Skip to main content

Tagged With "axial"

Topic

0.6 pk IPS High Vibration at Large Axial flow pump

Ayaz Ahmed ·
We are facing high vibration an axial Flow Morris Type 54” MPAF pump which is designed for re-circulation of Caustic Liquid. This is an overhung design pump with no bearing support on the Non drive end side and pump is directly installed to elbow of a large pipe. Following are the specifications of equipment Flow: 20,000 m3/ hr. RPM: 242 Driver: 1185rpm, 530 kW Motor Driven through a Gear box and universal coupling Observations:- Highest Vibration at P1H (Pump Inboard Horizontal) of 0.5-0.6...
Topic

Axial End play limits for motor provided with ball bearings

vikramdeeps ·
Hi Guys, Can you help me with Axial End play limits for motors provided with ball bearings.Any standard which says the limits for end play for motors?
Topic

Overhung fan

azizsuahid ·
Hi guys, happy weekend ") i need some help regarding one critical equipment in our plant. It's an Overhung Fan having high overall and ge. At lower frequency side of the spectrum, i can see running speed harmonics as well as of sub-harmonics of 1/3x , this has occurred after assembly and replacement in March 2016. During the balancing work in march, i found so many weights attached to the fan from previous balancing work, we ignored and continued with balancing(adding another weight) , and...
Topic

Axial or Thrust Position Measurement Using Proximity Sensor

Vibrave ·
Can anyone clarify , the axial or thrust position measurement using proximity sensor is AC or DC signal? What is mean AC coupled and DC coupled?
Topic

Axial Vibration increases with change of direction

CharlieRB ·
ue December 05 2017 08:06 AM All; We have a furnace with seven over hung fans bolted to the side of the furnace wall. To reduce a beat frequency every other fan is operating at a different speed, 1080 and 980 RPM. These fans operate in the clockwise and counterclockwise directions and herein lies the problem. All fans run well in the clockwise direction however, during the cycle the fans will change direction and run in the counterclockwise direction. Immediately the 1 times vibration...
Topic

Axial vibration on Press suction roll

Jack1954 ·
. I have a motor to a gearbox and gearbox output shaft coupled with a press suction roll. The roll is vibrating axially and started suddenly. My first thought pointed to a U-Joint in the shaft of this roll. U-Joint shaft replacement made no difference. I don’t think the drive side bearing cocked suddenly or the roll jumped out of alignment. I am thinking operations may have rotated the vacuum box inside and now it’s excited. Nothing is getting any worse and it’s mainly on the drive side.
Topic

Axiall movement

aziz58 ·
Dear all What courses of high axial movement at gas turbine? I face to axial displacement alarm limit of Siemens Sgt 600gas turbine. They have six sets of gas turbine which only one of them have high axial movement. All operation conditions and process were the same. Pls, share your opinion. Best regards
Topic

4x Axial Vibration Frick Ammonia Screw Compressor

DaveyBoy ·
Hey everyone, I have a 3600 RPM motor (direct coupled) driving a Frick Ammonia compressor. Back in August 2019 all was good, when I took readings in October 2019 there was a high 4x spike in the axial direction (0.471 inch/s RMS). The alignment and coupling were in good shape. The motor was sent out for rebuild. The motor was re-installed about 2 weeks later and the 4x vibration had come right down (0.071 inch/s RMS). All other vibration was good as well. About a week and a half ago there...
Topic

Another Resonance Question

Mile High_PumpFE ·
Have another resonance question..... the is the AXIAL plane of a thrust end bearing housing. Please see the attached document that shows a vibration trend with 3 data collection points - please pay attention to the 2x peak as speed increases through the test point. You can see how it is moving closer to resonance. Also please notice the vane pass peak at 198.25 Hz as the pump increases in speed. There is a resonant like response at the highest speed (black line). If you look at that spectrum...
Topic

1600 kW 3 Phase AC motor axial vibration

Mukesh Chandrawanshi ·
I have face a new vibration problem in 1600 kW AC motor which is associated with fan. in this equipment vibration is high in vertical & Axial direction in motor Drive End & Non Drive end vibration is more than 3.5 mm/sec in axial direction whereas horizontal vibration is 0.85 mm/sec. Motor has 8 pole , and that time running rpm is 337.5. Wondering is that we found a peak in vibration signature at 30337.5 cpm and amplitude value is 3.20 mm/sec . also find side band of 6.25Hz (337.5...
Topic

2x Axial Vibration

ConfMx ·
Hi guys, i,ve a problem with 4Poles Generator 8Mgw in Turbocompressor Solar Mars (Turbine-gearBox-Generator), High Level Vibration Axial NDE 2x (2x1800=3600cpm), 0.26 in/seg(pk). The Last test were with change Load level (decrement from 8Mgw to 0.5 Mgw), Decrease in amplitude is observed due to the change load level: 8Mgw, Level vibration @2x= 0.26 in/seg(pk), the last level (0.5Mgw)= 0.08 in/seg(pk). View Anex. Phases: NDE Axial 1x= In fase (4 axial points, 12,3,6,9) 2x= OutFase 90degres...
Topic

Balancing of fan

vishal sharma ·
Dear all i am dealing with a RAW mill simple supported system fan 2500 kw motor with 990 r.p.m . The spectrum in DE bearing showing 1X with an amplitude 3.8mm/s overall vibration is 4mm/s in DE bearing in horizontal direction. vertical: 1.2 mm/s Axial: 1.4 mm/s but at NON DE side bearing we are having 5mm/s overall vibration in horizontal direction. the spectrum in NDE bearing showing 1X with an amplitude 3.9mm/s . vertical vibration is :1.8mm/s Axial: 2.4 mm/s by doing time wave form...
Topic

Balancing duel rotor variable pitch axial fans

John.OGE ·
We are a coal fired power plant and one of our units has large duel rotor variable pitch axial fans for Induced Draft made by Westinghouse. Does anybody know balancing experts (SME) that are familiar with these kind of units?
Topic

Compressor have abnormal behavior of axial movement

Unplugged.Charles ·
Hi everyone! I'm suffered with one centrifugal compressor which have abnormal behavior of axial movement. Rotor axial position is moving to inactive side gradually. I would like to hear your opinion for overhaul work. This compressor is overhung type and driven by motor (3746rpm). And this machine is compressing cycled gas from 10.9 PSIA to 18.3 PSIA. Last overhaul work 2015, thrust end play was lager than allowable value(0.33 ~0.406 mm ). So adjusting plate thickness was changed and end...
Topic

Diesel Generators Engine side Axial vibration High on a 17000 DWT Chemical Tanker vessel

chary tatta ·
Dear AMP team, This case is about 2 diesel generators (DG) Engine free end Axial vibration found high. Attached is the DG vibrations recorded on Alternator end- Satisfactory, Engine end Axial vibration High. Attached the vibration velocity FFT spectrum, further any other files required like time wave form, Acceleration FFT and time wave forms shall be posted. Engine rpm is 900. Generator appearance in images for your kind understanding. Appreciate your participation on this case study.
Reply

Re: seal air fan (Radial Fan) Axial Vibration

Walt Strong ·
" that 7.6 orders matching with bearing outer race but after checking the bearing outer races are normal" You have outer race fault frequency with 1xSS sidebands (modulation), so it sure looks like an outer race fault! How did you or someone actually "check the outer race"? Most bearings require destructive disassembly (cut apart) to actually see the full bearing race surface. Don't get lost in a pile of data! Walt
Reply

Re: seal air fan (Radial Fan) Axial Vibration

Shurafa ·
Were these spectra collected before after the "bearing checks"? Did you replace the bearings or you reinstalled them? It looks there is a bearing defect. Regards-Ali M. Al-Shurafa
Reply

Re: seal air fan (Radial Fan) Axial Vibration

y@sh ·
Above spectrums are After checking the bearings and alignment and we find inner clearances but there is no outer race defect physically
Reply

Re: seal air fan (Radial Fan) Axial Vibration

y@sh ·
We check the bearing clearances with feeler gauge inner and outer
Reply

Re: seal air fan (Radial Fan) Axial Vibration

y@sh ·
We disassemble the both de and nde bearing and checked physically but there is no Outer race defect
Reply

Re: seal air fan (Radial Fan) Axial Vibration

y@sh ·
bearing images
Reply

Re: seal air fan (Radial Fan) Axial Vibration

y@sh ·
BEFORE ALIGNMENT
Reply

Re: seal air fan (Radial Fan) Axial Vibration

electricpete ·
[quote] inner race clearances was 0.3 mm.[/quote] Can you explain more about this measurement? I hope it is not between bearing and shaft (that should not be clearance) What style bearing is it?
Reply

Re: seal air fan (Radial Fan) Axial Vibration

montaser ·
I advice you to make mark using (correction pen) between the bearing outer race and lower part of housing and another mark between bearing inner race and shaft, and keep the fan running for some hours, then stop and inspect the marks position for the possibility of bearing rotation inside the housing.
Reply

Re: seal air fan (Radial Fan) Axial Vibration

y@sh ·
Tnq for reply its not b/w shaft and bearing ,clearances are b/w balls and bearing inner ring.
Reply

Re: seal air fan (Radial Fan) Axial Vibration

y@sh ·
thank you sir but it is a heavy equipment . so,it's impossible to open the machine at present conditions.
Reply

Re: seal air fan (Radial Fan) Axial Vibration

Jim1 ·
Oil filled housing? Did you sample the oil? What caused the satin finish on the rollers and inner raceway?
Reply

Re: seal air fan (Radial Fan) Axial Vibration

Walt Strong ·
Y@SH, I looked at your three photos. None of the photos show the surface of the outer race/ring that is in the contact path of the rollers. The bearing would have to be destructively taken apart to do so. Therefore your limited inspection does not prove or disprove an outer race defect. The only way to do that would be to remove the grease and cut the bearing rings apart. You can save that activity for a later date when you change the bearing. If you actually put in new bearing when those...
Reply

Re: High Vibration at 2X

Dan Timberlake ·
What critical speeds / resonant frquencies are claimed by the OEM?
Reply

Re: High Vibration at 2X

JCP420 ·
Sir, yes I asked from OEM. They said first critical at 25 to 27 percent, second critical is at 58 percent of the 15000 rpm. 72 to 100 percent there is no critical speed because OEM acceleration rate between this band is 0.50 percent on each click of speed increase and decrease. From 0 to 72 percent turbine acceleration is fast and stay on 72 percent. If u see the signature / spectrum the horizotal and vertical is almost same but vertical is slightly less in amplitude.
Reply

Re: High Vibration at 2X

Shurafa ·
What is the name of this vibration analysis software? Regards-Ali M. Al-Shurafa
Reply

Re: High Vibration at 2X

JCP420 ·
NVGATE and hardware is OR 36
Reply

Re: High Vibration at 2X

John from PA ·
Usually these things are built with compliance to API 617. If so, do you have any proximity probe data?
Reply

Re: High Vibration at 2X

JCP420 ·
Sir no option for proximiry, only velocity transducer or accelro meter can be used. The data is captured/measure on diffuser right after the 11 stage axial compressor
Reply

Re: High Vibration at 2X

William_C._Foiles ·
Being built to API 617 doesn't say much sometimes. Vendors, including this vendor, take many exceptions. On the bright side, GTs are for the most part a standard part. 2X can indicate a serious problem, particularly if it has changed or is changing. Look for changes between starts and while operating. Coastdown and startup plots, Bode and polar, for the 2X can be very helpful in evaluating any changes. Amplitude and phase, both rectangular and polar formats, of 2X while operating (at speed)...
Reply

Re: High Vibration at 2X

Gary Stacey ·
Are you thinking shaft cracks Bill? Gary
Reply

Re: High Vibration at 2X

Rotate ·
I had something similar happen to me on a Centaur. Vibration was fine until ignition of GG turbine. The PT turbine bearing vibration amplitude went off the chart and the phase shifted dramatically. It chewed up the coupling (gear type coupling). It turned out to be due to cracks in the turbine exhaust support to the bearing and required replacing the turbine. Bottom line root cause, the weld repair to the exhaust structure wasn't to the manufacturers specification. The exhaust diffuser that...
Reply

Re: High Vibration at 2X

JCP420 ·
Respected Members; One thing i noticed that when bleed valve is closed then the vibration at 2X shows. Before that there is no vibration at 2X. I search the internet regarding effect of bleed valve closed on a vibration in a gas turbine. I have no knowledge about the vibration due to flow effect/ disturbance. Refards
Reply

Re: High Vibration at 2X

Pakhtoon ·
This 2X vibration is not consistent for all speeds, it is during a specific speed span. Is this surely 2X or any frequency near to 2X? If we suspect crack, it must show continuous peak on all speeds even operating speeds. There are no harmonics of 1X or even 2X. There may be no rub or looseness. This peak is due to some transient phase during operation. As u described, no critical speed in this speed span, therefore there may be some flow induced vibration. What actually changes in operation...
Reply

Re: High Vibration at 2X

JCP420 ·
Hello Pakhtoon; The bleed valve close at once. The normal operating speed of 2 shaft GT is 90% to 100 % of 15000 RPM. We face this problem since last 1 year before that this peak is never shown. Actually we Over haul the GT in our facility. You explain due to flow induced yes may be its true, do u have any document which explain vibrations due to flow induced and how we overcome that? Regards
Reply

Re: High Vibration at 2X

Pakhtoon ·
Hi JCP420 You can find this information very generalized in books or literature. Specific information can only be provided by the manufacturer. Because nominal design differences are always there in equipment manufactured by several companies. Do you test overhauled gas turbines yourself or tested by manufacturer? If u test yourself, do their representative witness its testing or you send parameters to them?If No, then have u discussed it with them? Do you overhaul for your field or other...
Topic

Girth-gear Runout

Hossam 2 ·
Helloo Experts. is there a method to check the runout of the girthgear (Axial) or radial using non-contact measurement like using dial gauge but using displacement sensor ? and how it works and what is the senstivity or accuracy of the process. Thanks
Reply

Re: Diesel Generators Engine side Axial vibration High on a 17000 DWT Chemical Tanker vessel

Walt Strong ·
Both engines appear to have the same high vibration with the frequency of 21,000 CPM and harmonic at 42,000 CPM. These frequencies are not integer multiples of engine shaft speed (24.4 X shaft speed). I suspect the frequencies are generated by the accessory gear drive and possibly the lube oil pump. You would need the details about the accessory drive to try to track down the source and ascertain whether there is an issue or not. Walt
Reply

Re: Diesel Generators Engine side Axial vibration High on a 17000 DWT Chemical Tanker vessel

John from PA ·
Review the thread at https://www.maintenance.org/top...ation-on-a-generator especially is this is a 12 cylinder 4-stroke diesel. I say 12 cylinder, 4-stroke because your spectrums are "rich" in 1/2 order components, indicating likely 4-stroke diesel and if the diesel was at 875 RPM, then 21000 cpm could be generated. But in any event the thread I point you too had a similar issue and it required replacement of the rubber elements in the couping.
Reply

Re: Diesel Generators Engine side Axial vibration High on a 17000 DWT Chemical Tanker vessel

chary tatta ·
Greetings Mr. Walt Strong and Mr. John, Thank you for your professional assessment and the replies given from your side most welcome. As per Mr. Walt, Yes, the Diesel generator gear train running with One Lube oil and One Cooling water pump. The acoustic levels are also can be heard from the gear train. The axial high vibration related to Thrust bearing condition too for Axial movement. Appreciate your comment. As this engine is running 4 stroke 6 cylinder Yanmar make 2012 model just 5 years...
Reply

Re: Diesel Generators Engine side Axial vibration High on a 17000 DWT Chemical Tanker vessel

John from PA ·
Any chance you know the firing order of the engine? Even though not a 12-cylinder, I'm not yet convinced that the 21000 cpm isn't engine related.
Reply

Re: Diesel Generators Engine side Axial vibration High on a 17000 DWT Chemical Tanker vessel

chary tatta ·
Greetings Mr. John This is Yanmar marine diesel generator and firing order is 1-3-5- 6 -4-2(Anti-clockwise). I assume that you might have seen Alternator end bearing vibration readings which are in satisfactory zone. Engine free end H V A readings and Axial reading only showing high value with 21.3K and 23.4 K cpm. Thanks and regards Chary TSR
Reply

Re: Diesel Generators Engine side Axial vibration High on a 17000 DWT Chemical Tanker vessel

John from PA ·
Good point that the alternator axial looks OK but the alternator design might explain that. For instance does the alternator even have a thrust bearing or could the rotor just be floating back and forth in its axial clearance? I'd also review what was done relative to the new coupling (was it really a "new coupling" or just the elements?) and making sure the new couplings were installed properly. Sometimes, depending on coupling make, it is recommended that the elastomeric elements be...
Reply

Re: Diesel Generators Engine side Axial vibration High on a 17000 DWT Chemical Tanker vessel

chary tatta ·
Greetings Mr. John Thanks for your interest and reading through the machine to find out the 21 k components analysis. 1. The coupling was opened up in docking but the superintendent was unclear that coupling elastomeric elements renewed for both DG1 and DG 3. 2. The DG are 5 years old as the vessel delivered 2012 from a China shipyard. 3. No much information on dockyard alignment procedure, at a later date when all work done reports submitted by the ship yard to office I will explore it for...
Reply

Re: Diesel Generators Engine side Axial vibration High on a 17000 DWT Chemical Tanker vessel

John from PA ·
Hmmm, I may have messed up. A 6-cylinder, 4-stroke engine at 900 RPM has a firing rate of 2700 cpm. That would be the 3rd order of running speed, not the 4th. The 21600 cpm, what you are calling 21300 cpm is 8X of the firing order or 24X of running speed. As you likely are aware, a diesel has certain criticals that are classified as "very dangerous", "dangerous" and "probably of little concern" (SNAME designations). For example, a 6-cylinder, 4-stroke engine with a firing order of...
 
×
×
×
×