6 replies to this topic

[jawbkk]

Good morning,

 

We are installing a new pump which is a vertical screw pump (Hidrostal) which is ideal for pumping raw sewage.

However, the vibration is known to be twice that of our existing pumps.

 

What is the correct way of preventing this vibration from being transferred to the pipeline (800mm diameter standard wall pipeline).

 

Are there any particular pipe supports that should be used to prevent or help prevent excessive vibrations?

 

Or should I not rely on pipe supports alone?

 

Regards

John

[thorium90]

flexible bellows?

[ankur2061]

Flexible bellows are notorious for being the weakest point in a piping system prone to vibrations. I have seen quite a few flexible bellows getting destroyed due to vibrations transmitted from the pumping system. I would adopt a flexible bellow only as a last resort.

 

One way of dampening vibrations is to provide spring tension pipe  supports instead of the conventional supports to dampen and absorb vibrations. These do help in dampening vibrations albeit to a limited extent.

 

If you are pumping toxic, foul smelling raw sewage containing pathogenic bacteria, I would do a very careful evaluation of flexible bellow mechanical reliability before installing one.

 

Regards,

Ankur.

[jawbkk]

I have no intention of installing a flexible bellows.
First option i guess is to eliminate the source of vibration and i will attempt to change the steel pump support structure for a concrete plinth. Unfortunately this affects the programme and i have to fight my corner!!
In terms of the pipe supports, i was planning on installing some decent structurally strong supports with elastomeric bearing material contacting the pipe.
Has anyone had any experience of using this type of support?
At present, the noise levels for the 8 pumps are 105 dBA. Four hours is max working time which is another program issue.....
Regards
John

[breizh]

http://www.sulzer.co...ting_E00669.pdf

John,

 

Consider this resource to support your analysis.

Breizh

Edited by breizh, 17 February 2013 - 10:06 PM.

[thorium90]

105 dBA is definitely high. Sounds more like you are pumping stones. Loud noises and high vibration when encountered together are typically not very good signs. Perhaps you need to address the excessive vibration problem too. Have you checked what is the peak vibration at various points in mm/s? Is it within tolerance as stated in its manuals? Checked for loose bolts or nuts etc? Misalignment, unbalanced loads? Or the more classic, insufficient lube oil.

Edited by thorium90, 18 February 2013 - 05:24 AM.

[jawbkk]

Many thanks for your replies....

 

We are about to conduct acoustic and vibration surveys so will report back our findings....

 

Best Regards

 

John