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marksl

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Reply with quote  #1 
Hi,

Does anyone have experience using a videoscope to carry out internal pump inspections. I have a client running 4 booster water pumps which are centre hung with two impellers. Normally this client would carry out said inspection by dismantling each pump which is a very costly exercise. The pump casing over the impellers have a water port with a fitting and hose where water is used to lubricate the two mechanical seals. The client is suggesting we enter the pump through these 3/4" and 1" ports and inspect the internal casing coating and the surface condition of the impellers blades.
My weapon if choice (at this stage anyway!) is a FLIR VS70 videoscope with a wireless 1M flexible short focus camera with 4 way articulation. My concerns are as follows;
1. Will the camera be able to articulate sufficiently along its 1M length to be able to inspect the entire casing. I'm not talking about the 360 degree articulation of the camera tip but the 1M flexible cable when the cable is passed through a 3/4" inlet?
2. Secondly will the camera cable "bend" sufficiently to move between the impeller blades and into the expeller blades to inspect them for pitting?

Thanks in anticipation
MarkL

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Reply with quote  #2 
Hi Mark, I can only comment on that I have used a very cheap video scope I have , 600 mm flexible tube with a light and fibre optic light on the end and inspected large Bandera Helical 3 shaft gearboxes for wear through the oil filler bung on the top, and in that case it worked a treat, we could see sufficiently on the screen despite its low resolution. 
What I can say is this, do you or your customer know what you are looking for? as in if you identify something on the screen will it be sufficient in deciding the outcome of the inspection?
Do you have a similar pipe or some hard to reach application you can practice on first, so as not to look silly if you arrive at the job and cant make it work?
Walt Strong

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Reply with quote  #3 
I have only limited experience with fiberscope. I few concerns and suggestions:
  1. Inspection plan, as Mark said
  2. Access from suction, case, and discharge openings determine view
  3. Good lighting is essential
  4. Navigation and knowing which way is up
  5. Documentation notes to match images/video
  6. Make sure nothing falls off or scope gets stuck!
Walt

marksl

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Reply with quote  #4 
Here is a picture of the split axial style pump that needs inspection. You can see where the two impellers are located and the ports in the casing at the top of the impellers which will be the camera entry point Duoflo.jpg 
Noknroll

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Reply with quote  #5 
I think the inspection capability will be quite limited as in access/visibility to all key areas wont be achievable. Thats just based on the camera I use which sounds similar to markl's. Getting the "head" of the scope throuh some small clearances will be a challenge, but hey, if the client doesnt have high expectations by all means have a play.
Walt Strong

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Reply with quote  #6 
I would rotate the shaft to allow each impeller vane to pass by. This might be good for the discharge end of the vanes. If you cannot "see" back side of vanes at inlet (Cavitation damage), wear rings, balance disk/drum, then any visual inspection is very limited. 

Walt
marksl

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Reply with quote  #7 
Quote:
Originally Posted by MarkL
Hi Mark, I can only comment on that I have used a very cheap video scope I have , 600 mm flexible tube with a light and fibre optic light on the end and inspected large Bandera Helical 3 shaft gearboxes for wear through the oil filler bung on the top, and in that case it worked a treat, we could see sufficiently on the screen despite its low resolution. 

I'm worried about resolution (The FLIR VS70 is 640 x 480) and also about the effectiveness of the LED lights on the camera tip.

What I can say is this, do you or your customer know what you are looking for? as in if you identify something on the screen will it be sufficient in deciding the outcome of the inspection?
Do you have a similar pipe or some hard to reach application you can practice on first, so as not to look silly if you arrive at the job and cant make it work?

I'm thinking I might try and borrow a demo unit and practice on some pumps we have in the warehouse.
marksl

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Posts: 124
Reply with quote  #8 
Quote:
Originally Posted by Walt Strong
I have only limited experience with fiberscope. I few concerns and suggestions:
  1. Inspection plan, as Mark said
  2. Access from suction, case, and discharge openings determine view
  3. Good lighting is essential
  4. Navigation and knowing which way is up
  5. Documentation notes to match images/video
  6. Make sure nothing falls off or scope gets stuck!
Walt



Thanks for the comments Walt, I guess I haven't considered knowing which way is up!! I think the camera will be able to navigate the internal casing and the impeller blades but I not so sure about moving through the blades into the expeller blades and that's where the pitting has occurred in the past. Also not sure if I should get a camera with short or long focus abilities. A long focus might help overcome the limitations with navigation.
Walt Strong

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Reply with quote  #9 
"I guess I haven't considered knowing which way is up!!"

This was no joke. I found that I could get disoriented and lost; the few times I used a fiberscope. Do not use after a few beers!

Walt
marksl

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Reply with quote  #10 
Quote:
Originally Posted by Walt Strong
"I guess I haven't considered knowing which way is up!!"

This was no joke. I found that I could get disoriented and lost; the few times I used a fiberscope. Do not use after a few beers!

Walt


I wasn't treating the comment as a joke. I knew exactly what you were saying !
VibGuy~5

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Reply with quote  #11 
We have a borescope with an articulating head, 6.1 mm dia, good LED. Getting it in a 3/4" or 1" port would be no problem, but getting it beyond any impellers to where you want to go, that's a matter of a gentle push and pull -a soft touch.
It wasn't cheap. The more expensive option had stereo cameras, so could take a pretty accurate 3D image of scratches/damage, but the budget didn't quite go that far.
marksl

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Reply with quote  #12 
Is anyone using a FLIR VS70 video scope. It would be great to hear some first hand feedback
MarkL

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Reply with quote  #13 
I think Flir's video scopes are basically 'Extech' technology whom they bought a few years back, and from what I have seen they make good kit, sorry I have nofirst-handd experience with them though.
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