Hello everyone,

After a thorough inspection of the MS3132, we identified several issues:

- Malfunctions in the oil pump
- Auxiliary 88QA issues
- Auxiliary hydraulic 88QH problems
- BSML compressor seal pump issues (models 88SP1/88SP2)
- Lubrication oil collector pressure at 1.2 bar (nominal pressure is 1.75 bar)
- Gas/oil seal pressure at 0.75 bar BSML compressor seal
- Auxiliary pump operates even when the mechanics are in use
- The second BSML compressor seal pump is also activating
- Low oil level in the BSML compressor oil tank, used during shutdown.

Thank you for your assistance with these matters.

 

@med2025,

What is a BSML?

Who was the packager of the MS3132? (There are multiple companies that package GE-design heavy duty gas turbines under license from GE--BHEL is one, for example.)

How old is this machine?

What kind of control system does it have?

WHEN did these problems start? Immediately after the maintenance outage?

First, these problems almost ALL seem to be mechanical issues (oil pumps; pressure regulators; oil levels)--ALL things that the MS3132 turbine control system most probably does not actively control. This is a controls-related forum. Yes; often we help with mechanical issues but without more information about your machine and its auxiliaries and control system we can't offer much help or support.

To me, it seems that the problems are mostly related to the lubricating oil system (lubricating oil is usually the fluid for the hydraulic system and the seal oil system of many GE-design heavy duty gas turbines driving compressors). Generally, under normal conditions the Main L.O. Pump, which is located in the Accessory Gear Box, supplies the oil to the suction of the main- and auxiliary hydraulic oil pumps and possible to the seal oil pumps as well (not always, but on some machines which use lubricating oil for the (centrifugal?) compressor seal oil system). Insufficient oil pressure/flow from the main lubricating oil pump can therefore affect many other devices (pumps) and systems (hydraulic and seal oil). But, a GE-design machine with a GE Mark* turbine control system doesn't usually control lubricating oil pressure or hydraulic oil pressure or seal oil pressure--it just monitors and reports (alarms) problems with the pressures of these systems and can trip the machine on excessively low pressures.

Please write back to let us know what you find. If you need further assistance, you will need to provide more--much more--information. But, again, as the problem(s) appear to be mostly mechanical in nature it's doubtful that we can be of a lot of help.

 

@med2024,

You wrote about malfunctions of the oil pump. Typically, accessory gear-driven Main L.O. pumps (I'm presuming you meant the Main L.O. pump...) are positive displacement pumps that use a relief valve to regulate the Main L.O. pump discharge pressure. After that, the bearing L.O. header pressure is regulated by a diaphragm-type pressure regulator (it is typically a modified pressure regulator that has a small hole drilled in the valve plug so that it can never fully block the flow of oil--to protect the bearings as long as the coupling between the pump and the accessory gear box drive is not broken).

You did not say what the details of the malfunction of the oil pump, which would have helped with responses.

The Aux. L.O. pumps of GE-design heavy duty gas turbines usually have a valve (often called a "foot valve") in the suction of the pump to keep the pump suction "flooded" (full of oil) after the pump has stopped running. This tries to ensure that the pump will VERY QUICKLY start flowing oil when started--such as in the event of a failure of the Main L.O. pump.

GE-design heavy duty gas turbine generally have a dual main L.O. filter system with a transfer valve which can be adjusted while the machine is running to change from one filter vessel to the other filter vessel. Since most of the pumps on a typical GE-design heavy duty gas turbine machine (including compressor seal oil pumps--unless the medium the compressor is compressing is some kind of safety hazard (human or fire)) have their suctions fed by the regulated bearing header pressure line if there is some kind of problem with either the bearing header pressure regulator and/or the Main L.O. filter transfer valve that could be affecting both the Aux. Hyd. and Seal Oil pumps at the same time. But since we don't know what problems any of these pumps are experiencing (low pressure or low flow) we can't offer any suggestions--other than what we have offered.

Again, regulated bearing header pressure is usually applied to the suction of the Main (accessory gear-driven) and Auxiliary Hydraulic Oil pumps. This is because the hydraulic oil pumps are usually axial vane type positive displacement pumps and aren't really capable of drawing a suction from the L.O. tank/reservoir, and it also ensures the pumps have oil to lubricate them and will start producing hydraulic oil flow and pressure quickly when started (the Main. Hyd. Oil pump is coupled to the accessory gear usually with a nylon coupling.

Both hydraulic pumps have internal, manually-adjustable pressure/flow compensating mechanisms which are used to set the discharge pressures of the pumps. Both pumps have manually-adjustable over-pressure relief valves--which MANY people mistakenly use to set the hydraulic oil pump discharge pressures. Using the hydraulic pump over-pressure relief valves to set the hydraulic pump discharge pressure results in excessive flow through the hydraulic pumps--and often causes the Aux. Hyd. Oil pump to alarm on overcurrent (because the extra flow is causing the pump motor to draw excessive current). In other words, there should be zero flow out of either hydraulic oil pump relief valve under normal operating conditions. To adjust each hydraulic over-pressure relief valve is it necessary to slowly increase the pump pressure/flow compensator setting until it slightly exceeds the specified pressure of the relief valve--at which point the relief valve should start relieving. If it doesn't that means that the relief valve pressure setting is adjusted too high and needs to be reduced just until the pressure relief valve starts allowing oil to flow through it; and then the relief valve jam nut needs to be tightened to maintain the setting. Finally, the pump pressure/flow compensator setting needs to be reduced to the specified pump discharge setting, at which time the pump's relief valve will stop flowing oil.

The hydraulic oil system of a typical GE-design heavy duty gas turbine is mostly a static system--the only time there is a "large" flow of oil through either pump is when some hydraulically-operated device is being commanded to move quickly, which is not typical under normal running or even start-up or shutdown conditions.

Again--many of us don't know what a BSML compressor is. We can surmise from your post that it is the abbreviation for the purpose of the compressor that is being driven by the gas turbine (MS 3132), but that's all many of us can know do. (The majority of GE-design heavy duty gas turbines are single-shaft machines and are used to drive synchronous electric generators, though a few single-shaft machines are used to drive centrifugal compressors or compressor trains. Most two-shaft GE-design heavy duty gas turbines are used to drive compressor or pumps of some sort, though a few are used to drive generators in unique applications (such as main propulsion engines for ships).)

You only wrote that the BSML compressor seal oil pumps have issues and we are guessing that the fluid for the compressor seal oil system is lubricating oil and have no ideas what the issues are. It seems to be that there is low flow and pressures in the systems. If so, the turbine control system would be alarming--and starting any standby/lag pump to try to augment the pressure. But, if the L.O. pump suctions are choked OR the bearing header pressure regulator is not functioning properly OR the Main L.O. filter transfer valve is not in the proper position (or the filter transfer valve is also not in the correct position--which, since it flows so little oil that's probably not a possible issue)--OR the Main L.O. filters are the incorrect filters or they are choked (dirty) or they weren't installed correctly could be the problem or part of the problem.

The GE heavy duty gas turbine control almost NEVERS controls things like L.O. pressure or flow, or Hydraulic Oil pressure or flow, or Seal Oil pressure or flow--these are almost ALWAYS controlled by "old fashioned" mechanical means that would be be unaffected on a complete failure of the turbine control system. The turbine control gets signals on low or low-low pressures (which could be because of low flows!) and annunciates alarms--which you didn't provide any information about.

So, it should be pretty clear that your issues are most likely NOT related to the turbine's control system--but that if there were issues with pressure (which can be caused by low flow--which might even be caused by a leak in the oil piping somewhere--most likely in the oil tank). The low flow issues could be caused by improper setting of the Bearing Header pressure regulator or problems with the pressure regulator, or by Main L.O. filter issues (transfer valve position or choked (dirty) filters, or improperly installed filters)--or a leak which isn't obvious because it's either in the oil tank/reservoir, OR in the bearing lines or Seal Oil pump lines (GE has a philosophy of putting oil feed (supply) lines INSIDE of oil return lines so that a leak in a feed (supply) line will not spill on the ground or floor--which makes such leaks difficult to find without disassembling the drain AND feed lines, which is not an impossible task because they were most assembled on site (with the possible exception of the turbine compartment oil return tank which is usually constructed at the factory)).

Anyway, this is all I can offer based on the information provided. Usually I ask for a lot of data and information, but lately it just seems to confuse people. So, I hope this helps--and it would be really nice of you to write back to let us know how these issues are resolved. Typical GE systems and philosophies are going through somewhat of a change so if you have a newer machine some of this may--or may not--apply. Use the L.O. System and Hydraulic Oil System P&IDs for details about the systems are interconnected. Since it seemed the BSML compressor is not GE then you will probably have to consult the P&IDs provided with that system. It sounds like there's a "run down" tank for the BSML compressor to but provide oil in the event there is no oil flow from the gas turbine's regulated bearing header--but without being able to see all the relevant P&IDs it's impossible to say for certain anything other than what experience has been and what GE's typical machine philosophies are.

Best of luck! We look forward to hearing how the issue(s) were resolved!!!

Tchau!

 

I corrected a few typographical errors and spelling errors and grammatical mistakes in the previous post.

I want to add one more point: If these problems started during the restart of a machine after a maintenance outage often similar problems have been caused by incorrect positioning of manual hand valves —including the “block-and-bleed” valves on the Accessory Gauge Cabinet where pressure gauges and pressure switches are located. If the pressure gauges and -switches were checked for proper operation (sometimes called “calibration”) during the maintenance outage it’s very possible the manual valves on the gauge cabinet were not set to the normal running positions after the work was completed and were not properly verified to be in the proper positions prior to the restart of the machine.

Anyway, that’s all I have on this thread.

Tchau!

 

@WTF?

Hello,

Thank you for providing this valuable information.

I need to report another issue: a fire has occurred on the exhaust line and the oil box breather, which is located next to the exhaust line and is responsible for venting oil vapours to the atmosphere and the Cooper Besmer seal gas (centrifugal compressor). The fire occurred while both the turbine and compressor were in operation.

I appreciate your assistance in resolving this matter, as well as your help in identifying the root causes of this incident.

Thank you.
Regards

 

@med2025,

This latest request for help with a oil demister problem should be its own thread.

AND, when you open a new thread you need to provide the manufacturer and model of the "oil breather."

All we can say now is that it's probably likely that there was some kind of oil drain problem or blockage that caused oil to flow into the exhaust and get ignited. This presumes the machine does NOT exhaust into a heat recovery steam generator. (Something else you should also provide in the new thread.)

You should also say when the fire occurred (when the machine was running or when it was starting; after a maintenance outage; after some problem with the "oil breather"; etc.).

You can attach photos to threads when posting to Control.com.

You should also know that EVERY GE MS3132 IS NOT like every other GE MS3132. They have changed over the years, and the turbine was packaged and sold by several licensees of GE's technology, almost always with auxiliaries that GE may not have provided or used. So, really--without a LOT more information there's probably very little that can be said. Without any more information I can't offer any more help or suggestions.