Throttling Strategy for Steam Process

[piyush007]

ohk, let me make it more clear for you,
the situation is we have a boiler generating steam at 23.5 barg, which is throtlled down to 12 barg for import/ export, this 23.5 barg steam is throttled down to 3 barg by another valve to use in heat exchanger, and then this 23.5 barg steam is throttled down to 0.20 barg to use in deareator by another valve, so i was thinking if we have a a system such that we throttled down 3 barg steam to 0.20 barg steam, then that would be beneficial as in, the pipeline will need less permissible safe wroking pressure, less heat losses due to radiation, no need of high pressure valves for throttling etc.
But then to make a new pipeline will require cost analysis, and hence i wanted to know what calculation can i do to prove that throttling 3barg to 0.2 barg will be beneficial in terms of profitability.

 

[manderson99]

Not sure if I can help you in any meaningful way here, but let me try rewording this so I understand it myself:

You have a boiler that is generating steam at 23.5 bar gauge pressure. You currently have three separate valves permitting steam to escape the boiler.

One valve feeds the import/export line (12 bar gauge)
One valve feeds the heat exchanger (3 bar gauge)
One valve feeds the deaerator (.2 bar gauge)

So are you considering feeding the deaerator using the steam flowing into the heat exchanger?

 

[Vedward]

The pipe sizes are based on flow requirements (mass per unit time or volume at pressure per unit time), not the pressure at the point. At the pressures you note, all the piping would be standard, low pressure. But if lower pressure steam is run to other points, the pipe size may have to increase.