G.E. Part Number for Instruments on frame VI gas turbine system

Please I need G.E. part number for the following instruments used on General Electric frame VI gas turbine system
1. Compressor Inlet Pressure drop transmitter (96CS)
2. Hydraulic ratchet system limit switch (33HR)
3. Starting Clutch limit switch (33CS)

Then I would also need assistance for the G.E. part No for the following electric pump motors
1. Auxilliary lube oil pump motor (88QA)
2 88VG
3 88 BT
 
sirdee90,

Do you not have access to the Parts List/Manual provided with the turbine-generator and auxiliaries when they were new? To be sure you receive P/Ns for machine as much like yours as possible, you would need to tell us the age of the unit (when it was installed when it was new).

The three devices you mentioned are nothing special--meaning the equivalent is available from many different manufacturers. The compressor inlet static pressure transmitter is a 4-20 mA differential pressure transmitter, usually a two-wire transmitter, that is commonly available from just about any manufacturer. You just need to provide your preferred instrument vendor with the required range (listed in the Device Summary, or available from the I/O Configurator or Toobox/ToolboxST input configuration screens).

You could also see if there is any identifying information from the transmitter manufacturer on the transmitter or the inside of one of the removable covers that you could show to or provide to your preferred instrument vendor. Fisher-Rosemount or Yokogawa or Emerson or Fuchs-Pepperel--any 4-20 mA transmitter manufacturer--should make a suitable equivalent. (The difference will probably be in the pressure connection locations and types, and a good instrument tech with an assortment of tubing fittings should be more than capable of resolving this little problem).

The hydraulic ratchet limit switch was typically a third-party switch that is bolted (or screwed) to the hydraulic ratchet self-sequencer. Historically, the self-sequencer was manufactured by Young & Franklin in the USA, and the switch was a spring-load switch that is actuated by a small plunger that extends out from the self-sequencer when the ratchet reaches the end of a forward stroke. (The plunger is small and has a short "throw" meaning it doesn't extend very far from the self-sequencer when pressure forces it out to press the switch mechanism to get it to change state.) The switch needs to have contacts rated for 125 VDC (very low current--on the order of micro-amperes), and have a Normally Open (NO) set of contacts that will be closed when actuated by the plunger of the self-sequencer. If you have a good instrument vendor you could show the switch to the representative and they should be able to find a suitable replacement.

The starting clutch limit switch is also an off-the-shelf switch; there is nothing special about it. Again, you should be able to show the switch to an instrument vendor and they should be able to find one that will be a very suitable replacement. Again, the switch contacts need to be rated for 125 VDC, micro-amperes of current.

Both of the limit switches usually used a Micro-switch (that's the manufacturer's name) inside the switch housing, which was usually manufactured by another company. Unless someone painted over the nameplate on the outside of the switch housing, you should be able to retrieve the manufacturer's name and part number.

As for the pump motors, you should be able to get information from the motor nameplate that you can give to your preferred electric motor shop/vendor and they should be able to get a very cost-effective replacement. These are just AC motors; nothing special with them, either. The motors are usually rated for high-temperature service and may be totally enclosed (so explosion-proof--which should be available from the motor nameplate.)

Hope this helps! I know finding part numbers in manuals can be difficult, but if you will sit down with no other interruptions for a couple of hours or so and page through the Parts List/Manual, and have a pad of Post-It notes handy (or similar colored notes with sticky backs) you will be absolutely amazed at how much you will see is available--things you want to be able to get back to quickly some other time. You will probably find the information you are looking for, but, unfortunately there's no searchable Index and the organization (if one can call it that) usually leaves something to be desired. THOUGH, once you do page through it from beginning to end, and if you do that more than once, you WILL begin to see that it is "organized."

One used to be able to "call GE" and tell them the serial number of their turbine and describe the part they wanted and GE would locate it in their database and provide it (for a very "nominal" price!!!). No more, though I am told there are some vendors who still have people who can do this they are becoming more and more difficult to find.

Please write back to let us know how you fare!
 
sirdee90,

Do you not have access to the Parts List/Manual provided with the turbine-generator and auxiliaries when they were new? To be sure you receive P/Ns for machine as much like yours as possible, you would need to tell us the age of the unit (when it was installed when it was new).

The three devices you mentioned are nothing special--meaning the equivalent is available from many different manufacturers. The compressor inlet static pressure transmitter is a 4-20 mA differential pressure transmitter, usually a two-wire transmitter, that is commonly available from just about any manufacturer. You just need to provide your preferred instrument vendor with the required range (listed in the Device Summary, or available from the I/O Configurator or Toobox/ToolboxST input configuration screens).

You could also see if there is any identifying information from the transmitter manufacturer on the transmitter or the inside of one of the removable covers that you could show to or provide to your preferred instrument vendor. Fisher-Rosemount or Yokogawa or Emerson or Fuchs-Pepperel--any 4-20 mA transmitter manufacturer--should make a suitable equivalent. (The difference will probably be in the pressure connection locations and types, and a good instrument tech with an assortment of tubing fittings should be more than capable of resolving this little problem.

The hydraulic ratchet limit switch was typically a third-part switch that is bolted (or screwed) two the hydraulic ratchet self-sequencer. Historically, the self-sequencer was manufactured by Young & Franklin in the USA, and the switch was a spring-load switch that is actuated by a small plunger that extends out from the self-sequencer when the ratchet reaches the end of a forward stroke. (The plunger is small and has a short "throw" meaning it doesn't extend very far from the self-sequencer when pressure forces it out to press the switch mechanism to get it to change state.) The switch needs to have contacts rated for 125 VDC (very low current--on the order of micro-amperes), and have a Normally Open (NO) set of contacts that will be closed when actuated by the plunger of the self-sequencer. If you have a good instrument vendor you could show the switch to the representative and they should be able to find a suitable replacement.

The starting clutch limit switch is also an off-the-shelf switch; there is nothing special about it. Again, you should be able to show the switch to an instrument vendor and they should be able to find one that will be a very suitable replacement. Again, the switch contacts need to be rated for 125 VDC, micro-amperes of current.

Both of the limit switches usually used a Micro-switch (that's the manufacturer's name) inside the switch housing, which was usually manufactured by another company. Unless someone painted over the nameplate on the outside of the switch housing, you should be able to retrieve the manufacturer's name and part number.

As for the pump motors, you should be able to get information from the motor nameplate that you can give to your preferred electric motor shop/vendor and they should be able to get a very cost-effective replacement. These are just AC motors; nothing special with them, either. The motors are usually rated for high-temperature service and may be totally enclosed (so explosion-proof--which should be available from the motor nameplate.)

Hope this helps! I know finding part numbers in manuals can be difficult, but if you will sit down with no other interruptions for a couple of hours or so and page through the Parts List/Manual, and have a pad of Post-It notes handy (or similar colored notes with sticky backs) you will be absolutely amazed at how much you will see is available--things you want to be able to get back to quickly some other time. You will probably find the information you are looking for, but, unfortunately there's no searchable Index and the organization (if one can call it that) usually leaves something to be desired. THOUGH, once you do page through it from beginning to end, and if you do that more than once, you WILL begin to see that it is "organized."

One used to be able to "call GE" and tell them the serial number of their turbine and describe the part they wanted and GE would locate it in their database and provide it (for a very "nominal" price!!!). No more, though I am told there are some vendors who still have people who can do this they are becoming more and more difficult to find.

Please write back to let us know how you fare!
 
Thanks a lot , all the units (GTs) are old and the name plate on the instruments are either fell off or rusty, all your advice will be strictly adhered to. Thanks a lot
 
sirdee90,

It's just my opinion that if you had GE part numbers and you tried to order/buy these parts from GE they would be VERY expensive--compared to trying to work with local suppliers to find what are really pretty common-place controls devices. If you don't already have a preferred supplier of control equipment, you may find it easier (though more expensive) to buy from "GE."

Now, someone may have these part numbers relatively handy and could post them to a reply to this thread. Or, someone may have an older Parts List/Manual and have the time to look them up. (It would actually probably be easier to find them in an older manual because lots of newer units had compartments and options which were purchased from vendors who didn't always provide part numbers or parts list for the equipment--and most of them did not have GE part numbers.)

Here's a little thing I do when I'm looking for a controls device--like a pressure switch or a limit switch or similar. For example, let's say I was looking for a L.O. header temperature switch, 26QA-1. I know at least three things about the device: 1) It's mounted on the outside of the Accessory Compartment, under the walkway on the left side of the unit. 2) The sensing bulb of the switch is in a thermowell on the L.O. Bearing piping downstream of the pumps and coolers and filters. 3) It is a switch--so it will have electrical conduit and wires attached to it.

Me--I'm going to go to the section of the Parts List/Manual that has all the conduit for all the compartments and systems in it and find the drawing for the Accessory Compartment that shows the outside of the left side of the Accessory compartment where three temperature switches are located (26QA-1, 26QT-1 & -2) and the L.O. Tank Level Switches (71QH-1 and 71QL-1). There may also be some other electrical devices on that side of the Acc. Compt. (like L.O. Tank Temperature T/Cs, and switch(es) for the L.O. Tank heater(s)). I'm going to look at that drawing and find the switch I'm looking for and get an item number, and then find the item number in the Parts List which should have the Part Number for the switch on the same line.

Sometimes, the electrical drawing only shows the conduit and fittings--BUT it has a reference to the ML (Model List) of another drawing and Parts List which has more information about the temperature switch. So, let's say it sends me to ML-917 (a pure guess!); I go to the 0900 section of the Manual and find the drawing for ML-917 (the ML numbers are always shown in the lower right-hand corner of the drawings), and scour the drawing until I find the Item number, then go to the Parts List and find the Part Number of the Switch.

Sometimes, I work the other way. I go to the piping section of the manual (cause I know the sensing bulb of the 26QA-1 is in the L.O. Bearing header) and find the piping drawing for the L.O. bearing header in the Accessory Compartment and find the switch Part Number on the Parts List for that piping drawing, or it sends me to the Electrical drawing where I find the switch Part Number on the Parts List for that electrical drawing.

But, in any case, I use the information I have about the location of the device I'm looking for, and then I go searching the relevant drawings (in this case, the piping drawing and/or the electrical drawing for the area/system where the device is located).

Sometimes, if the device I'm looking for is part of the generator, it's a little more difficult.

In the case of the pressure transmitter you are looking for, it might be difficult to find either and electrical or tubing drawing for the system to find the switch. In that case, since you know it's a 4-20 mA transmitter, and you know what the required scaling is for the application (from the Device Summary, or from you plant's Calibration Data Sheet for the device-which may ALSO list the manufacturer and the manufacturer's Part Number!) you can talk to an instrument supplier and tell them what you need and they can recommend a suitable replacement (that may need some tubing and/or conduit changes to accomodate on the unit since it likely won't be exactly the same shape and configuration if it's not from the same manufacturer).

But, nothing here is insurmountable. Going through the Parts Lists/Manuals when you are pressed for time and have never had to look through them before is very close to impossible to find precisely what you're looking for. Again, it doesn't seem to be organized at first look. BUT, if you'll take the time (and you SHOULD take the time if you're going to working on these units for any length of time) to go somewhere free of interruptions and distractions and start paging through the manual--you will be amazed at what you find. And, when you do go back to the manual later to look at things you found, remember to always look at the NOTES section of the drawing--where you will usually find some very interesting information!

Best of luck--hope this helps! It's not impossible to find things in the manuals, but it is hard--at first. Or maybe even the second or third times. Admittedly, there will be a time or three you will NOT find what you are looking for--either because it's NOT in there, or it's really buried and hidden. (GE, and it's packagers, were never really good about making sure every part number and every relevant drawing was in the Parts List/Manual. Unfortunately.) But, familiarizing yourself with the Parts List/Manual is never a bad thing. Never.
 
Electronic differential pressure transmitters are commodity items nowadays (really old pneumatic output DP's are not, they are obsolete) - there's a dozen major league players that produce excellent, reliable products. Their origins were for flow measurements across orifice plates in the 1920's. The typical orifice plate installation lead to the adoption of a near world-wide convention for process connection dimensions - 1/4 NPTF threaded ports on 2 1/8" or 54mm centers, as shown in the diagram below. So connection to a new DP is likely to be exactly the same as the old one, dependent on the mounting of the transmitter.

STD700 process connections on 2.13 inches (54mm) centers 2 - hi.jpg

Older electronic DP transmitters tended to have larger housings and pressure elements; current model are likely to be smaller so they'll fit into the space but might require some attention to mounting if the old mounting bracket does not hold the new transmitter securely. Creative mechanics can usually come up with a solution.

If the process needs vents on the transmitter's process heads to either vent gas from liquid medium or to drain liquid or condensate from gas medium then be sure to get vents, which are always optional. (Process heads are dead-headed and the vents allow for temporary purging)

Older analog electronic DP's were almost always installed with a 3 or 5 valve manifold in flow applications (and most other applications as well) in order to isolate the transmitter for calibration and to provide valving to calibrate the zero on a fairly frequent basis. Power plants in this area used to calibrate every 6 months and in the analog electronic era, those transmitters needed frequent re-calibration. Modern 'smart' transmitters have negligible drift, but the convention of using a 3 valve manifold for isolation is still prevalent. If the installation in question has had numerous calibrations over the years it might pay to replace the valve manifold, too, because the valve seats can be damaged by overtightening.

Like CSA says, you do need to know the DP pressure range that it needs to measure.
 
To add to David_2's excellent posting, it's possible that because of the age of the machines the transmitters might have been three-wire or four-wire transmitters.... early Mark IV-era turbine control panels didn't have two-wire 4-20 mA inputs; later ones did. Mark II-era turbine control systems could only accept VDC inputs (which can easily be handled with the addition of a dropping resistor--BUT, in some cases GE actually sourced and provided four-wire transmitters which used a differential voltage input (+12 VDC and -12 VDC for power; and two wires for the 0-5 VDC output or 0-10 VDC output).

In any case, the calibration data sheets you have been using for calibration verifications of the transmitter should have the information you are looking for, possibly even the manufacturer's name and model number...??? Or, the Device Summary provided with the turbine-generator and accessories in the Operations & Maintenance Manuals should at least have the range information.

So, my apologies for not remembering the older, earlier types of transmitters GE provided. Not knowing what kind of control systems are in use on the units kind of hampers our responses. And, if they are not GE Mark* turbine control systems, then the Instrument Technicians responsible for troubleshooting and maintaining the turbine control systems should be capable of determining the input type (mA or VDC) and if there is an added dropping resistor or not, and what the scale/range of the input is.

Hope this helps!!! And sorry for any confusion. (Thanks David_2 for jogging this old memory!)
 
GAS LEAKAGE IN GAS VALVE (SRV)OF FRAME VI GAS TURBINE SYSTEM.

Good day to you all, please I need comprehensive information about the possible cause of gas leakage from the valve of SRV, whenever the main gas valve is opened during the preparation to run the unit. Because it happens to one of our UNIT whenever the unit is about run up, Pressure gauge P2 (intermediate) in the gas chamber will register the presence of pressure and sound of gas escaping through 20VG is noticed
 
BUT, in some cases GE actually sourced and provided four-wire transmitters which used a differential voltage input (+12 VDC and -12 VDC for power; and two wires for the 0-5 VDC output or 0-10 VDC output).
Thanks for the very interesting historical note - the bipolar ±12VDC power supply for a 4-wire pressure transmitter. That precedes my experience. I just assumed two wire, loop power for an industrial pressure transmitter because that's been my experience and it just goes to show - assumptions will always get you.
 
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