Rod drop affected by bad or leaking packing.

[RecipAnalyst]

Hello everyone,

I am an recip analyst for a pipeline here in south Texas and have run across a unique
issue. On one of our 3 throw compressors the #1 throw is tripping the compressor on high
rod run-out thru their Bently system. We were seeing up to 50 Mils ! The vibration
SME for the job verified that the system form the Mod to the throw was ok. He then installed
a new cable and probe independent from the system to verify the rod was really raising up that
high. It was. We found that the packing was leaking and worn so it was changed. After the repairs
the rod drop was down to 7 mils. So my question is, how on earth can a packing do this? I've never
seen this before.

Ever.


Feed back anyone?

William Lewis
Compressor Analyst Level II
Vibration Analyst Cat. II

 

[dcasto]

See if this helps

http://site.ge-energy.com/businesses/ge_oilandgas/en/prod_serv/serv/downloads/monitoring_piston.pdf

 

[RecipAnalyst]

dcasto

That's some good info. We are inspecting the cylinders now and pulling valves.
As far as debris or liquids this does not seem to be the case. We replace the
packing on throw 1. Now the alarms are coming back in on 1 and 2. We just love
it!

William Lewis

 

[bcs5274]

rings and rider bands good, is there enough gas flow thru the cylinder to keep piton centered in bore?

 

[RecipAnalyst]

Pressures are good. Bently is corrupted it turns out.
We rebuilt the compressor due to PM time and found trash in throws two and three.
I will update as more info comes available.

William