[Amir]

The model number of our gearbox is P2195.

Yes, we found the source of the leak. It is from our output shaft due to collapsing the V-seal on the oil tube/dam. This v-seal is not submerged and is only prevents splashing of the oil to the out shaft and seal. Now I have 12 of the 15 gearboxes leaking. To get to this V-seal we need to completely disassemble the gearbox. Note this is not part of normal PMs.

Amarillo has failed to give us a convincing answer of why the seal is failing.

Just heads up this is not the only problem we have with these gearboxes.

[Amir]

The model number of our gearbox is P2195.

Yes, we found the source of the leak. It is from our output shaft due to collapsing the V-seal on the oil tube/dam. This v-seal is not submerged and is only prevents splashing of the oil to the out shaft and seal. Now I have 12 of the 15 gearboxes leaking. To get to this V-seal we need to completely disassemble the gearbox. Note this is not part of normal PMs.

Amarillo has failed to give us a convincing answer of why the seal is failing.

Just heads up this is not the only problem we have with these gearboxes.

[Amir]

Scattergood Generating Station is located at El Segundo, CA. I called Amarillo and sent emails and no responses. Please share your email address and I will forward you all the info and V seal picture.

We change the oil every other year using synthetic oil and every other year we are filtering the oil. We also take frequent oil samples.

Thanks a lot,
-Amir

[Amir]

I have contacted Amarillo.

I am wondering after the oil level comes down below the drywell, why the leaking does not stop.

Does the seal compromised after the gearbox being overfilled?

[Amir]

Hello All,

We finally found the leak!!!

We got a He hit on a drain from STG #1 Bearing Packing Head/LP Head drain. (see my comment on May 4, 2017 at 9:29 pm). The #1 bearing housing/head is located in the exhaust tunnel. We disassembled the housing/packing head and found all the joints were not sealed properly and the contractor didn’t torque the bolts to the spec and not enough RTV applied to the surfaces. We found no damages to the steam seals. Note: Our combined cycle was commissioned about 18 month ago.

After we started the combined cycle, our vacuum went to normal. This is a very hard place to find the leak cause there is a great chance there will be no hit on the drain. We believe the air got into the #1 bearing housing (which suppose to be under atmospheric pressure) from the oil lines cause we tested all the other connections. This is something for A14 users to look into in case they have vacuum leak.

I greatly appropriated you all comments and feedback.

[Amir]

We did as much as we could including all the expansion joints and from turbine exhaust all the way to ACC.

Thanks a lot,
-Amir

[Amir]

We sprayed all over the bellows and didn’t get any indication.

[Amir]

We did check the ejector condensate traps. I am going to have them flushed again.

We found indication from drain on the bearing housing/seals. We thought it is the steam seal, then we increased the seal steam pressure to 7 psi and nothing changed. we put a bucket on on the bottom of the drain and we filled it with water but the Helium indication is gone but the vacuum problem is still there. On the next outage we will look at our N1 bearing housing (We have A14 unit) to make sure there is no leak there.

The low temp issue is on all cells and they move around. We could not point it to any specific cell. As the hogger comes on the cells get better but the cold temp start developing randomly again.

I have not used ultrasonic for this application. I can look into it.

Thanks a lot,
-Amir

[Amir]

Few weeks ago, when the leak/issue was not as bad, we brought the pressure to 3.2 inch and then isolated both the hogger and jets. Then we let the pressure rise to 3.8 in and we timed it. It took 90 sec. Per OEM this should take 20 minutes.

The other test was I had the jets and the hogger run in parallel and we still could not get the pressure to go down. Then we had the hogger on manual with all the jets isolated manually and the hogger didn’t bring the pressure down to the spec which we used to get to 3.5 in.

[Amir]

Yes, we checked all the areas below the LP section and exhaust.

[Amir]

Yes, we did, We sprayed Helium at a drain downstream of the hogger when it was off and we didn’t get any hits. We had the exact same issue as you said in our 2+1 unit few weeks back.

Thanks a lot,
-Amir

[Amir]

We don’t have inlet heaters and I am not familiar with them. What are they for?

We did spray all over the tube bundles with no hits. We used long tubes to reach them.

We keep our PH on our HRH between 9.6-10.4 and the same on HP drum. We are using AVT program and only injecting Ammonia.

Thanks a lot,
-Amir

[Author]

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