Aero-Derivative Industrial Gas Turbine and flight oils

[sub_zero]

Hey all,

Thought I'd give you all a chance to kick this can of worms too.

Well I was talking with the fleet manager of aero-derivative marine engines for the Canadian Navy this morning and the topic of lube oil came up.

BTW I manage the test facility for a large independant and worldwide overhauler of Industrial Aero-Derivative gas turbines manufactured by GE and Rolls-Royce, we have 6 engine lines.

Anyway we were discussing oil costs vs. performance and he mentioned what makes the oils so expensive, almost 9.00/L, are the additves for flight application, especially the anti-foaming agents. I wanted to get that verified here before I go off to BP etc. and demand an industrial specific oil, OEM apporved of course.

I have sought solutions to lower the cost of test, we lose a few gallons per test and it can be recovered, processed and reused. Those that I have spoken with regarding the service have very high pricing to get into this, right now. So I'd like a cheaper oil in the meantime. I've heard of a Castrol oil that may fit the bill, I've googled it but came up with nothing.

Anyone have an opinion?

 

[userfriendly]

I thought that BP Air sold out to Exxonmobil.
Try your Esso bulk plant for ETO 2197, if that is what you need.

 

[sub_zero]

I have been using BP Turbo Oil 2380 (the old exxon turbo oil 2380) with very good results. Air BP purchased the Exxon Aero lube business during the Mobil/Exxon merger.

2197 is the new High Thermal Stability Oil and a touch more dear than 2380. I just checked the book and all the approved oils are flight oils.

I may just have to bite the bullet and reclaim the oil.

 

[stillman]

I operate a GE LM5000 aero derivitive gas turbine. My guess is, the manufacturer will instruct you to use an OEM approved lubricant, which will most likely be a flight engine oil. I wasn't aware that the flight approved oils had special anti-foaming additive. But it doesn't surprise me, because I know the individual sump cavities on flight engines and their land and marine derivatives are pressurized with air from the HPC.

We have used MobilJet II synthetic gas turbine engine oil exclusivly for 13 years. No oil related failures, just plenty of failures! (We have a full STIG unit. 70,000 shp/50 MW.)

Castrol does make a synthetic gas turbine lubricant that is approved by GE. I've had no first hand experience with it, but can relate this interesting story: Several years ago I attended a GE gas turbine user's conference. In one of the individual conference's, the subject of lube oil came up and we did an informal survey on lube oil brand. The facilitator asked who used Mobil lubricant. All but one hand went up. The facilitator then asked who used Castrol. One hand. The question was then asked who has experienced coking problems with their oil, or had bearing failures related to coking. Only one hand, the Castrol guy.

Now I don't mean to endorse one brand over the other. It was clearly not a scientific survey. But among the user's it carried a great deal of meaning, because sharing similar problems, experiences, solutions and trying to build trends on the entire engine fleet was the whole point of the conference.

[ October 21, 2003, 01:53 AM: Message edited by: stillman ]

 

[Jelly]

Take a look at the Mobil line:

Jet Oil II
Jet Oil 254
Jet Oil 291

 

[sub_zero]

stillman,

Some customers have requested Mobil Jet II be used for testing. I've declined the request since Mobil uses tricresyl phosphate (TCP) in the add pack and is not as benign as the BP product. Since the boys are exposed quite often to the oil the TCP could pose a health hazard down the road....

As for Castrol jet oil, I haven't seen it for a few years now, was used quite a bit in the Rolls-Royce engines though.

The anti-foaming agents for flight oil are the deluxe model since the oil is moving from a pressurized sump to an atmosphere at 30,000 ft, and the tanks are small. The oil is well aereated when scavenged and that air at high pressure will expand rapidly when returned to the tank, which is at ambient pressure, only a few psi at altitude. The frothy mess in a small tank (5 gallons for a 50,000lbs thrust machine) that would result without high performance anti-foaming would cavitate pumps and hamper effective cooling, not to mention the oil pressure

This of coarse isn't the case with an industrial unit on the ground with a big tank.

I've never worked on the LM5000 but I have worked on the LM6000 a bit. The LM6000 is a Nancy boy's engine

since the STIG LM5000 will produce more power than a LM6000 PC /w Enhanced Sprint. Gives you good bragging rights even though it may be prone to the occasional chucked blade

Jelly,

The Mobil stuff is good oil especially the 254 and 291 High Thermal Stability oils. They prevent coking which can be a problem especially on light turboshafts. These oils even allow on some engine models a Time Before Overhaul (TBO) extension from the OEM with there use, they are that good! Operators love that kind of stuff

 

[Cujet]

Another non scientific note:

(I prefer 2380 in all my aircraft due to performance and availability issues)

A small local fleet of Bell copters run on MJII had constant problems with gears wearing beyond limits and coked internals. No failures occured, however the money spent at overhaul time was significant.

Contrast that with my fleet of 8 aircraft run on 2380 since day one. We have never experienced any of the problems they did, even though we operate in the same manner, same engines and same mission profile.

I also have experience with the better Mobil products. They are fantastic. However the dark color really stains the white paint. Especially if the paint is the new high solids type.

Chris

 

[stillman]

sub_zero, yes, the TCP's concern me too. A few years ago I started wearing 4 ml nitrile gloves during our engine change-outs, or any time where I would come in contact with the lube. The key to comfort and keeping them from tearing is selecting the next size larger than you would normally wear. I've grown pretty acoustomed to them and I always used to hate wearing gloves while working on engines.

We will probably see more LM6000's in the future. There were only 102 LM5000's made. Some have been turned into part's engines. There are rotable spares in inventory, hot sections, compressor element's etc, but the spare turbine mid-frame is I think the rarity. Fortunately, GE maintains a good lease pool. I saw a 6000 at the Cincinatti facility and the modularized engine controls looked a lot better than the ones for the 5000 which has them dangling all over the package!

The 5000 earns it's bread and butter, but it will never be the reliable workhorse that I hear the LM2500 is.

 

[sub_zero]

I found it and it's not a Castrol product. From Petro-Canada called AJT 5200. Spec says it can be used where MIL-L-23699 is specified for industrial use. I know an LM6000 operator who is using it in two units right now. It is a few dollars cheaper than the BPTO 2380.

The LM2500 is a good engine and a real workhorse. I see alot of them, mainly power gen. but a few mechanical drive. The Rolls-Royce Avon is a heck of a good engine too. Burns alot of gas though.

 

[userfriendly]

Would Pet-Can's endurance 8000 work in your application? Its likely cheaper than the AJTs.

 

[sub_zero]

Doesn't look like Endurnace 8000 makes the grade. The tech sheet gives an operating temperature of 95deg C, my application has the scavenge oil returning at 150deg C or so. The resistance to oxidation has to be excellent in this appplication.
In one application the lube sytem is turned off within seconds of shutdown. The unit rolls to a stop with no lube flow but with all the heat left in the machine, any residual oil will turn to coal if it can't take the heat = well over 200deg C.

Some engines inject air to the turbine bearing sump during shutdown to prevent coking.

 

[userfriendly]

I think the book implies 8,000 hours service at 95C, not that 95C is the temperature ceiling of the fluid.
The stuff is still $9.00/litre.
Esso has some ester compressor fluids that might do, I would imagine the cost to be about $2,000.00+ per drum.
Imperial oil Edmonton: 403-440-8100
Tech services English 1-800-268-3183

 

[userfriendly]

Shell has gas turbine oils as well, see their products on the CDN web site.
I'm sure I saw a Shell tanker truck the last time I was at the Calgary air port, so they must have a local dealer.

 

[68redlines73]

Some choices for you:

BP Turbo Oil 2380
Castrol Aero 5000
Chevron Synthetic Turbine Oil SGT
Mobil Jet Oil II
Shell AeroShell Turbine Oil 500
Texaco Regal SGT 22

 

[userfriendly]

Some back and forth a few months ago on JTOs.

The above thread implies that skin contact may be hazardous to your health.

Can anyone explain, and do JTOs still have a no contact rule?

 

[Tom NJ]

Not a few months ago - this thread is 12 years old!

All aero derived jet turbine engine oils meeting MIL-PRF-23699 and/or AS5780B are based on polyol esters (POEs) at 93 to 96%. This is the cause of the high cost. The anti-foam agent is a silicone oil dispersion at less than 10 ppm and has no impact on the cost.

All of these oils contain TCP at 2-3% and is not an issue. In the past some grades of TCP contained too much of the ortho-isomer, which is a potent neurotoxin. Today the TCPs have less than 0.1% of the ortho-isomer and are not considered a health hazardous at the dosage in turbine oils. That said, you should not drink them and should avoid skin contact or wash after handling, as with all lubricants.

The other additives are mainly anti-oxidants (at least two to exploit chemical synergies), and corrosion inhibitors. All of the oils contain yellow metal inhibitors and some have rust inhibitors. The anti-oxidants total 2-3% and the corrosion inhibitors usually total less than 0.5%.

Mobil Jet II and Eastman Turbo Oil 2380 are the oldest (Type II) turbine oils dating back to the early 60s. These oils are based on different POEs but have similar additives. Both work well in most engines, but some modern engines can stress Type II oils to a point where coking becomes a problem.

Today the latest turbine oils are considered 4th generation and include Eastman Turbo Oil 2197, Mobil Jet Oil 387, and Shell Ascender. These oils offer substantially improved coking performance in hot engines. The Eastman and Shell products are based on advanced POEs with enhanced oxidative stability, and all contain improved anti-oxidant chemistry.

Tom NJ