Instrumentation - Design for LP Separator with PSH and LSH

<...how it shut the LP separator inlet valve when there is a PSH and LSH...>

If S were to stand for "switch" instead, then it becomes quite simple. Each device, when the process parameter goes from the normal to the high condition, opens a contact that, when closed, holds the LP separator inlet valve open.

There may be a bit more to it than that. Look for three documents: the first is the HazOp Study report, the second the Control Philosophy document written by the Process Design Engineer, and the third is the Functional Design Specification document written in response to it by the Controls Design Engineer. The detail of the arrangements will be found within at least one of the three.

<...what are the steps taken:Basically,the flow station has a line heater hp separator,lp separator and a st orage tank but this time there will be an upgrade so tthere will be an addition of surge vessel,water treatment plant,gas scrubber,pumps and test separator...>

The detail of this will be found in at least two of the three documents above.

The document I have is the symbol legend sheet,cause and effect matrix,control panel schematic-ESD and FIRE Module,HP separator module and LP separator module.Please PWSlack which API standard or design parameters should I used to design the for the upgrade.Thanks

It can't be done without the "approved for construction" Control Philosophy and the same-stamping P&IDs, both of which should have been passed through the HazOp Study before approval.

Stop work until these documents are to hand, otherwise it will all end in tears.

>PSH(Pressure Safety High) and LSH(Level Safety High)

PWSlack's observation is almost certainly the case; PSH and LSH are almost certainly Pressure Switch High and Level Switch Low, by ISA-5.1-1984 (R1992), Formerly ANSI/ISA-5.1-1984 (R1992), section 5.3.

Yes,I have the Upgraded P&ID that has Test Separator,HP,LP,Surge Vessel,Settling Tank,Storage Tank,Water Treatment Plant.The information I need is the design parameter basis I need to design a pneumatic control for the aforementioned.Please send me your mail so that I will send you the P&ID I developed.Thanks

Declined.

The Client needs to approve the P&ID "for construction", and the Process Engineer needs to write the Control Philosophy before any further work takes place. Otherwise it will all end in tears, as indicated earlier.

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The Client has approved the P&ID for construction and the control philosophy has been written by Process Engineer.So what is the next step.

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Write the Functional Design Specification, and pursue approval.

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Please can you design this kind of pneumatic panel.