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[M.Sadiq]

I need your favor & guidance regarding the following issues:

1) Three Phase Separator:

Regarding the sizing of separator, normaly the following Droplet Size is considered to separate out from each stream.

* Oil in Gas = 100 micron (Mesh Pad Inlet)
* Oil in Water = 500 micron
* Water in Oil = 200 micron.

I know the above droplet sizes is dependent on the downstream process requirement i.e., separated gas fed to compressor(where 10-5 micron removal is usually carried out through separator) etc.

But in my case the separated gas is fed to another separator (filter separator) while condensate is pumped to the column & separator produced water is directed to the degassing boot & then CPI Separator.
in this situation what droplet size to recommended to seprate out ??

From GPSA & other refernce i found a Chart where micron size removal for different catagories is specfified.

For Sparated Gas, using GPSA chart, if i use 50 micron oil droplet removal from gas then the size of the separator is too BIG!! & when when i use 100 micron droplet removal the size of the separator is drastically reduced. In this regard please guide me which droplet size removal is to consider ??

For Separetd Condensate, i m bit confused to select the droplet removal size of water from oil. If i select 200 micron droplet size the i need a less retention time & ultimately Less Volume of vessel for separatoin of water droplet. But when i use 100 micron removal then i need too much retension time & BIG Volume is required for separtion . Please guide me ??

For Water side, oil droplet removal(500 micron) same thing happened (as mentioned in condensate case) when i select 500 micron removal of oil droplet from water.
Please Guide me which micron sizes(oil in gas, oil in water, water in oil) i use for separator sizing .. Any design practice or Standard ??

2) Line Sizing:

From API 14E, for liquid phase the velocity to be maintained between 3-15 ft/sec. For gas phase, mini. velocity is 10-15ft/sec while max. velocity should be below 60 ft/sec to cater noise problems.
For Mixed phase, mini. velocity is 10-15 ft/sec while max velocity to be kept below erosional velocity. Most process engineers recommend that mixed phase velocity should be kept below 70% of erosional velocity. but i search alot to find the refernce of any standar or design practice. please share if u know ..
Thank !!