Balluff linear transducer failures

Q

Thread Starter

Qarsaan

I have received a report of several failures of steam turbine governor & stop valve position feedback transducers. The transducers are Balluff make, model BLT-5-E17, installed in a Siemens SGT5-4000F CCGT plant.

The problem seems to be temperature related, with the devices being overheated by heat conducted from the valve bodies.

I was wondering if anyone else out there has similar experience.
 
M
This failure is caused by high temperature inside steam turbine noise enclosure. You can changer design of the ventilation system of this noise enclosure. Increase the number of air inlet and air outlet in surface. The Liner position transducer permissible temperature max. is 60 degree C.
 
Thank you for this advice.

Do you know if this has been done successfully anywhere?

(My thought is the failures are mainly due to heat conducted from the steam valves, and changes to the ventilation arrangement might not be a long-term solution.)
 
There is also another reliable company that produce the same transducer, it's name is Gefran and the RK model have standard temperature up to 90°C.
 
R

Richard Mick

Balluff has had quality problems with the linear product in the past. Your application might be an issue/cause but you might want to challenge the factory findings and have them prove it to you and verify the exact cause of failure.

> I have received a report of several failures of steam turbine governor &
> stop valve position feedback transducers. The transducers are Balluff
> make, model BLT-5-E17, installed in a Siemens SGT5-4000F CCGT plant.

---- snip ----
 
B

Bhadresh Chauhan

Hello All,

We are having same machine SGT 4000F GT CCPP and we have also faced lots of problems of Stema turbine Governor and Stop valve Linear Position Pick up failure. We have also Balluff as a Position Pick up. We observed two issue for the Failure.

1. While analyzing the problem we found that the capacitor inside the Balluff transmitter are frequently failed. we wrote to OEM for analysis and thye said the Balluff installed at your site are older version. you need to change the balluff with New version which are more reliable.

2. Old version balluff failure is also due to Temperature rising in the vicinity. we did one experiment in running unit. we had problem with tow balluff with hunting problem. hunting in the value occurred in Afternoon during 3 - 4 PM while temperature is Hot. as soon as hunting started we put wet clothes on the balluff and after two -three minutes hunting stoped. then we have also put one portable air source near balluff and hunting problem stop.

so according to my observation you need to check your balluff version(serial) number. if it is old version than please change.
 
We have also faced the same problem of Balluff linear transducer failure (BTL5) in our Steam turbine generators due to temperature.

We have provided VORTEX cooler tapping in partial close canopy type arrangement made from glass wool & covering Balluff transducer electronics to limit the heat nearby Balluff & circulate the cold air around it for maintaining temperature in working limit of Balluff. This works well since last 2-3 years without any failure.
 
J
Good morning Gents,

In the past 2 months, We had 4 failures of this type on BALLUFF BTL-5, installed on steam turbines.

As those happened with 2 different BTL5, I am also suspecting temperature.

It is suppose to work up to 85 °C, I measured the actuator temp before the incident, it hardly reaches 55 °C.

What kind of T° were you measuring on the actuator before your failure? And what is it now with your cooling system?

Thx
 
B

Bernd Schneider

Dear julekogurek,

Balluff is providing a global service network. We kindly ask you to contact us: [email protected] +49 7158 173 370 or check www.balluff.com --> country --> contact --> technical support.

Hope this information is of help.

Best regards,
Bernd Schneider
Industry Manager Energy
 
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