Steam turbine labyrinth seal

[migueldiazch]

Hello

Have any body have installed 4 part labyrinth seal instead of 2 part?. These is because due to external leakage we are planning to replace the labyrinth seals and after checking them we noticed that the new ones have 4 portions and the old one have 2 portions; beside that difference, everything is Ok.

The steam turbine is a Coppus model RLHA244IN202COPPUS.

Regards,
Miguel Díaz.Due to vapor RLHA244IN202

 

[byrdj]

I don't recall ever seeing 180 degee segments, it has been 4 segments or more. However the smallest rotor diamater has been about 12" that I have seen

As long as the ends are machined at the proper angle and the supplier provides you with the proper butt gapp clearances, I would think 4 piece would be better than 2 since this would allow more contact with the hook fit, which should establish your cold radial clearances.

IF your design does not utilize hook fits, but some type of a floating ring, the 2 piece might be better, but a 4 piece should suffiece

 

[byrdj]

Intersestingly, the information from a google search calls for 3 piece carbon seals?

 

[Ralph2]

I would wonder how the new splits.. top and bottom would seal. with 2 the splits are horizontal... in line with the casing and one can determine better the crush or lack of.
But there are lots of designs that have multiple segments.. where each segment is held towards the shaft with springs under the segment. which slides in a tee groove

 

[ijaz128]

we are also using 4 parts seal, quater circle, two at bottom and top.

if you talking about stages then they vary