hi to all,
we have 3 pumps as shown below attachment, in this 3 pumps, 1 is always operating 2 are stand-by, worst case 2 are operating 1 standby. forces and displacements we don't know as we have not procured pumps yet.middle pump is stand-by.Suction header nozzle is connected to Newly fabricated Tank, Can any one help me how to consider tank settlement also.

now we what to write load case for worst case.

Can you please help me out with load cases.

Since the tank is very close to the pumps, if settlement is significant it may be an impossible problem without modification. Pump nozzle loads will be the killer, and potentially pipe stresses too.

I would recommend revising the header geometry slightly and install a double tied bellows at the tank nozzle. Alternatively if bulge is not a problem, extend the tank foundation and install the pumps on the same raft.

your right MoverZ, I will add a loop on header to elimiate bellows and high bending stress at pump suction and tank nozzle.

my question is when we are analysing above system, we have two pumps operating and one is stand-by or 1 is operating and 2 are stand by, if we consider default piping load case then are we good in calculating API 610 and WRC 107 loads?

With default load case, we assume all pumps are operating, How do we no from load case all are operating? we assume code stress are perfect and API 610, WRC 107 are with in allowable load limit with perfect summary, are this Sustain loads in default load case are good to give piping loads to civil?

Do I consider with friction one case and one case with out friction

1) WW+HP
2) W+T1+P1+F1 (WITH friction)
3) w+T2+P1+F2 (with friction)
4) w+T3+P1+F3 (with friction)
5) W+P1
6) W+T1+P1+F1 (WITHout friction)
7) w+T2+P1+F2 (without friction)
8) w+T3+P1+F3 (without friction)
9) L5-L2
10) L5-L3
11) L5-L4
12) L5-L6
13) L5-L7
14) L5-L8

Runner;
You have not shared any technical data with us so it is hard to be effective or even objective in trying to help you. I sure you did not do this on purpose.

You should give us some data (type and size) on the Tank
You should give us some data on the pumps (configuration(*)and nozzle sizes)
You should give us line size information.
You should give us pressure or temperature information on both lines.
You should show pipe supports on the discharge lines.

There have already been comments on the configuration of the suction line (which you have said you will address).
The discharge piping also should be redesigned to provide better access to the valves on the double discharge of the center pump. The new routing of the discharge lines should be done in a manner that will eliminate the flat turns in elevated pipe rack.

The rerouting of the discharge lines and the rerouting of the suction piping needs to consider the following:
- Safety (yes this is the first consideration)
- Process Function
- Operational access
- Maintenance access
- Constructability
- Proper pipe configuration for flexibility without the use of flexible elements (expansion joints).

(*) Configuration data for the pump means: end suction/top discharge, side suction/top discharge, side suction/side discharge, etc.

Dear Jop,
I appreciate your reply, My purpose is to write worst load case, for threes pumps, 1 pump is in operating another 2 pumps are stand by or 2 pumps operating and 1pump is stand-by. To know how to write load case as per above logic.

Assume:
Tank=Lxh = 24'x17'
horizontal raw water pump: suction=10" disch=8"
suction=10"
discharge=8"
Design Press=100bar
Design temp 150 F
if you see closly above pic, you find trunnion support at discharge line at elblow.

As per site condition I am checking all your consideration as you said above, you need to ask,have you considering force/displacement/Wind load/friction/hanger etc. to write load case, I don't have force/displacement/hanger etc. Reply me your load case logic I will check what worst effect is projecting out from the current routing then we do changes.

* from above pic its understood that suction is side and discharge is top.