Week 11 Challenge
1)
AIM:
To detemine the friction load on the axis and friction force if there is TEFLON pad between shoe and pipe support.
Procedure :
Friction factor and friction load on piping:
| Materials | Friction Factor |
| Steel to Steel | 0.3 |
| Teflon to Steel | 0.1 |
(A) When Steel pipe is resting on steel:
Friction force in longitudinal direction = Coeff of friction x Gravity Load
= 0.3x125 KN = 37.5 KN
Friction load in transverse direction = 10% of piping operating load
= 0.1x 125 = 12.5 KN
(B) When Steel pipe is resting on Teflon :
Friction force in longitudinal direction = Coefficient of friction x Gravity Load
= 0.1x125 KN = 12.5 KN
Friction load in transverse direction = 10% of piping operating load
= 0.1x 125 = 12.5 KN
Result:
Friction load in longitudinal and Transverse directions are 37.5 KN & 12.5 KN respectively, when pipe is resting on steel and also friction forces are 12.5 KN & 12.5 KN respectively when pipe is resting on Teflon.
2)
Aim :
To identify the type of support such as Spring, Guyed, Stop or Semi Anchor ( Guyed+ Rest+ Stop) or Rigid Strut from the given images.
Theory:
Info on the given cases:
- Spring Support: Permit the pipe to move in vertical direction
- Rigid Support: Allow small angular displacement and thermal movement.
- Stop support: Restrains the movement of pipe in axial direction but allows the pipe movement in lateral direction
- Semi Anchor Support: Restrict the pipes to move in axial as well as transverse direction.
- Guyed support: Restrains the lateral movement in two direction therefore also limits the rotational movemement of pipe but permit axial movement of pipe
- Anchor Support: It does not permit the pipe to move in any direction thus movement in all 6 degrees of freedom is restricted.
Procedure:
For Fig.1:
-
Type of Support: Spring Support.
For Fig.2 :
-
Type of Support: Rigid Support.
For Fig.3 :
- Type of Support: Stop support.
For Fig.4:
- Type of Support: Semi Anchor Support.
For Fig.5:
-
Type of Support: Guyed Support.
For Fig.6:
- Type of Support: Anchor Support.
Result:
Types of Support has been identified for all the given cases.
3)
Aim:
To design a typical pipe rack bent in oil plant is to be prepared from the given data and figures.
Given:
Height of Column = 9 m
Height of First tier = 6 m
Height of Second tier = 7.5 m
Height of Third tier = 9 m
Width of Pipe Rack = 7.5 m ( C/C of Column in width of pipe rack)
Span of each Bay = 6 m
Number of bays = 7
Top tier of pipe rack has 3 no cable trays each 150 mm wide
Second tier of pipe rack has 4 pipes ,one of 24 " diameter and one of 12 " diameter, remaining two pipes are of 8" dia
First tier of pipe rack has 6 pipes ,one of 18 " diameter and remaining 5 pipes are of dia smaller than 8"
Elevation View:
PLAN VIEW:
Procedure:
- Open a new Staad file.
- Create the basic model of the above Pipe Rack in Staad File.
- Now we wil add the supports to the model.
- Now add the loadings on the Pipe Rack.
-
Add the following Load cases :
1- Structural Dead Load :
Load due to weight of Structure excluding weight of pipe i.e Self Weight.
2-Operating Dead Load :
- Weight of pipe, fluid in it and insulation.
- UDL of 1.9 kN/m2 is asuumed for pipe of dia 8".
- Point load is considered at appropriate location for pipes larger than 8" dia which will be reported by Piping Engineer.
3-Empty Dead Load :
- Weight of empty pipe without fluid in it but including insulation,it is assumed to be 60% of the operating load
4-Test Dead Load :
- In case test medium in pipe is not known, water with density of 1000 kg/m3 is considered as test medium .So in general test load is same as operating dead load.
5- Cable Tray Load:
- UDL of 1 kN/m is considered.
All of the above mentioned loads has been applied to the model.
-
Various Loads have been applied as shown below:
Structural Dead Load:
- Operating Pipe Load for 8" diameter pipe:
- Operating Pipe Load for 12" diameter pipe:
- Operating Pipe Load for 18" diameter pipe:
- Operating Pipe Load for 24" diameter pipe:
- Empty Pipe Load:
- Test Pipe Load:
- Cable Tray Load:
- Now, run the analysis to check the structure and make sure to check there are no errors.
- No error has been found during and after the analysis.
Result:
The Given Pipe rack structure has been modelled in the Staad Pro, with the given Dimensions, Loading, Supports and Specifications. Also the analysis of the Pipe rack model has been done successfully and no error has been found.