vibrating line - cause ?

[plumberet]

Like to know how to differenciate between vibrating line due to hammering and cavitation. Line is for transporting water at about 110 C through a control valve.

I thought for hammering, one needs a change in the flow, e.g. closing a valve. The vibration is continuous and not intermittent. Think it is due to cavitation than hammering. Your thought ?

 

[chief]

Would appear that you have steam bubbles traveling along your pipe,which are compressing and expanding intermittently.
You could fit a high point vent and /or a pressure damper vessel to reduce the vibration.

Offshore Engineering&Design

 

[katmar]

If you are passing water at 110[°]C through a control valve it is very likely that you will have cavitation. What are the pressures each side of the valve?

Katmar Software
Engineering & Risk Analysis Software

http://katmarsoftware.com

 

[Artisi]

New or old problem?

Besides the info already supplied, it could be vane pass frequency, out of balance impeller, mis-alignment of pump / motor, pump or motor loose on it's baseplate, cavitation at the impeller inlet.

 

[HEC]

Plumberet
From the questions and comments to date there is insufficient information in the OP. Can youn provide more information. Where is the hot water comming from, what is the line pressure up/down from the valve, what is the system the hot water is in? If you want quality answers we need all the information.

Mark Hutton

 

[Artisi]

To answer your original question asking who to tell the difference between cavitaion and "hammering" (whatever that is)- a full vibration analysis should differentiate between cavitation and "hammering" or some of the other likely causes that lead to vibration.

 

[Artisi]

Please read who as how in my earlier post :-

 

[plumberet]

Sorry, more infor as below.
Water is from a scrubbing unit and pressure at about 15 barg. About 10 barg after the control valve. Temp at about 110 C. Pump is upstream of the scrubbing unit. Vibrating line is after the scrubbing unit.

 

[HEC]

By scrubbing unit I am presuming it is a unit where the high pressure hot water is sprayed into a gas stream to remove (something). The control valve after the scrubber controls the water level in the sump. On this basis it would appear that there is some entrained gas in the hot water drained from the scrubber. This is either causing bubbles that are expanding and collapsing or comming out of solution after the control valve.
Back to Artisi's question is it a new or old problem, has something changes to create the problem?


Mark Hutton