Reminded me this AM about the SHORT period when I thought I wanted to work at one power plant.
I had to attend a multiweek training about all the plant's systems. keeping this short, things I never knew, like barn doors,rod notching and boron injection I was aceing. THEN, they got to the turbine systems. their material had so may errors, I refused to pass those test.

In particuliar. "What is the purpose of the EH system?" correct answer "to provide cool clean (refreshing) fluid to the turbine". as I told the instructor...makes me want to take a drink of the EH!

(was actually repling to a prior post that is now deleted)

Emkel...Your illustrations are horrible in the ability to be understood and relay an actual representation

1.Regeneration device
a filtration sub sytem that could possibly have mechanical water removal and or chemical treatmeant of the EH fluid to retain its cleanliness and properties
2.Emergency Trip System
maybe a manifold of multiple solinods in some logic arrangement like 2O3 to allow indivdual testing. the purpose is to convert an EH supply pressure source in a hydrulic signal sent to the actuators to relay trip or reset status
3.Safety Oil
looks like a low {lube oil) pressure signal from some logic inside the front standands like "lube oil > X" or maybe an emergancy governor assembly. in conjunction with the diagphram valve provides addition hydrualic logic to the trip device
4.Extraction Governor Actuator
no ideal why EGA would be special

3) It looks very like the Westinghouse scheme where an interface valve dumps the EH oil to drain if the lube oil pressure falls too low.

I wonder if such basic illustrations oF a system are the correct way to learn. I think that such a simplified drawing to the unknowning would just be memorization. Only after one "knows" the system are such illustrations meaniful.

do you have the a "control diagram". While it is also a simplification of actual, but one can apply basic modeling to determine how things works.

This document from Westinghouse might be a more useful starting point for the OP than the graphic above, even if it is a non-Westinghouse machine.

Nice link Scotty. lps

Bill
--------------------
"Why not the best?"
Jimmy Carter

Good isn't it?

proud of it? where you the author Scotty?

Definitely not mine, I wouldn't dream of using a 'z' where an 's' should be.

I think it was from a nuke rather than a thermal or CCGT plant, but that .pdf was been passed around quite a few folks at my old site as an introduction to how the DEH system worked. Our own manuals weren't as descriptive.

Do I remember that you're a GE man, or am I thinking of someone else?

I noticed the NRC footer.

Yes, I mainly worked GE. now it would be the old stuff, MHC and Mark I & II EHC.

Here is My first time studying a WH type control system. through a linkedin contact, the engineer provided Control Diagram and this was my interpetation of that interface. not sure who made the unit as the drawing was in charectors and the engineers english was not good.

• http://files.engineering.com/getfile.aspx?folder=2fce8460-10bd-4e74-956b-85

In the Westinghouse document your 'diaphragm valve' is what they call the 'interface valve'. I think you've interpreted the schematic fairly accurately which is impressive considering the quality of the drawing you had to work with - the basic AST functions seem to follow the scheme in the document I uploaded.

Is it possible that some of the text is Japanese? Westinghouse licensed some designs to MHI for manufacture. Our site was a hybrid with MHI gas turbines and Westinghouse steam turbines.

after much back and forth, I did get an E size PDF. My cut and paste into the narrative was mainly so he could follow on real drawing.

I need to keep confidential what little I do have, thus the redacted sections.

the thing that stumped me for a while was the difference in how the hydraulic "trip/reset" pressure is established versus the way GE did it.

Good document, well written.

I worked for a German engine manufacturer, but I was in the UK.

Often, we could not get them to respond to simple engineering questions of 'just how does this thing work?'

An educated but time consuming review of instruction manuals and training documentations together with a close analysis of P&IDs would often give the answer!