Flexible Joint Length.........

[TengkuSyahdilan]

Heloo...
I am in the middle of designing piping system for Oil Distribution and Pipeline System. We are using Flexible joint/Flexible tube at line that connect to Tank to avoid settlement and other movement cause by expansion or contraction, and also at line at Suction pump and dicharge line we also use same Flexible joint only different in length.My question is there any criteria or formula to calculate the right Length for Flexible joint so it can accomodate settlement or movement of pipe? am i correct if i make the length of flexible joint more short at suction and discharge line than at line that connect to tank?
Line inlet to tank 6",LineOutlet 6" with close drain 4", line at pump room 6". There will be Relief Valve of 2"x3" at Line inlet and outlet connct to tank and at line suction and discharge at pump room. Operation Pressure from Jetty to Tank 100Psi, from Tank toPump 50Psi and Temperature abient 25 C and Temperature Operation 45 C. i'm planning to use Flexible Joint ALL STS 304 with length 500 mm at line 6"inlet to tank and outlet from tank, 250 mm for pipe 4" line Outlet-Close Drain,butvi'mstill not sure to use the same length for pipe 6" at line suction and discharge pump?
Please give and advise about any criteria or formula for determining length of flexible joint.......

Best Regards

Tengku Syahdilan

 

[pennpiper]

I deduce from your description that you are NOT a trained and experienced piping designer. If you were you would be able to design this simple piping system without Flexible Joints.
Flexible joints are the weakest link in any piping system and should be avoided when ever possible.
I strongly recommend that you find a strong Piping Design Consultant to look at your project.

 

[IFRs]

I find it common to use expansion joints at the tank to accomodate tank settlement, especially when the pipe support is close to the tank. The selection of expansion joint length in these locations is based on the expected settlement over time and the expansion joint manufacturer's data sheet that shows length vs deflection. For other locations where piping routes or other constraints require even the most experienced piping designer to specify an expansion joint, the same method applies - determine the maximum lifetime motion and use the manufacturer's data sheet to select an expansion joint. Please don't forget to review the need for joint rods to limit axial expansion of the joint.

 

[TengkuSyahdilan]

Thanks for valuable input. I know that Flexible Joint is the last choise when designing Piping/pipeline system, we can use the right support at the right location to absorb thermal expansion or settlement. So why i use flexible joint here?? it is a request from our client, where i have explain in my presentation that if we can use the right support in the right place, with flexible routing of line we can avoid to use flexible joint. My client agree with me but it has been their standard in every system that they have to use Flexible joint at their Tank Distribution and Pipeline System.
So agin Thankfor any kind of input here.

Regards

Tengku Syahdilan