Steam seal regulator
Steam seal regulator
(OP)
Commissioning a rebuilt 1950s GE turbine with orginal steam seal regulator. Apparently working fine for 2 weeks, now gauge on it shows no pressure. No steam leaking at the seals. I suspect the guage is bad. How can I check while online?





RE: Steam seal regulator
RE: Steam seal regulator
There should be a least a couple taps (with isolation valves availabe to to you. More than likely the gauge you use to look at will have an isolation, then a plugged tee for installing a test guage for calibration ( or as a check guage.
You didn't say if MSTG or LSTG regulator, but in either case the feed and dump valve are operated by one summing lever. If that lever is level, then both are closed.
while off line or below minimun load the lever will be tilted to open the feed and supply main steam to the seal header.
Once on line and above minimun load, the HP gland leakage will back flow into the header, the regulator will sense the increase seal pressure and close the feed and open the dump valve and the lever will be tilted with the other end up.
For the LSTG, the dump valve opens with the hydrualic actuator piston down. For the MSTG, with the actuator piston up.
IF you have any other questions related to those MHC controls, please ask
RE: Steam seal regulator
If the regulator fails it will NOT be with both feed and dump closed, it will be with one wide open. Thus a full dump of the header, or an over pressure feed condition
RE: Steam seal regulator
We chased a condenser air leak for years until it was noticed that the problem was intermittant happened only at minimum (overnight) loads (which didn't necessarily happen every night) and upon examining the heat balances looking for what piping went under vacuum only at low loads, the SSR piping was found to operate under vacuum at the lowest heat balance, and lo and behold, there was a loose flange that I had seen mentioned in an outage report several years previously but that had never been tightened. At higher loads it leaked steam, but at low loads it sucked air. There were enough serious steam leaks around that unit that the low pressure SSR output didn't get much attention.
Tightened the flange and the problem went away.
rmw
RE: Steam seal regulator
I did a little research and the LSTG isobar regulator was not introduced till 1951. I just can't remember working on a LSTG SSR pre 1951's design.
As far as the MSTG, while it is not a true isobar, it should have had a very narrow regulation, but I don't know when they were introduce or the vintages I've worked on but all Lynn's looked old to me anyway
RE: Steam seal regulator
I have worked 37 nights straight and have convienced them to let me go to a 4 & 4 rotation. This is my last night and I really don't care right now. I will check back with yall on the 8th.
RE: Steam seal regulator
I believe you will have the "door spring" set point adjuster. And the regulation is a function of spring load at set point and its gradiant. with a higher header pressure required to open the unloader with higher load.
I believe design regulation was 2psig at NL and 4 psig at FL,with an acceptable operation of 0.5 psig at NL and 8 psig at FL
IF the manual control handwheel works down and makes contact with the cover it will prevent the unloader from pinching down as load is reduced and cause a header pressure drop
Boy that brings back unpleasant memories bent over under the deck flooring on the right side
RE: Steam seal regulator
rmw
PS to byrdj-the SSR section was my only "F" during my FEP.
RE: Steam seal regulator
...have you found http://turbinecowboy.com/...
jfb, FEP 1979
RE: Steam seal regulator
rmw
RE: Steam seal regulator