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Suction Dampener of mud pumps
09 July 2020
Hello dear members,

I hope you are in the best of health.

I would like to know your thoughts on the suction  dampener of mud pumps.  The suction dampener in the mud pumps that I deal with is pressurised up to 25psi (based on manufacturer’s recommendation).  It is quite a low pressure and most of the time it is either taken out of the pump or not even pressurized. Since it is in the suction side of the pump, that should mean it will serve a dampening role to the feed pump (centrifugal pumps) .

I would like to know what is the main reason of placing dampener in the suction side of the pump? and does it really matter? If so, why I do not see any difference in pump  behaviour when the dampener is not charged?

This might sound a silly question for you  members, and I don't want to annoy you, but I have asked many people and done quite a lot of research, and yet I didn't get a reasonable answer.

That led me to drop this question here because I know here is the perfect place to ask.

Warm regards.

_________

Note from moderator (Dave):

Please bear with Montader.  I've had recent feedback that some of the questions on SPREAD can be a bit 'basic', but here we have an aspiring future mentor asking our help.  The answers won't just help him.
10 answer(s)
Alsuhail
Rig_site Engineer
IDC
Total Posts: 15
Join Date: 24/06/20
appreciate you all gentlemen for taking the time and being supportive 
SCollard
Consultant Well Engineer and Trainer - HPHT, Deepwater and MPD Well Delivery and Well Control,
Welltrain Limited
Total Posts: 25
Join Date: 09/12/09
Pete ...good find!!  Thanks for sharing.

Steve
Companyrep
Drilling Specialist/Well Engineer/Training Consultant
Kingdom Drilling
Total Posts: 471
Join Date: 10/01/05
As Steve Stated its to elimate 'pump chatter' on the suction valve  side, smoother performance and likely prolongs suction valve life.

You don't see them on all rigs or pumps. I suspect because it depends on how your hooked up to your suction mud pits.

Particularly on land rigs the distance from the suction pits to the mud pumps is very short with the charge pump in the middle. The fluid head on the suction side may provide the suction dampening needed and why a suction dampener is not needed in such cases.
(not exactly sure about this still seeking the evidence support document needed as to why and why not)

I did find a useful file on 'looking after and optimizing your mud pumps' that i have shared and attached.
Scott_McNeil
Consultant
SPREAD Associates
Total Posts: 153
Join Date: 05/03/08
Hi Montader,

See? Thanks to Steve Collards response, I learned something new today.

So never be afraid to ask a 'stupid' question!

All the best!

Scott
ericvillepreux
Fluids and Cement Superintendent
Assala Energy
Total Posts: 14
Join Date: 19/10/14
Hello Montader,

As mentioned in the previous answers, no need for a suction stabilizer if your rig pumps are feed using a supercharging centrifugal pump.

Suction stabilizerq are mainly used to feed diaphragm pumps where they  act as accumulators and reduce pressure fluctuations that can increase diaphragm and valve wear.

Use of suction stabilizers will increase the NPSH value, which will decrease the energy required to draw fluid into the pump.

Stay safe,
Eric


SCollard
Consultant Well Engineer and Trainer - HPHT, Deepwater and MPD Well Delivery and Well Control,
Welltrain Limited
Total Posts: 25
Join Date: 09/12/09
Montader,   as others have said ..there is no such thing as a silly question!  
You are absolutely right about the centrifugal pump providing a smooth flow to the pump.  This is actually the reason for the suction dampener - the triplex pump action doesn't actually take a smooth flow because the pistons are constantly moving back and forward and stopping.  The dampener helps to deal with these small changes in flow. 
I was able to find a great little video on You-Tube about the suction side dampener.   You can find it here:
https://www.youtube.com/watch?v=YkH9QNgUYKg

The video starts with a review of events leading to a fatality when HP nitrogen was used to recharge the bladder in a suction dampener. 
The explanation on the use of the dampener starts at about 4:00 minutes into the video.
If your pump is fitted with a suction dampener it should really be in use and correctly charged.  
Best wishes,  Steve
Alsuhail
Rig_site Engineer
IDC
Total Posts: 15
Join Date: 24/06/20
dear Mr. Scott
as far as i know and as you have mentioned that centrifugal pumps provide a continuous smooth stream of flow unlike reciprocating pumps which the flow would be like a pulse. 
in fact the distance between the mud tanks and our triplex pumps is approximately 2.5m.
thank you again Sir.
Alsuhail
Rig_site Engineer
IDC
Total Posts: 15
Join Date: 24/06/20
thanks dear Ahmed and Mr Scott for your comments
Scott_McNeil
Consultant
SPREAD Associates
Total Posts: 153
Join Date: 05/03/08
Hi Montader,

Firstly, there is no such thing as a silly question! I'm sure I'm not the only 'grey hair' who has been asked a 'silly question' by a young engineer in the past - only to not know the answer ourselves!

Anyway, I honestly cannot recall any rig I've worked with that has had a pulsation dampener on the suction side of the pump.

A centrifugal pump by the nature of the way it operates should provide a steady flow anyway, so I do not see how installing a dampener in the suction line would help smooth it out further.

The only case I can think of for needing one is if there is - for some reason - a large horizontal and/or vertical distance between the mud tanks and the mud pumps, so you'd have to use a positive displacement pump instead of a centrifugal pump as a primer.

Keep asking questions!

All the best!

Scott
ahmedix
Consultant
SPREAD Associates
Total Posts: 15
Join Date: 26/09/13
My thoughts are that on modern day rigs the centrifugal changing pump are driven by electric motors, however in the past they were driven by other prime- movers such as a Diesel engines, connecting to another moving system on the rig or even steam engines, in which case the damper played a positive role. Weather a suction has a dampener or not, a pressure relieve valve or check valve should be placed between the mud pump and the charging pump, because pressure from the mud pump(s) leak back, the centrifugal will blow-up and can cause significant damage.
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