Hi All
This is me first post in this forum.
We have 250NB size of Fire Fighting Pipe line.
The Material of Pipe is GI and we have used Flexible Victaulic Couplings for the complete system. Now we have to do supporting of this system.
Can anyone help me what factors one needs to consider while doing supporting of this system.
This is urgent as we have problem at site in supports!!!

Hi Vupul,

Please find attached Caesar model for Victaulic couplings , some related information.

Regards,

kumar

Support span for the victaulic couplings.

Hi
Thanks for the reply
Does one needs to consider the effect of expansion in pipe due increase in pipe pressure (in this case it is around 20bar). How to take care of this?

pressure due to extension for the couplings to be considered.
pressure makes very important role in victaulic couplings.
If u have any quires please let me know

Hi

I have to go to site to rectify the support system. Support design has been done considering the rigid couplings and now there is leakage of water during hydrotest.
The pipe is running in rectangular path inside the building (50mx30m)
My solution and understanding so far is like this -
1. I will provide rest+guide at both the ends of all the couplings to rigidify the system.
2. After providing this kind of supports if pipe expands due to pressure then the solution which i considered was to provide anchor at every change of direction but then the load coming is very high (120KN) and this pipe is GI so I cannot do any welding on pipe and now I am stuck what to do??

- Vipul

the Victaulic Couplings (VCs) are not as strong as the pipe.
Have you checked that the bending moments on the VC's are within the allowable ?

Send me the Caesar Model.

kumar

We are not doing any calculation for this system as the system is cold (Design Temp - 30°C / Op Temp - 20°C).
Does Caesar calculate axial movement due to pressure thrust for this type of coupling.
How to model this coupling in Caesar?
If the pipe is erected with the maximum gap the coupling allows then will there be any axial movement??

- Vipul

Please refer my attachment ( WORD FILE ) and caesar model.

In felxible victaulic couplings max gap only : 3.2mm
Style 77S

Do we need to do calculation for this system (despite being cold)??

Dear Sir/Friends,

It is really interesting to learn about Vic. Coupling and its real world application. I read your post and view the Victaulic coupling model, it is nice. I have couple of doubts, kindly clarify me.

1. In the word file that you have attached, the 4th point, you stated to locate an anchor (assumed a straight line pipe) at one end and in other end to allow the Vic. Couplings move freely. Do I understand it correct? If yes, the anchor loads at the one end would be more which requires huge foundation, instead the anchor is shifted to center then both sides Vic. Couplings are provided to reduce the thermal expansion which may reduce the anchor load as well as in foundation size and thermal expansion too.

a. Please correct me if my understanding is wrong?

b. For an ‘L’ shaped line which is the best place to locate the anchor and Vic. Coup. say one end is free and other end is connected to a main line inside the plant.

2. Kindly explain me the 5th point in detail. The attached page 048 is missing it is to calculate the yield moment. Also I don’t get the point how Vic. Coupling becomes flexible if the applied bending moment exceeds a certain value.

3. I have calculated the pressure thrust force, in CAESAR II how to apply this. I applied the pressure thrust force as shown in fig. 3 page 18 June, 1998. Is it correct? Also for STYLE 77 from 06.04 Vic. Catalogue page No. 1 states that the coupling is offered for pressures up to 1000 psi. Is this pressure limit for circumferential direction? But inside the table the Max. Work Pressure limit is low compared to this value.

4. Finally, torsion moment, how to calculate this? I observed in CAESAR II model you had given stiffness (RZ-Pipe axis) torsion moment. Page 047 is missing from your word file.

Thanks in advance.