NOISE IN PIPING OF CENTRIFUGAL COMPRESSOR COOPER AT THE 2ND STAGE

[32c4]

WE HEAR A NOISE IN THE M.P STAGE PIPING SPECIALLY WITH VIBRATION AT THE COMMON SHAFT OF B.P AND M.P WITH SENSOR ON LIGNE ,but Nothing with off ligne vibration what is the phenomena ?

 

[georgeverghese]

We know MP is medium pressure, but what is BP ?
Pls post a process PFS / P&I D or or hand sketch of this compressor. What service is this machine in - some further description of driver, compressor, process gas and conditions will help also

 

[32c4]

EXCUSE ME BP IS LOW PRESSURE SUCTION L.P (BP IS IN FRENCH BASE PRESSION)
this compressor will compress the propane that is boiled off from a large storage tank of refrigerared liquid propane gas.
the problem when we start the COMPRESSOR we have a noissy sound at the medium stage piping with a vibration witch rise gradually in installed on line probe but no vibration with off line apparatus vibration
we have like flow instabillity or circulation .
salutation

 

[georgeverghese]

Cooper 3stage multistage compressor - integrally geared. There is an intercooler between stage 1-LP and 2-MP.
From what you describe, since there is no vibration on this shaft when compressor is offline, and that vibration occurs on startup only, I would guess intercooler tube leak. Water accumulates on propane side (shellside?) of this cooler when compressor is stopped, depressured and cooling water is still running through intercooler.
Does vibration on this shaft disappear after a few minutes of running ?

 

[32c4]

WE FOUND SERIOUS DAMAGE ON THE FIRST STAGE IMPELLER ( photos attached)
with a metallic debris in suction line or piping of the compressor.
the question from where they come this fragments of metal?
before entring the gas compressor we have filter and then flow control valve (Valdisk BX Control Valve)
and also a fragments of Teflon and PTFE.
SALUTATIONS

 

[32c4]

DEBRIS OF METAL

 

[LittleInch]

Thermowell snapped off?

Other type of probe?

What instrumentation is between the filter and the compressor?

That's some pretty neat damage alright.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[georgeverghese]

What type of filter, and what was pressure drop across filter just before failure? Is there a high differential pressure alarm at filter?

 

[pierreick]

Hi,
Can you share with us a PID of the unit? Only you can see whether parts are missing to explain the damage on the rotor. What about interlocks? all in place prior to shut down.
Anyway, time to get contact with vendor/manufacturer for an overhaul and experience sharing.
Good luck,
Pierre

 

[32c4]

Hi
pressure drop 0.23 bar
control Valve Model:Valdisk BX flowserve
type filter :conical with internal mesh

but it is situated before the control valve

 

[LittleInch]

Is this an internal pipe filter (top hat / witches hat?) or a proper filter you can open and clean without removing the pipe work?

Is the filter still intact?

The typical commissioning strainers / filters are about as strong as a paper bag...

And why do you have a control valve on the inlet?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[32c4]

Yes it is a internal pipe filter (conic with mesh )

the filter is not yet open
and also the control valve not yet inspected or dismantel
only the control valve internal accessories witch are on contact direct with inlet compressor

control valve in the inlet is for regulating the fuction of the compressor

why the filter is first and then the control valve?

because this debris was found in the pipe conduct suction

 

[georgeverghese]

0.23bar for conical strainer may be too high - it may have ruptured and mesh wire may have torn off the teflon seat on the control valve?

 

[pierreick]

Hi,
Attached a document from Cooper to understand the query from OP.
I will be interested to see the internal part of the valve (lamellae *), probably partially gone!
* ventelles in French.
ref page 9 of the brochure to visualize a missing sketch or PID.
Good luck.
Pierre

 

[32c4]

Hi,
After dismantling the butterfly valve (control Valve Model:Valdisk BX flowserve)
we found the spiral wound with SS outer inner ring damage ,deterioration of the gasket it was the main cause of the problem
the choice of the gasket was not right 12" Instead of 14", so the inner ring was not centrend and enter in contact with disc at each starting of the compressor until the cutting of the half inner ring and drawn in the impeller.
I think it was well explain
see you friend's

 

[LittleInch]

Well 14" is a bit of an odd size. Surprised it actually sealed though.

At the same time take a look at your filter if you can. Personally I hate those witches hat type filters as they are very difficult to remove and can easily break.

Those fragments in the other photo though look like something else and not gasket related. Possibly two different things? Please check your filter and other instruments between them. Could also be parts of the compressor?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[georgeverghese]

Okay, presume Cooper wont cover you for the cost of repair/replacement parts in the compressor for this oversight.