Is there any adujstable control regulating valve (flow) INSTALLED...to maintain vacuum set in the oil tank

 

The unit since commissioning is running with slight positive pressure at LO tank. The unit was handover in that condition to Operation team.
Last LTPI we checked everything internally. Changed cartridge filter.
After startup still it was same. Adjustable valve was tried after startup, but there was no any change in vacuum. After that never got a chance to check anything.
Unit still as its is because it never reached the trip point of 50mmh20 at LO tank

 

To check bypass line we need shutdown as it's internally located.
as the system is new for operation, We are not very familiar with the mechanics. We will try to do with pid support in next opportunity.
Last time most of the things was checked and verified by mechanical maintenance team.

 

Okay
Thx for keepin us updated...

 

I'm working in FRAME 5 MS5001 Gas turbine, I have observed while increasing the load LO tank vacuum reduces.

Increasing load increased temperatures of bearing, this will increase LO temperature and resulting in generation of more fumes. Has this has any effect in reduction of LO tank vacuum?

Kindly clarify

 

@sudharson1007,

There are many types of L.O. mist eliminators used on GE-design Frame 5 heavy duty gas turbines; the turbines have been produced for 70+ years, and during this time the technology has changed a great deal.

You are correct in that L.O. temperatures increase with increased load. BUT, most bearing enclosures are slightly pressurized by the Cooling and Sealing Air System, primarily through small orifices (or is it orifi???). The Cooling and Sealing Air System gets its supply from axial compressor discharge--which increases with load. This pressure also makes it way to the L.O. tank through the L.O. drain system. So, it's not just increased heat and vapors that cause the vacuum to reduce and the pressure in the L.O. tank to rise, it's also the Cooling and Sealing Air pressure from the bearing enclosures.

Typically, most L.O. Mist Eliminators do not have any kind of automatic control mechanism which monitors L.O. tank vacuum/pressure and makes adjustments to maintain a desired level of pressure/vacuum. If the machine you working in [sic] has a manually adjustable butterfly valve to set the L.O. tank vacuum/pressure at some particular load (usually specified on a NOTE on the L.O. System P&ID) that setting doesn't change with load as does bearing heat and axial compressor discharge pressure.

Get your own copy of the P&IDs for the machine you are working on. Study them and get very familiar with each of the systems and components--many of which ARE NOT controlled or even monitored by the turbine control system, by the way (like many L.O. Mist Eliminator control valves). Take the time to try to visually find all the devices (the ones inside the L.O. tank are very difficult to see visually, but there are drawings in the Parts List section of the Operation & Maintenance Manuals provided with the machine which you can use to find their location. Make notes on your copies of the P&IDs--include the settings of devices (pressure switches; temperature switches; pressure transmitters; etc.). Read EVERY NOTE on the P&IDs. This will all make you the best operator and/or technician at your site. This is truly the best way to learn and understand how a GE-design heavy duty gas turbine--and its auxiliaries--work and are controlled and protected.

 

@sudharson1007,

There are many types of L.O. mist eliminators used on GE-design Frame 5 heavy duty gas turbines; the turbines have been produced for 70+ years, and during this time the technology has changed a great deal.

You are correct in that L.O. temperatures increase with increased load. BUT, most bearing enclosures are slightly pressurized by the Cooling and Sealing Air System, primarily through small orifices (or is it orifi???). The Cooling and Sealing Air System gets its supply from axial compressor discharge--which increases with load. This pressure also makes it way to the L.O. tank through the L.O. drain system. So, it's not just increased heat and vapors that cause the vacuum to reduce and the pressure in the L.O. tank to rise, it's also the Cooling and Sealing Air pressure from the bearing enclosures.

Typically, most L.O. Mist Eliminators do not have any kind of automatic control mechanism which monitors L.O. tank vacuum/pressure and makes adjustments to maintain a desired level of pressure/vacuum. If the machine you working in [sic] has a manually adjustable butterfly valve to set the L.O. tank vacuum/pressure at some particular load (usually specified on a NOTE on the L.O. System P&ID) that setting doesn't change with load as does bearing heat and axial compressor discharge pressure.

Get your own copy of the P&IDs for the machine you are working on. Study them and get very familiar with each of the systems and components--many of which ARE NOT controlled or even monitored by the turbine control system, by the way (like many L.O. Mist Eliminator control valves). Take the time to try to visually find all the devices (the ones inside the L.O. tank are very difficult to see visually, but there are drawings in the Parts List section of the Operation & Maintenance Manuals provided with the machine which you can use to find their location. Make notes on your copies of the P&IDs--include the settings of devices (pressure switches; temperature switches; pressure transmitters; etc.). Read EVERY NOTE on the P&IDs. This will all make you the best operator and/or technician at your site. This is truly the best way to learn and understand how a GE-design heavy duty gas turbine--and its auxiliaries--work and are controlled and protected.

@sudharson1007,

There are many types of L.O. mist eliminators used on GE-design Frame 5 heavy duty gas turbines; the turbines have been produced for 70+ years, and during this time the technology has changed a great deal.

You are correct in that L.O. temperatures increase with increased load. BUT, most bearing enclosures are slightly pressurized by the Cooling and Sealing Air System, primarily through small orifices (or is it orifi???). The Cooling and Sealing Air System gets its supply from axial compressor discharge--which increases with load. This pressure also makes it way to the L.O. tank through the L.O. drain system. So, it's not just increased heat and vapors that cause the vacuum to reduce and the pressure in the L.O. tank to rise, it's also the Cooling and Sealing Air pressure from the bearing enclosures.

Typically, most L.O. Mist Eliminators do not have any kind of automatic control mechanism which monitors L.O. tank vacuum/pressure and makes adjustments to maintain a desired level of pressure/vacuum. If the machine you working in [sic] has a manually adjustable butterfly valve to set the L.O. tank vacuum/pressure at some particular load (usually specified on a NOTE on the L.O. System P&ID) that setting doesn't change with load as does bearing heat and axial compressor discharge pressure.

Get your own copy of the P&IDs for the machine you are working on. Study them and get very familiar with each of the systems and components--many of which ARE NOT controlled or even monitored by the turbine control system, by the way (like many L.O. Mist Eliminator control valves). Take the time to try to visually find all the devices (the ones inside the L.O. tank are very difficult to see visually, but there are drawings in the Parts List section of the Operation & Maintenance Manuals provided with the machine which you can use to find their location. Make notes on your copies of the P&IDs--include the settings of devices (pressure switches; temperature switches; pressure transmitters; etc.). Read EVERY NOTE on the P&IDs. This will all make you the best operator and/or technician at your site. This is truly the best way to learn and understand how a GE-design heavy duty gas turbine--and its auxiliaries--work and are controlled and protected.

Thank you so much for your detailed explanation.