟 = The required thickness of run according to the steel pipe design formula, PTLB Facilities – Liquid – 2.4_Intro_2.png , but not including any thickness for corrosion.
𝑇𝑟 = Actual thickness of the run wall, not including corrosion allowance
𝑡𝑝 = The required thickness of the reinforcing pad

Input Parameters
To create a new case, click the “Add Case” button
Select the Reinforcement application from the Pipeline Facilities section.
Enter Case Name, Location, Date and any necessary notes.
Fill out all required fields.
Make sure the values you are inputting are in the correct units.
Click the CALCULATE button.
Design Properties
Design Factor F
Temperature Deration Factor T
Operating Pressure
F- Design Factor
T – Temperature Derating Factor
Header Properties
M – Thickness of the added reinforcement
D – Outside Diameter of the Header
H- Nominal Wall thickness of the Header
Specified Minimum Yield Strength
E- Longitudinal Joint Factor
Branch Properties
Db – Outside Diameter of the Branch
B – Nominal Wall thickness of the Branch
Specified Minimum Yield Strength
E- Longitudinal Joint Factor

Minimum Reinforcement Outside Data
Reinforcement SMYS
Distance through the Electrolyte Traveled by the Current(cm)
Cross Sectional Area through which the Current Flows (sq. cm)
PTLB Facilities – Liquid – 2.4_Input.png

PTLB Facilities – Liquid – 2.4_Input_2.png

PTLB Facilities – Liquid – 2.4_Input_3.png

Outputs/Reports
View the results.
If an input parameter needs to be edited be sure to hit the CALCULATE button after the change.
To SAVE, fill out all required case details then click the SAVE button.
To rename an existing file, click the SAVE As button. Provide all case info then click SAVE.
To generate a REPORT, click the REPORT button.
The user may export the Case/Report by clicking the Export to Excel/PowerPoint icon.
To delete a case, click the DELETE icon near the top of the widget.
t – Required Wall Thickness of the Header
(H – t) – Excess Thickness in the Header Wall
tb – Required Wall Thickness of the Branch
(B – tb) – Excess Thickness in the Branch Wall
AR – Reinforcement Required
A1 – Reinforcement Provided
L – Height
A2 – Effective Area in Branch/Outlet
A2 – Corrected Effective Area
A3 – REQUIRED AREA
AP – PROVIDED AREA
PTLB Facilities – Liquid – 2.4_Output.png

Related Links
Pipeline Facilities – Liquid Services