PRESSURE DESIGN STRAIGHT PIPE ( RUN PIPE)

GENERAL

Where

minimum required thickness, including mechanical, corrosion, & erosion allowances, mm. 10.86t pressure design thickness for internal pressure, mm. 9.36c sum of the mechanical allowances (thread or groove depth) plus corrosion & erosion allowances, mm. 1.5

STRAIGHT PIPE THICKNESS UNDER INTERNAL PRESSURE

1. t=(PxD)/2(SxExW+PxY) 9.36 2. t=P(d+2c)/2[SxExW-P(1-Y)] 8.87

Where

P 4.2D Outside Diameter of Pipe, mm. 406.4

S 88.25E Quality Factor For Longitudinal Weld Joints in Pipes. 1W Weld Joint Strength Reduction Factor. 1Y Coefficient for Materials. 0.7d Inside Diameter of Pipe, mm. 364.40

REINFORCEMENT OF WELDED BRANCH CONNECTIONS

tm=t+c

tm

Internal Design Gauge Pressure, N/mm2.

Stress Value for Material, N/mm2.

h subscript referring to run or header.b subscript referring to branch.

nominal thickness of run or header. 21

nominal thickness of branch. 13

effective length removed from pipe at branch, mm. 199.35

"half width" of reinforcement zone, mm. 199.35

height of reinforcement zone outside of run pipe, mm. 42.19

branch pipe thickness, mm. 11.38

header pipe thickness, mm. 18.38

minimum thickness of reinforcing pad, mm. 18.4

pressure design thickness of run pipe, mm. 9.36

pressure design thickness of branch pipe, mm. 5.12β smaller angle between axis of branch and run. 90

outside diameter of branch pipe, mm. 219.10

outside diameter of run pipe, mm. 406.40

199.35

126.43

199.35

42.19

43.09

REQUIRED REINFORCEMENT AREA

1865.70

AVAILABLE AREA

Where

1498.33

401.51

-34.14

Outside diameter of reinforcement ring, mm. 406.4

88.25

Height of the fillet weld between run pipe & reinforcement ring, mm. 3.00

Height of the fillet weld between branch pipe & reinforcement ring, mm. 3.00

1498.33

401.51

1899.85

Additional reinforcement required NO

-34.14

3441.64

18.00

NOTES:

1. All values are rounded of upto two decimal places.2. Some nomenclatures which are not present in the figure have been added for carrying out calculations.3. Height and base of the fillet welds is assumed to be equal.

Th

Tb

d1

d2

L4

Tb

Th

Tr

th

tb

Db

Dh

1. d1 = [Db - 2(Tb - c)]/sin β

2. d2= greater of d1 or (Tb - c) + (Th - c) + d1/2

Therefore d2

3. L4 = lesser of 2.5(Th - c), mm or

2.5(Tb - c) + Tr, mm.

1. A1 = thd1(2 - sinβ), mm2

A2 + A3 + A4 >= A1

A2 Area resulting from excess thickness in the run pipe wall, mm2.

A3 Area resulting from excess thickness in the branch pipe wall, mm2.

A4 Area of other metal provided by welds & properly attached reinforcement, mm2.

Dr

Sr Stress value for reinforcement ring material, N/mm2.

ha

hb

1. A2 = (2d2 - d1)(Th - th -c)

2. A3 = 2L4(Tb - tb - c)/sinβ

3. A2 + A3

A1 - ( A2 + A3 ) <= A4

1. Area of reinforcement ring, mm2.

2. Area of fillet weld, mm2.

4. d2 in any case shall not be greater than Dh.

PRESSURE DESIGN STRAIGHT PIPE ( BRANCH PIPE)

GENERAL

Where

minimum required thickness, including mechanical, corrosion, & erosion allowances, mm. 6.62t pressure design thickness for internal pressure, mm. 5.12c sum of the mechanical allowances (thread or groove depth) plus corrosion & erosion allowances, mm. 1.5

STRAIGHT PIPE THICKNESS UNDER INTERNAL PRESSURE

1. t=(PxD)/2(SxExW+PxY) 5.12 2. t=P(d+2c)/2[SxExW-P(1-Y)] 4.80

Where

P 4.20D Outside Diameter of Pipe, mm. 219.1

S 88.25E Quality Factor For Longitudinal Weld Joints in Pipes. 1W Weld Joint Strength Reduction Factor. 1Y Coefficient for Materials. 0.4d Inside Diameter of Pipe, mm. 193.10

tm=t+c

tm

Internal Design Gauge Pressure, N/mm2.

Stress Value for Material, N/mm2.