AST maximum inlet pressure 2

[Faster7]

dears we have new atmospheric storage tank and we want to install a protection against high inlet pressure and flow.
how can we calculate the maximum pressure at the inlet of the tank?
take that we have old atmospheric tanks on the pipeline terminal and the designer put 5 bar is the maximum pressure when it reach that the safe guard shutdown the pipeline.
is there any guide lines or rule or thump on that?
additional information:
the tank is external floating roof, capacity 236000 m3

 

[TugboatEng]

5 bar at the bottom of the tank, correct?

 

[Faster7]

the 5 bar setting is on the inlet of the terminal from the pipeline.

 

[TugboatEng]

The tank isn't sensitive to inlet pressure. It's sensitive to internal pressure. With sufficient venting there should be no contribution to internal pressure do to inlet flow.

 

[Faster7]

that mean even high pressure from feeding line will fall down to atmospheric pressure when released inside the tank?

 

[HTURKAK]

- The inlet pressure would be the height of liquid content for atmospheric tanks..
- If you say 5 bar maximum inlet pressure , literally means , tank ht is more than 50 m ( if the content is water )
- I think the capacity should not be 236000 m3 ..( almost 1,500,000 BBL ??) Will you pls provide the details of the tank ?

 

[LittleInch]

An EFR is basically an atmospheric tank plus the hydrostatic head. There is small extra pressure caused by the weight of the roof, but this isn't significant.

So the pressure at the entry nozzle in ABSOLUTE pressure is Atmospheric pressure plus the head of the liquid in the tank.

your tank is a 1.5 MBbl tank (!!) So basically HUGE. but still probably no more than 18 to 20m high.

So your pressure, assuming you are at sea level at the inlet nozzle is less than 2 barg when full.

What the pressure rating is upstream of your tank isolation valve is up to you. A pressure of 5 bar is a nominal operating pressure, but normally the design pressure is the same as the flange class (class 150), so up to 19 bar. if I was asked to provide a maximum operating pressure for a terminal downstream then I would choose 5 bar as the figure to set the pressure regulating valve from the high pressure pipeline. More than enough for frictional losses / losses across filters etc, but would normally expect it to be 1 to 3 barg.

The tank nozzle downstream of the isolation valve and the tank itself will only ever see the hydrostatic head from the liquid in the tank.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Faster7]

thank you for your valuable response
appreciate that