Servo valve Moog installation

Hello everybody,
I need some information about, moog installation, since commissioning our frame 9 turbo generator set with mark6e TMR has had an oil leak at the servo valve (Moog whose photo is attached with its support) when dismounting the servo valve we noticed that the support of this servo valve is different it contains only 3 holes instead of 4 holes like the other frame 9 groups with Mark5 TMR as control system. Please whoever has an answer explains to us because we are thinking of replacing the support.
 

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GREAT question for GE in Belfort, France.

But it doesn't appear there is a on o-ring in the unused port--which would prevent leakage. Have you tried installing an o-ring? What was the result if you did?

Is the servo-valve working correctly otherwise?

What is the servo-valve installed on?
 
Thank you very much WTF for your answer concerning the o-ring it was there but as there are even leaks, the servo valve was installed on the SRV valve and works perfectly but with oil leaks. We wanted to know if it is necessary to replace the support with another with 4 holes or even with 3 holes it works well, attached a photo.
 

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The “support” is usually called a manifold block and has internal passages for porting the hydraulic oil to the actuator as necessary. The servo may be a multi-purpose servo but the fourth port is not required for the SRV. If the SRV is working perfectly it would seem the fourth port is not required for any purpose. The mere presence of a fourth port that doesn’t conduct hydraulic oil anywhere wouldn’t seem to be the answer to the problem.

What material is the manifold block made of?

Where would you obtain a new manifold block?

Have you checked to make sure the manifold block is flat and doesn’t have any high or low spots particularly in the area of the unused servo port?

Have you tried contacting GE Belfort? What was their response?

If GE Belfort was not the packager/supplier of the machine have you tried contacting the packager/supplier for assistance?

Does the actuator have any manufacturer nameplate? If so, you could try contacting them to ask your question.

While it’s unlikely it’s not impossible the mounting surface of the servo is not flat. Have you tried contacting pl for assistance with the problem?

Have you tried replacing the servo with another?

That’s all I can add to this thread. The packager/supplier of the machine would be the best resource, and the manufacturer of the SRV actuator would be the next best resource, with MOOG being another good resource.

Please write back to let us know what you learn and how the problem is resolved.
 
Good day WTF,
The manifold block is made of steel
Currently we do not have another manifold block but we plan to request one from the manufacturer as part of the punch list
The surface of the manifold block looks perfect
We replaced the servo with another but it didn’t solve the problem
GE Belfort sent its technicians three times but they could not solve the problem
We didn't think of contacting the manufacturer of the valve or Moog because the problem is treated within the scope of Commissioning punch list with GE Belfort.
Here attached a photo of manufacturer nameplate.
Thanks

 

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Soooo, this is a Woodward-manufactured valve assembly using a Fisher valve, probably a Cam Vee-Ball valve. Woodward actuators and valve assemblies have proven to be very problematic, many requiring yearly refurbishment. AND, they have to be returned to Woodward for refurbishment or repair. Great deal ... for Woodward.

"The surface of the manifold block looks perfect"

A good mechanical maintenance person can determine pretty quickly if the surface of the manifold block is perfectly flat, or not. Visual inspection may not be good enough, and usually isn't.

Okay, you're going to request another manifold block from the manufacturer as part of the punch list. But, you haven't contacted the manufacturer about the leak problem--or had GE contact the manufacturer about the leak problem.

It's entirely possible Woodward used the wrong manifold block--but it's also possible they used the proper manifold block but it's not flat. Again, Woodward quality control on gas fuel valve assemblies manufactured for GE hasn't been the best over the years. GE squeezes every vendor for the lowest price, and then squeezes them some more. There is a reason GE buys gas valve assemblies from Woodward, and Woodward makes lots of money refurbishing and maintaining the valves they sell GE. And GE doesn't care as long as the cost doesn't come out of their bank account. (The valve assemblies manufactured by Young & Franklin mostly lasted decades before needing refurbishing. And the valve assemblies MOOG manufactured for GE were also pretty robust and reliable.)

This is not a controls-related problem. The Mark* doesn't control leaks from servo-valves.

Best of luck with your problem.
 
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