High gland steam header pressure issues

I am a steam and boiler tech. Could send more info....I would love to come to India and help solve your ploblem.

It sounds like the high pressure turbine labyrinth seal clearances are rubbed out or the gland seal system spillover valve is faulting shut. I'm using what little information to develop this. Perhaps a better explanation of where the pressure reading is being taken. Also, is there steam blowing from the low pressure turbine element glands?

Steam, Cinders & Smoke

I got on to this site only today - even so, here are my two cents ... for what it is worth. There is another scenario, besides the possibility of worn seals/ excessive clearance that was suggested before.

As you may be aware, there is a control valve feeding main steam to the (gland steam) header. Its function is to provide steam for sealing glands at no-low or low-load. Once the Unit is up, this valve needs to shutoff tightly; the steam from HP/IP glands is sufficient to seal the LP turbine glands. It is likely that this valve is leaking ... to the extent that dump valve, which relieves the header of any excess pressure has run out of capacity. The solution requires 2 main things: (1) a tight shutoff gland steam supply valve. Shutoff thrust of 1000 PLI (pounds per unit inch of seat ring circumference) minimum gives good long-term performance; (2) velocity control trim in the valve to minimize damage to the seating area during throttling.