Blanketing

The best source of information is either the Process Description document or the HazOp Study Report, available locally. After all, the materials in the drum and their temperature have not been posted.

The liquid is Lean amine.

This is part of a system that uses Methyldiethanolamine (MDEA) to remove Carbon Dioxide and Hydrogen Sulfide from sour gas and other hydrocarbons. You may get some idea of the process here: http://www.simtronics.com/catalog/spm/spm3100.htm

If this is just a matter of satisfying your curiosity, you should find answers to many of your questions by using a search engine like Google. If you have been made responsible for this process without having undergone enough training to let you know what it does and what the hazards are, you should get a job somewhere else.

You are working with Hydrogen Sulfide, which is more toxic than Hydrogen Cyanide. A careless or casual approach to anything that has such a potential to do harm is at best dangerous, and at worst, criminal.

A careless or casual approach to anything that has such a potential to do harm is at best dangerous, and at worst, criminal.

Very wise words, please tell me this system is covered by a formal Process Safety Management (PSM) program or an equivalent no matter what country it's in.

Learning is great but seriously don't touch anything or tell anyone else to.

PCV-1 ,Fisher model 166 comes only in 1-1/2" and 2" size.You show 3/4",may be my catalog is old.

PCV-4 series 66 is a downstream regulator,so I can not fathom it's use as shown.

To answer your question as to how it works.

In the system I set up long long time ago (1985) in the place of the 1/2" globe valve shown between PCV2 and PCV 3 I had a fisher fine needle valve with a flat cover.One had to open the cover with wrench and then have a special tool to adjust the opening of the needle valve.The intention was to prevent unauthorized adjustment.

The scheme shown is to control the blanketing pressure on the tank to 1/2" Water column.

When the blanketing pressure is 1/2" WC ,all valves are closed.

When the pressure goes below 1/2" of water, PCV3 opens and fuel gas goes thru the PCV2,the correctly adjusted needle valve, and thru PCV3 to increase the pressure in the tank to 1/2"WC.

For very small flow requirements (like ambient temperature falling) what I said above will happen.

But if a pump is started the pressure would drop and the PCV3 would go more open and because of the adjustment of the needle valve the pressure upstream of PCV 3 would go below 17" H2o and now the big valve PCV 1 would open to admit large quantity of fuel gas to bring back quickly the presure back to 1/2"WC..

These system can control the blanketing pressure to within 0.1 " WC of set pressure.

It is important to adjust the needle valve correcly to prevent the big valve PCV1 from opening only when needed.

Let me know if you find out why PCV4 uses model 66.

Thank you Srini.