Gland Seal Flashcards
What are the steam sources for gland seal?
Main steam, aux steam, LP 9th stage extraction turbine
What does gland sealing steam do?
Prevents air leakage into and steam leakage out of the main turbine and the feed pump turbines via the shaft glands.
It returns the air/steam mixture to steam packing exhauster where it’s condensed and returned to the condenser while air and noncondensable gases are vented to atmosphere
What pressure is gland seal maintained at?
4 psig
Which steam regulator valve opens first and closes last?
PV-28B extraction steam supply valve.
What makes up the steam packing exhauster?
A shell and utube HX and 2 exhaust fans.
What cools the steam packing exhauster condenser?
TC
Why do we have shaft packing on the turbine rotors?
To keep the steam in and air out.
What does the steam packing exhauster unit do?
Maintains a vacuum on the steam exhaust header and annulus between the middle and outer shaft packing rings.
This prevents steam from contaminating the journal bearing oil
Describe PCV-27.
Auto acting back pressure regulating valve that does not require IA to function. Excess dump valve.
What supplies gland sealing steam at full power?
28a & 28B are closed and HP turbine shaft packing leak off provides most of the sealing steam requirement. V27 unloads any excess steam to the main condenser.
