Diverter valves in turbine-heat recovery applications 3

[Tabletman]

Does anyone have experience of diverter valve failures when you have a frame 9 turbine combined with an HRSG? I have heard many stories but need confirmation of the cause of failure.

 

[vpl]

Since you haven't received a reply, may I suggest that you repost this to the valve forum?

Patricia Lougheed

Please see FAQ731-376 for tips on how to make the best use of the Eng-Tips Forums.

 

[athomas236]

I think the reference is to diverter dampers not valves.

athomas236

 

[Tabletman]

Does anyone have experience of diverter damper failures when you have a frame 9 turbine combined with an HRSG? I have heard many stories but need confirmation of the cause of failure. Specifically Stejasa dampers.

 

[pmover]

what type of failures have you "heard of" (i.e. material failures, poor exhaust gas flows, etc.).

note this website:

http://www.mcilvainecompany.com/FGDnetoppbroch/exhibit_directory_profiles.htm

there is another mfg listed there (1st letter of mfg is 2nd letter of alphabet) that may be of assistance.

good luck!
-pmover

 

[Adam01]

You need to post this in power generating facility engineering. We have DV's on Fr6 Gas Turbines and HRSG's they are base loaded. There are a number of issues with them but all specific to design and easily fixed. Two are electric and ine hydraulic. The electric seems to be less maintenance as it is static most of the time. The hydraulic is always on when the valve is open. The oil also gets hot and degenerated quickly. It was a fire proofe product but this needed water to be added and broke down quicker that the oil.

They are all basically the same inside, ie cold casing and ss lined. quality of the liner installation is important. The valve is also where the opening is for the purge air fan (duct fired HRSG). The door is a knife gate type valve with air seals. The seals need repair but this is infrequent. The valve is sealed in the open and shut position with 2 rows of ss flaps on the valve plate and casing. The two rows form a void which is pressurised with air (at low pressure but higher than the air flue as in the HRSG). This ensures no loss of flue gas up the stack. These ss flaps need repair at every opportunity we get as the bend/buckle or make contact with teh side wall liner plate pins when valve opens/shuts.

The greatest problem is the valve bouncing in the combined cycle position. This takes it off the closed limit and trips the GT. This has happened perhaps 4 times in 9 years.