pump connection to stop vibration?

[themroc]

We are using a 1KW centrifugal water pump to pump about 80l/min water through a test section in order to meassure pressure drop.
When pumping we encounter strong vibration. This vibration is picked up by the pressure sensor end have a devastating impact on the results.
We thing the vibrations are induced by the pump. In the moment the pump is connected with a 1'' BSP screw fitting, so it is a ridgit connection to the pipework. The pump is placed on a rubber matt. But we thing the ridgit connection could transfer the vibrations to the pipework. Does anyone know the solution in order to decouple the pump from the pipework, ideally suppliers of hardware in order to reduce the vibration. Would pulsation dampenerers be the solution?
thanks for any advice

 

[MechEngInBC]

An expansion joint just after the pump would reduce your vibration if it is coming from the pump itself.

New Line Hose & Fittings carries these

http://www.new-line.com

they have in-house and Aeroquip products.

I have also had a local machine shop build a flanged braided hose in one application which worked well to reduce a lot of pipe vibration.

If you want to issolate the pump you can also put an expansion joint on the inlet side.

Best of luck.



RobHend
"You should always have fun doing your job, if not then it is time to find something fun to do for a job"

 

[themroc]

Thanks this will probably cure the problem.
I had a look on the internet and found a lot of bellis/flexible hoses with flange connections but nothing for threaded 1'' connections does anyone now a supplier ideally in the UK?

 

[ScottyUK]

Try Pirtek - hoses to connect almost anything to almost anything else. Are the threads BSP or some oddball size?

http://www.pirtek.co.uk/

----------------------------------

Sometimes I only open my mouth to swap feet...

 

[electricpete]

The pump is on a rubber mat... i.e. not bolted down?

If so I would recommend to consider one aspect. There is on the discharge a force of pressure times area that will tend to push the pipe and the pump in opposite directions. The expansion joint is designed to contain the fluid pressure but not designed to restrain motion of the pump, which is a role that you may put it in if the pump is not solidly bolted down.

=====================================
Eng-tips forums: The best place on the web for engineering discussions.

 

[themroc]

thanks form the answers, the pump is not bolted down only standing on rubber mats. so maybe we need to take this into account. The thread is 1'' bsp.
What kind of bellis would be the best

 

[bingopin]

I suggest learning a little more about the vibration before trying to eliminate it. What is the predominant vibration frequency? what amplitude? Unless it is a resonance issue, decoupling the pump from the pipe might not solve your problem.

 

[quark]

Electricpete is right on. 1kW is a pretty small pump and having a rigid foundation with bolted pump should solve your problem. Many threads, in the past, indicated the uselessness of bellows for normal operating temperatures.

thread407-102681 and thread407-94199 for example.

 

[themroc]

Quark thanks for your comment I looked up the threads described, and will first go with bolting the pump down as gigit as possible. This would be also the cheapest option.