steam turbine test 1

[SPLIT]

Please to explain the importace of asking a vaccum dynamic balance test , in a steam turbine spec.

 

[byrdj]

Is the spec for a new unit or following repairs. Also what size unit? My experance is limit to repairs of rotors 8 tons and greater.
In either case, a "low speed, static balance" spec usually will assure the rotor can be rolled to rated speed, and if performed by experance personnel, the running speed vibration will be acceptable. However, low speed balancing may not result in a balance that is statisfactory for continued operation and a balance program must then be performed. Usally the cost in cycling the plant from cold, to running condition, then back to a condition to allow access to the rotor's balanceing planes several times to do a balance will justify the cost of doing a "high speed, vacuum dynamic balance".

I am familiar with the on site balancing (a little with Low speed), but believe there are only a few places in the US that can due large (~20 ton LPs) rotors.

 

[dgallagher]

Here is a link to a good article on why one would balance at operating speed versus low speed balance:

http://www.regencoservices.com/WhyHighSpeedBalance.htm

I would recommend dealing with TurboCare in Houston:

http://www.turbocare.com/docpdf/Compressor_Tech_Article.pdf

Regards,
Dave G.

http://www.reliabilitydirect.com

 

[sms]

The other important aspect is if you have close clearance packing, starting up an unbalanced turbine rubs on and wears out packing clearance which reduces your turbine efficiency. If you want to maintain the very highest efficiency then it is best to have a very well balanced rotor prior to startup.