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filling a floating roof tank

filling a floating roof tank

filling a floating roof tank

Hello everybody,

I want to ask a question.
Can I fill a floating roof tank through the output nozzle?
Knowing that the output nozzle has a vortex breaker.


RE: filling a floating roof tank

Sure. Until the roof is floating and the liquid is at least two pipe diameters above the inlet pipe, limit the flow so the velocity in the pipe network leading to the tank is less than 3 feet per second. If it is faster, evaluate for static charge accululation. If the fill pipe is pointing towards the tank bottom, evaluate for erosion and erosion corrosion. If gas could be in the inlet stream (from pigging, blending, etc), evaluate the situation for floating roof damage. If the pipe is pointing towards any part of the floating roof, evaulate for floating roof damage. If the pipe is very close to the tank shell, evaluate for splashing or turbulence that could get past the floating roof seal(s) and wind up on top of the floating roof.

RE: filling a floating roof tank


Do you mean initial fill before the roof is floating or in normal operation?

A diagram / drawing would help a lot here, as well as size, flowrate, product, velocity etc, but in general you need to be carful that the flow doesn't break off the vortex breaker or result in erosion of anything or generate lots of vapour if you're doing this as part of initial fill.

And why can't you use the inlet nozzle?

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

RE: filling a floating roof tank


We have two tanks, the first tank supplies the second tank (media pyrolysis gasoline) in the normal operation.
Currently, the plant is in total shutdown and we want to install a new radar system for the second tank.
So, we want to empty the second tank by transferring the remaining gasoline to the first tank without modification.
Operation people propose to transfer the gasoline through the existing line between the two tanks.

That is a brief description of the matter.

best regards

RE: filling a floating roof tank


Thank you for your cooperation.


RE: filling a floating roof tank

I don't see any problems inherent with this idea but do youknow the flow rate, line size and initial liqhid level in the first tank? When the second tank is nearly empty, will the pump push vapors into the second or will it just lose suction?

RE: filling a floating roof tank

More questions than answers here.

So flow goes fromtk1 to tank 2 Yes?
How? By gravity or pump??

You want to empty tank 2 back into tank 1.
How? Pump?
So the back flow is into tank 1 which has a fully floating roof.
If the velocity is kept pretty low (1-2m/sec) you're probably OK, but a lot depends on what the vortex breaker loos like - Do you have a drawing or can you sketch it?

So long as your roof plates are more than say 2m from the end of the outlet nozzle if it points upwards then you should be OK.
If it points horizontally then maybe even lower.

Some drawings would help!

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

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