wilden pumps - air ingress potential/Nitrogen 2

[mrtangent]

Dear Sirs,

Can anyone help me here. We were planning to use a couple of wilden pumps for a particular duty. Do you know if wilden pumps can ingress air more than say a centrigal pump. In other words for the same pipework setup would a wilden due to the fact that it is air/ nitrogen driven be likely to ingress air due to seal issues etc.

Thanks in advance

James

 

[saxon]

james1030, Air operated double diaphragm pumps are as likely to have air ingression problems as centrifigal pumps in the suction lines (usually due to poor fitup in the suction piping). Also, AODD pumps are more likely to have air ingresion, if the diaphragm seals are not adequately set or there is a diaphram failure. Furthermore, Centrifigal pumps are prone to air ingression through a phenomenon know as vortexing where AODD pumps are not, but AODD pumps are prone to air ingression at the scution inlet if the liquid level drops to a point where the gas can be drawn into the inlet.

One advantage of AODD pumps over centrifigals, is that, they can can continue pumping during two phase flow events without damage. Whereas, Centrifigals will either shutdown or self destruct. Another advantage of AODD pumps is that they can be run up to dead head conditions and held there without pump damage. Not so with Centrif.

Hope this helps.
saxon

 

[Artisi]

What are you really trying to establish, you seem to have two questions in one?
1. can an AODD pump air- the answer to this is yes.
2 "due to the fact that it is air/ nitrogen driven be likely to ingress air due to seal issues etc." What are you asking here.



Naresuan University
Phitsanulok
Thailand

 

[mrtangent]

Artisi,

You are right. Two questions is what I mean.

So, because the pump is driven by air or N2 does that mean that the air or the nitrogen used to drive the pump is likely to get into the process.

So by the fact that the n2 or air drives the impeller can in get into the process.

So because you use an air driven pump are you likely to pull in air into the process due the driving mechanism.

Thanks for your responces

 

[Artisi]

The motive air / gase is isolated from pumped medium and can only enter the pumped medium if a diaphram is holed or ruptured. My suggestion is that you contact Wilden for more info.


Naresuan University
Phitsanulok
Thailand