Dear Bob and AMMRL,
We’re looking at two Sumitomo F-50 helium compressors presently at ~60k hrs of operation. We replaced oil adsorbers, but nothing else.
Sumitomo has an exchange program for the compressor ($4500) but this also requires a “capsule” replacement for $3250 (all USD).
Apparently the oil adsorber, and the capsule both have a 30k hour expected lifetime, and then the compressor refurbishment is also recommended at 30k hours but this refurbishment is not as hard a number, but it seems like it’s encouraged to just do everything at the same time.
Basically Sumitomo has a 30k hours (~3.5years) recommendation. Have others found this?
This is a bit intimidating, given that every 10k hours (~1.1 years) we also have to do the cold-head ($6500 exchange).
Are other people finding this or just running their compressors until they die? Compressor death seems to mean system death?
I’ve never heard anything from the OEMs regarding compressor lifetimes for cold probes, hence my question(s).
best wishes,
Ryan
---------------------------------------------------------------------------------
Ryan T. McKay, Ph.D.
NMR Facility Supervisor
Room E3-17A Email: ryan.mckay_at_ualberta.ca <mailto:ryan_at_nanuc.ca>
Department of Chemistry Phone: 780.492.9950
University of Alberta Cell: 780.920.8871
Edmonton, Alberta
Canada T6G 2G2
Website: uab.ca/nmr
> On Jan 21, 2016, at 8:16 AM, Bob Berno <bberno_at_mcmaster.ca> wrote:
>
> Hello everyone,
>
> Thanks to everyone who took the time to respond.
> I received several responses, and as promised here is a summary.
> I'll include the redacted emails below, but I'll try my best to compile and distill the responses here.
>
>> How long has your helium compressor been operational?
>> Have you suffered a helium compressor breakdown?
> There is significant variation in how long the He compressor can run before breaking down. Certainly, it appears that my cryorobe with >92,000 hours of operation is at the upper end. There were at least two reports of helium compressors that exceeded the 100,000 hour milestone. One has already exceeded 110,000 hours!
> Many compressors fail in the 50,000 to 70,000 hour range. For the most part those that fail in much fewer operational hours could be traced to specific causes such as a manufacturing defect or most often, high oil temperatures.
> Clearly, effective heat dissipation is critically important to the short term and long term performance of these cryoprobe systems.
> This point has me more concerned about my "newer" cryoprobe with 50,000 hours and a history of poor chilled water supply.
>>
>> And are there any telltale signs that the failure is imminent?
> From an NMR spectroscopy perspective, it seems that there is little to no sign of an impending compressor failure. The probe and spectrometer seem largely unaffected until the compressor fails, which is catastrophic.
> There were a few very useful responses the explained the leading cause of compressor failure. Helium compressors most often fail when the oil overheats, degrades, overwhelms the absorber and then contaminates the helium line.
>
>> How expensive is it to repair/replace?
>>>
>>> Do you have a cryoprobe (or overall spectrometer) service contract where the helium compressor is covered?
>>> What is the approximate annual rate for such a service contract?
> Several of you mentioned that you had a service contract that included the helium compressor. For those of you who do not have service contracts, most of you indicated that the cost for a refurbished helium compressor was approximately $20k. If you are not afraid to get in and repair the system yourself, it is possible to order parts for quite a bit less money.
>
> Below you will find the verbatim responses I received. There are some excellent and detailed information contained, so if you have a cryoprobe system, please read on.
>
> --------------------------------------- emails below ----------------------------------------------
>
>> That does seem like a lot of hours.
>> We had several helium compressors break way before that, 35k hours, 56k hours, but have a newer one now with >65k hours. So I’m not sure the hours are predictable, neither was the time of failure in any of these cases. We had quotes from Bruker of $20k for a rebuilt and $40k for a new one several years ago, so we opted for the rebuilt one. Fortunately, we replaced the system before that one got up past 50k hours, hence I do not know whether a new or rebuilt one would be better. It lasted about as long or longer as some of the new ones did.
>> There is a third party, Cool Pair Plus. I contact them about the repair or exchange of a unit. They responded promptly, had some reasonable prices and over the phone made a good impression. Their repair seems to start at $3,250 or an exchange would be $5,000. I have not used them yet, but certainly would consider it at the next breakdown.
>
>> We have had to replace our outdoor helium compressor twice since 2007 .Since we had only one cryoprobe system we were able to keep it on contract with Bruker and they replaced them as part of the contract. My guess is the Bruker engineer was correct on the lifetimes. We are currently paying $19.500 /yr for cryoplatform and compressor contract and $7,600 for DulCH 5mm cryoprobe contract.
>
>> I had a air cooled helium compressor that ran 72,000 hours. These was no real warning for the failure. I had a service and maintenance contract on it, so Bruker replaced it without charge!
>>
>
>> I have a Cryomech L60 helium compressor that runs for our N2 plant. We got about 12000 hrs before the He compressor locked up. I think you need to be careful on the compressor oil temp…keep it right at spec which for this one is 100F
>
>> We had a helium compressor ran about 10 years without trouble. The Bruker replaced one for us due to a complicated story after our room remodeling without charge since we have service contract. If you have cryoplatform service contract, the compressor should be covered.The cryoprobe service contract can be purchased separately from the cryoplatform cervice contract. The helium compressor is covered under cryoplatform service contract.
>> Based on our experience, the cryoprobe is usually pretty reliable, and it is not necessary to buy the service contract.
>> Our annual cryoplatform service contract is $19.5k.
>
>> Wow... I thought our compressors were old! If I quickly estimate that we ran each of them for 10 years running about 75% of the time that comes out to 65700 hours. Max about 80000.
>> The 500 compressor was going just fine when I last had it running (2014). Never had any issues with it in about 10 years of operation.
>> The 800 compressor, which was in fact slightly younger, but I think exactly the same model, and not used quite as much, had been flaky since sometime in 2012- so about 8 years or 52000 hours. It got a little picky about starting- we often had to do minute adjustments to the amount of current going in to the unit. We had thought the issue was the low voltage in the lab- slowly went down to about 195-194V on an average day, and it was down to 190 V one day when we couldn't get the compressor to start no matter what- for sure that was out of spec. But even after we got a boostup transformer and the voltage was up to 210 or so it was still fiddly- often requiring a small adjustment to the current going in before it would turn over and run. Now maybe the low voltage had some detrimental effect (but why on one unit and not the other?). However, once started it ran just fine.
>> For the most part I had cold probes up and running on both spectrometers at the same time, so any kind of chilled water or electrical failure would hit both compressors at once. Again, the 500 had a cold probe in longer than the 800, so for whatever reason that particular unit held up better.
>> That said, I stopped both cold probes because we were (over)due for cold head/adsorber maintenance. I assume that the deterioration in operation was on the cold head side, nothing to do with the compressor, in the absence of any failures on the compressor side.
>
>> I have had a cryoprobe in use since May 2005 and have replaced the helium compressor twice. The first time was in December 2007 and the second in June 2015.
>> The first compressor overheated several times due to cooling issues, and finally become blocked due to water problems. I then replaced my water heat exchanger and used different water and got a much better life from the second unit. The 7.5 years seemed relatively normal to the Bruker engineers.
>> Last year I combined the compressor change with the CP10K, and paid $15,356.88 for the exchange compressor plus $13,500 for the service, plus another $1,500 for labor.
>> When I replaced my water system I bought a much higher capacity heat exchanger to interface with our chilled water supply. This unit has an LED temperature display which I can monitor via a webcam. I have the temperature set at 15C, and change the filter weekly on the input supply to maintain this.
>> As a result of this, I think the second compressor only overheated three times in 7.5 years.
>
>> The wear item in a coldhead helium compressor is the oil. After overheating a couple times, the oil has degraded to a point that it vaporizes into the helium. This can overwhelm the vapor absorber, contaminating the helium, the high-pressure lines, and the coldhead. You don’t want it to go that far!
>>
>> I’m not sure just how to tell when one is on its last leg, but you certainly don’t have to get one from Bruker when you need to replace one. The compressors are the same as used for MRI and are commonly available for MUCH cheaper than Bruker will sell you one. You can get a rebuild from the same company that does them for Bruker (Cool Pair Plus http://www.coolpair.com/ <http://www.coolpair.com/>). Same for the high pressure lines. Bruker wanted $15,000 for one new 30’ line and we bought one brand new from the manufacturer for less than $2000.
>
>> my experience about the cryoprobe:
>>
>> How long has your helium compressor been operational?
>> around 100,000 hour
>>
>> Have you suffered a helium compressor breakdown?
>> yes, the temperature from the compressor increase and switch off. In cryotool you see the massage "compressor breakdown" or "trouble with compressor".
>>
>> And are there any telltale signs that the failure is imminent?
>>
>> How expensive is it to repair/replace?
>> I don't know the price form Bruker, the price from Sumitomo (manufacturer) is around 5,000€.
>
>> We have a CPDUL cryoprobe with outdoor air-cooled compressor that has been operational since 2003. Mirroring your experience, our service engineers are amazed that the outdoor compressor still works after 13 years (at ~110,000 hrs).
>> The engineers suggest the indoor water-cooled compressors are generally more reliable than outdoor units, presumably due to avoid exposure to the elements.
>
>> We lost one of our 2 after about 5-6 years and our second is still going at a bit longer than 10 years. I recall that instability was seen as wild swings in heater power levels and the oil capsule temp was running very high on the compressor even after a condenser coil cleaning and cold head replacement (and that the oil color had changed?). I was told that if/when the oil temp gets too hot, it starts throwing it into the helium line and contaminating the system. So the decision to swap it out was made since they could not get it to work in the needed range.
>> Both are outdoor air cooled which I hear tend not to last as long as the water cooled as long as the flow is clean and strong. Repair was under contract. I think a replacement is about $18.5k for the part exchange and probably 23-24k total installed.
>
>> I have 5 spectrometers with Bruker cryoprobes for the last 10 years or so. I will share my experiences. In the beginning I did not have contracts on them at all. I also have no contracts on spectrometers as I am a former Bruker employee and can save a ton of that money.
>>
>> Compressors generally should last 90-100K hours. Some more some less. Bruker may caution about 70k.
>> I began to lose a couple of compressors about 6 years in. One was their fault one was our water. After I paid for one I decided that cost of the contracts was worth it and added service contracts on my five CP systems. One other motivating factor for me was it also includes the annual CP10K cost that I was spending anyway.
>>
>> You do not need to also cover your spectrometer.
>>
>> As for your original post I used to push the CP10K time before I had the contracts. It was not uncommon for me to get 1.5 to 2 years between services. There is no drawback really other than it may come up unexpectedly that it will not cool down at all anymore and you are at Bruker’s discretion as well as funds to get back up.
>
>> We have a carbon optimized cryoprobe on an AV500 and we have a Bruker service agreement for it. It covers the cooling unit and the Helium compressor. The cost per year is $19,480. There is a separate cryoprobe agreement that is $4,525. We are a heavily used facility so we just include the cost in our charge calculation.
>
>> We have had 3 cryoprobes for 12+ years. We initially had many problems with the cooling water on 2 of them - it was intermittently way too hot. It took us (and Bruker) several years to figure out why we had so many problems (the coldheads ratcheted). Anyway, with those qualifications: one died at about 35,000 hours, and one died at less than 20,000 hours. Bruker replaced those free of charge because they had had so much trouble diagnosing our problems. After that, we resolved our chilled water problems and things have gotten much better. On those two instruments, one compressor has lasted over 50,000 hours, and the other one also lasted about 50,000 hours, before we replaced the whole system.
>>
>> Our third cryoprobe never had serious problems with the cooling water, and its compressor lasted about 70,000 hours before it died. That's the longest-lived one we've had so far. I definitely agree with your service engineer that 90,000 hours+ is much more than average. I'm also convinced that the colder you can keep them the longer they will last.
>>
>> As far as I know, there are no telltale signs that the compressor is about to go. But you can take temperature measurements on the capsule - they might give you an indication how it's performing. You'd have to get details from Bruker. The exchange price on the compressors is around $20,000. I think you can plan on paying that much (although in theory it can be as low as $10,000). We don't have any service contracts.
>
>> we have two outdoor, air-cooled helium compressors (made by Sumitomo) that are part of our 600 MHz cryoprobe systems.
>> We had a failure of one of these during it's first year of operation and Sumitomo replaced it (manufacturer's defect).
>> The symptom was "knocking" of the cold head cause by hydrogen ice build up which caused friction and thus the pin connecting the two stages of the cold-head piston to break.
>> The H2 gas apparently came from breakdown of the oil (caused by heat) in the compressor and somehow got into the pressurized He gas line.
>> We replaced the other cryounit's compressor after ~ 8 years of continuous operation as well once we started to hear cold head knocking even after repeated warm up and flush cycles. At that type we also replaced the helium supply lines.
>> From memory, the cost of replacing the outdoor unit was about $20,000 (not including crane rental to remove and install new one)
>
>> we have severaly ones running (500-900 MHz, since ca. 2000), and replacement was usually due after ca. 10 yrs
>> or so (if you're lucky maybe 1-2 yrs. more)
>>
>>> * Have you suffered a helium compressor breakdown?
>>
>> yes, obviously
>>
>>> * And are there any telltale signs that the failure is imminent?
>>
>> not that I remember - except for the old age, which made us expect something in this direction.
>>
>>> * How expensive is it to repair/replace?
>>
>> EXPENSIVE. don't remember the exact numbers, it was some time ago .. well, it was a complete replacement,
>> so the price of a new one. Which - if you break it down to a per-year depreciation, comes to something on
>> the order of ca. 50% of the costs of yearly cryo maintenance.
>>
>> And yes, we did have several shut downs to due power outages etc., I think that's normal, and
>> I would guess (!) a warm-up once or twice a year wouldn't matter much.
>
>
> --
> Dr. Bob Berno
> Manager: McMaster NMR Facility
> Department of Chemistry & Chemical Biology
> McMaster University
> 1280 Main Street West
> Hamilton, ON
> L8S 4M1
> (905) 525-9140 x24158 or x24686
> Fax: (905) 522-2509
> http://macs.mcmaster.ca <http://macs.mcmaster.ca/>
>
> -------------------
> If you have an accommodation need for a planned meeting,
> please e-mail me directly and I will do my best to make appropriate arrangements.
> Should you require any materials sent via this e-mail address in
> an alternate/accessible format, please let me know.
Received on Tue Aug 29 2017 - 11:17:49 MST