Thanks George but I think you misunderstood my post. The corrosion is not happening in the compressor itself but in the pneumatic valving that controls the pneumatic motor. This is happening on offshore oil/gas production facilities and I suspect the compressed air for the motor (they are...
I'm running a compressor class and I have one delegate who has had multiple problems with booster compressors for dry gas seals. The problems seem to be mainly from the pneumatic air supply causing corrosion in the valving to the compressor pneumatic motor. I have personally not seen this but...
If a gear pump is giving reduced flow (assuming no flashing of fluid) and the gears are keyed to the shaft then the cause MUST be slippage of fluid past the teeth. That can be due to wear of the casing to tooth clearance or (and I have seen this much more often) scoring or wear of the gear end...
Does anyone know if 7% Ni steel is now approved under API620 or AME VIII for LNG storage tanks? I know this has been used in Japan and the Middle East with huge cost savings but if I'm building a tank in North America I don't know if it's allowed.
Ron Frend
http://www.predicon.net
Hi Vibsofistio, I had a quiet new year's eve. In Houston after a long flight so missed the celebrations but no hangover on New Year's Day. Result. [bigglasses]
I'm at a loss as to why this is happening. From what you say you have a high (24mm/s) 1X axially at fan speed - is this ONLY on...
Hey vibsofistio,
I hope you had a merry Christmas - not working too hard?
Looks like you have an installation alignment issue on the taper roller bearings. The inner cup on both bearings and the inner race on one bearing are out of tolerance in the axial direction. If you have bearing...
Hi Meshry, If the seal faces are wearing out and the hydraulic balance is not too high and the barrier fluid is a good lubricant then the carbon is too soft a grade. Go back to Flowserve and ask them for a harder wearing carbon. You then run the risk of the carbon cracking more easily but it...
Hi Meshry. Have alook at SEALING SENSE from Oct 2013 www.fluidsealing.com/sealingsense/Oct13.pdf
The paragraph on water as a barrier fluid describes the temperature limitations - it freezes at low temperatures but at higher temperatures water is a terrible lubricant and will cause seal...
Meshry, I have some questions
1) Can I ask why you are using potable water as the barrier fluid? It is more usual to use a hydrocarbon with better lubrication properties on a crude oil pump.
2) I also assume that when you say the seal chamber pressure varies from 6 to 72 barg that this is...
Good question NovaStark. I found the best way to display the most pertinent information was to use a low pass filter to show nothing higher than (about) 10X. Anything more than that and you get a lot of noise that makes it very difficult to see the true orbit. If you filter at 1X or even at...
Orbits are simply a plot of the X displacement sensor output against the Y output in the time domain so effectively you are looking at the movement of the centre line of the shaft. If there is some unbalance but no other loads you would expect the shaft centreline movement to follow a circle...
Are you absolutely sure this is unbalance? The reason I ask is that in almost every case of high axial vibration on a belt driven fan the cause has been misalignment. It's quite possible that the motor could be aligned to the belt but the fan may not be. My rule of thumb has always been if...
Thanks LittleInch, that's exactly my thoughts too but I thought I would see if anyone else had this problem. I also checked the ABS "Guide for Building and Classing Subsea Pipeline Systems" and in Chapter 3, Section9 paragraph 5.13 it states
"Cathodic protection design is to be performed...
We have an application where DoT requires cathodic protection on the inner pipe on a 12x16 "pipe in pipe" subsea pipeline. Does anyone have any experience of this? I've talked to several suppliers and our own pipeline engineers with no luck. The only suggestion the contractor has come up with...
Well said Romke.
If the bearing has failed due to fatigue then you will see cracks (or bruising). Changing to a higher strength babbitt will help in that case but the rule of thumb is to make sure the hardness of the babbitt must be no more than 1/3 the hardness of the journal. If you do...
The main reason for having a non-circular bearing is to avoid oil whirl. With a well designed "simple" journal bearing (your words) the maximum pressure in the lubricant happens somewhat after the bottom centre line of the bearing (say 7 0'clock if the shaft is running clockwise). As the speed...
The tolerances for shaft diameters mentioned in API610 11th edition are
1) ANSI/ABMA 7, Shaft and Housing Fits for Metric Radial Ball and Roller Bearings
2) 6.6.4 All shaft keyways shall have fillet radii in accordance with ISO 3117.
3) 6.6.7 The shaft-to-seal sleeve fit(s) shall be F7/h6 in...
Just to add a little input here, I had a similar problem way back in the 80's in Oman on a 3MW shipping pump motor after overhaul. In this case the highest vibration was axial and the cause was that the thrust pads had been put back on the wrong sides. In other words the motor was now running...
