We have 2 POSVs in same service (Liquid Ammonia + Amines) one in line and the other acts as stand by. But coincidently in both the POSVs, same kind of O ring failures were observed. Please see the attached pictures for the extent of damage to the O rings. For additional information I have also attached schematic diagram. Make: Anderson Greenwood The operating condition is 220-240 barg, POSV set pressure is 280 barg. Operating temperature is 180 deg C. The existing material for O ring used is...
Hello Vb experts, here i attached damaged bearing images please give some possible causes of this catastrophic failure. bearing NU1052 -installed on May 2016.......damaged on Jan 21st 2017(Running time 7 month only) we inspected vrm motor in every fourth nightly , vibration and temperature parameters are in normal condition below 2mm/sec and below 75 degrees. but on January 21st we observed abnormal sound at Motor De side so we inspected the bearing with vibration analyzer.there is a sudden...
We have a 750 KW Ring Granulator Crusher. The Crusher was undergoing heavy vibration. It was discovered that the ND Bearing radial clearance had increased abnormally. The bearing was replaced and the machine was put into operation. At no load the following vibration readings were taken in mm/sec: ND End H-10 V-5.4 A-5.4 Drive End H-5.4 V-2.4 A-4.8 However when the machine was run under load the following readings were taken: ND End H-9.4 V-6.9 A-10.3 Drive End H-6.9 V-4.7 A-12.8 What is the...
BUS BAR CONNECTION BETWEEN SLIPRING & ROTOR WINDING IS MELTED, EACH PAHSE IS HAVING TWO PARALLEL WITH TOTAL FOUR BUS BAR(WIDTH 35 mm & THICKNESS 4.5 mm) DID ANYBODY FACE THIS KIND OF PROBLEM,PLZ SHARE YOUR VIEWS NAME PALTE: 5300 KW,11 KV,323 A,1890 V,1690A RPM 997
We have been facing "Lock-up" issue in Floating Ring Type Oil Seals of one of Centrifugal compressor at our site, which is evident from vibration behavior of the machine. Would appreciate a comment on the following: 1. What are the recommended online troubleshooting practices to resolve the issue of Lock-up 2. Would it help if we increase the radial clearance b/w rings and shaft sealing sleeve
Hi Friends, In one of the planetary gearbox am getting a frequency of 4.55 Hz.Vibration levels are in between 5 to 6 mm/sec.The teeth details is as follows Input RPM:1489 Pinion 25 Wheel/Helical 67 1st Stage 2nd Stage Ring Gear 128 77 Planet Gear 51 28 Sun Gear 25 19 i am suspecting defect on 1st stage ring gear(correct me if am wrong). Please let me know is there any other possible reasons for getting 4.55 Hz.Please find the spectrum for reference. Thanks in advance.
Hi all, we had issue with sleeve bearing failure, the issue began with high temperature until the babbitt failed, we suspect the oil ring is very heavy. Please, Can you share experience in this kind of problem.. *how can we know if the oil ring was bad selected? *diameter of shaft is 2,6 inch, rpm= 3600
We have Reciprocating type Dresser Rand make Natural Gas ( BOG) compressor.. It is 2 stage 4 cylinder compressor.Recently we have done complete overhauling of the machine and replaced all piston ring and rider ring with new one. In HP NDE Cylinder Piston rubbed the liner after only 50 hrs of running hour. With same piston ring and rider ring we are getting more than 4500 running hour life. In one piston there is 2 Piston and 2 rider rings. Construction of rings is Rings Split type. What are...
Please provide additional details, do you have any photos of damaged liner? Rubbed the liner is a very broad term, rubbed where in the liner? new liners? packing? any measurements taken on the liner to prove it is straight and not worn? If the piston touched the liner, ring rides too deep in piston, egg shaped liner, worn piston holding pin, bent rod to name a few possible starting points Dave
dear sir because of failure event after overhauling you should check all installing and assembly procedure .do you have any vibration condition monitoring data during 50 hrs?any protection like rod drop proximity sensor ? are you sure about operating process parameter during that time ?
Was the cylinder starved of processed gas? How about the end devices that was to shut down the unit for excessive vibration are they properly installed and working? from your explanation though not too clear- Rod reversal due to lubrication issues might be the root cause.
dear sir have you n checked the suction and discharge valves ? if you sure about maintenance of all components and installation procedures ,you should looking for cause around operation after overhauling .for example be sure about condensate gas or liquid drainage during operation. best regards
First off, this is a synchronous or wound rotor motor (not specified which). These are very different from induction motors. You treat both of them the same way. First look for physical damage. Is any of the wiring stretched out of shape like it was ripped apart by something mechanically? If not, move on. This is rare but it does happen occasionally. It is very obvious because the wiring gets stretched and distorted, tie downs ripped apart, etc., with little heat damage. Move on to checking...
Dear sir , you have replaced bearing but what if the clearance increased due to Bearing plummer block wear in inside .You need to check the clearances once again and need to place a shim between bearing outer race and plummer block inside area .And need to check Bearings tightness on shaft . If you have the spectrum ,please post here .So that we can understand the problem clearly .At this point according to your data , i suspect bearing looseness . Please post your findings .
https://www.slideshare.net/Tom...resentation-2015-new slide number 38, very good information, it would appear from your images that the oring melted or creeped due to excessive temperature Dave http://www.marcorubber.com/o-ring-troubleshooting.htm http://dupontelastomers.com/Pr...tails.asp?show=div04 http://www.dupont.com/products...tant-elastomers.html http://www.kalrez.nl/Products/...gGuide/extrusion.asp http://www.kalrez.nl/Products/...ngGuide/cracking.asp ...
A Is the helical stage speed increasing or decreasing? The reason I ask is if I assume a reducer, then the gear rotation is 555.6 RPM (9.3 Hz) and 1/2 of that is 4.65 Hz. It could be a coincidence. But more info would be good. Any cross section drawing you can post or model number?
Hi john, Helical stage is speed reducing and model number is CPNHX-244 and am also getting a spectrum with sidebands of 4.68Hz difference at 195.31 Hz(which is close to 193.67 Hz(1st planet GMF)).Please find the spectrum.
the spectrum is shock pulse spectrum and unit SL is shock level unit . I don't know exactly the relation to other common units but i think its same as peak vue in Emerson and envelope spectrum in others ,in SPM instruments we use shock pulse .
I am not familiar with the SPM technology and all I can find relative to "SL" is this content from the SPM site http://www.spminstrument.com/M...e-Monitoring/dBmdBc/ . "One unit for amplitude in an SPM spectrum is SD (Shock Distribution unit), where each spectrum is scaled so that the total RMS value of all spectrum lines = 100 SD = the RMS value of the time record. The alternative is SL (Shock Level unit), the RMS value of the frequency component in decibel. Alarm levels are manually set...
i doesn't have any reference.we just trend the defect value.In some cases even though the SL value is below 1 the bearing has damaged. Case 1 The overall SL value is below 1 but the bearing got damaged and outer race cracked. Case 2 The overall SL value is 13 but bearing is having small pitting and still we are running with the same bearing. Actually forgot about 4.55 Hz ????
I'm hesitant to make a suggestion based on technology (SPM) that I know absolutely nothing about. But in your initial statement you mention "Vibration levels are in between 5 to 6 mm/sec". That level isn't all that high. What other information, like oil analysis and chip detector status are you collecting?
We do oil analysis and gear particles are not mentioned in the report and bearing particles of size 40 microns is observed in marginal quantities. We are planning to open the gearbox in one or two months.will let you know the status once opened.
Quote::: "I don't know exactly the relation to other common units but i think its same as peak vue in Emerson and envelope spectrum in others ,in SPM instruments we use shock pulse . " What suggests SPM is the same or resembles Peakvue and envelope data? Is it because a high pass filter is, or has to be, used? If there are high pass filters used, that may be an answer to one of your concerns in the examples "1" and "2" posted. Thanks and Have a Great Day, Ralph
If this is related to classic SPM and for all I know it should be, the accel resonance is used and that should be like 32kHz so if the fault do not excite or get modulated or maybe modulate that freq. it will not show much. It may as in most demod or similar systems have limited trend stability. Only my 1SEK info. Olov
I would suggest you trend the frequency and see what it does moving forward. In a statement early on, I had tried to express to you that I didn't think the level was that high. Gearing of any type is a great generator of sum and difference frequencies so that may be a cause. I would also suggest you ask Eickhoff the anticipated frequencies of the gear.
i don't have a pic of FFT but Dominant peak is 1X and presence of 2X , 3X and bsf harmonics with its side bands.the velocity values are in with in limits only but how this catastrophic failure happened in 7 months period.
The shaft is undersized, this allows the inner race to deform because there is not enough contact to stop the inner race from deforming. The size of the KW would also tell me there are several thousands of lbs of weight on the bearing If the part of the bearing inner race that contacts the shaft was very clean then I would say the shaft was oversized and this would cause the inner race to crack http://ctcbearings.com/ctc%20b.../FailureChartpdf.pdf Looks like you could have electrical...
This is Vertical cement raw mill motor , there is a presence of high impacts and high temperature also its look like thermal crack for me.is there any chances like failure due to temperature in lesser period ?
Since there is less contact between the bearing and the shaft, vibration values are to be low only. But the increase in the temperature is a very clear warning. That is the reason newly installed bearing temperature monitoring is mandatory. Luckily there is no damage to the shaft.
As suspected....the axial face of the bearing also shows it was "moving" on the shaft. If this just started to happen with this motor, fixing the loose fit on the motor shaft should fix your problem. Do not overlook the bearing housing fit also...... Dave
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