troubleshooting a vertical multi-stage pump
troubleshooting a vertical multi-stage pump
(OP)
thread407-263167: troubleshooting a vertical multi-stage pump
Hi I have recently installed a newly recondition drive motor of a Floway pump. the problem is during testing the pump is operating in low pressure. we only tested it for a little while because we could not see any immediate change in pressure gauge that would detect whether there is flow.
as I was reading on installation guide of possible cause of low pressure, it mentioned that there is a possible reason that the cause of low pressure is air.
I was thinking that since we did not test it longer maybe air is present on the pipe line that is why the pump is not delivering well, should we have tested it longer to eliminate this? or could anyone tell me how to commission an installed pump.
Hi I have recently installed a newly recondition drive motor of a Floway pump. the problem is during testing the pump is operating in low pressure. we only tested it for a little while because we could not see any immediate change in pressure gauge that would detect whether there is flow.
as I was reading on installation guide of possible cause of low pressure, it mentioned that there is a possible reason that the cause of low pressure is air.
I was thinking that since we did not test it longer maybe air is present on the pipe line that is why the pump is not delivering well, should we have tested it longer to eliminate this? or could anyone tell me how to commission an installed pump.





RE: troubleshooting a vertical multi-stage pump
Is the motor running in the correct direction? - (yes I know, of course it's running in the right direction) - go and check it yourself.
It is a vertical turbine pump- where do you think the air is?
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: troubleshooting a vertical multi-stage pump
Johnny Pellin
RE: troubleshooting a vertical multi-stage pump
RE: troubleshooting a vertical multi-stage pump
Is the motor running in the correct direction? - (yes I know, of course it's running in the right direction) - go and check it yourself.
It is a vertical turbine pump- where do you think the air is?"
----The thing is they had this pump drive motor recondition because they said that they were experiencing noise and vibration during operation. what they are not certain is if the pump's pressure before re-con was okay because their pressure gauge which is used to determine flow was not functioning.
Is the motor running in the correct direction? - (yes I know, of course it's running in the right direction) - go and check it yourself.
It is a vertical turbine pump- where do you think the air is?
----well during testing there was water coming out of the discharge so that is my basis that it is running in the right direction.
or is it possible that it could still be running in wrong direction even if there is water discharge?
RE: troubleshooting a vertical multi-stage pump
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: troubleshooting a vertical multi-stage pump
Was the pump worked on at all??
Was the impeller clearance reset after reinstalling motor?? (if open impellers)
Are they keyed or colleted impellers ??
If running backwards is not the problem, answer these questions.
RE: troubleshooting a vertical multi-stage pump
Okay so air is not possible, I'm sure that the rotation is correct, Im drawing a conclusion here that we might have loosen one or more of its impeller due to handling. Now how do I check for that?
RE: troubleshooting a vertical multi-stage pump
There are two types of wear surfaces on impellers of this type. Some use conventional radial wear rings. For these, the impeller lift is not as critical. It needs to be enough that the impellers don't rub. The second type uses a lateral wear surface that seals axially off the end of the impeller eye. For these, the lift is much less and much more critical. If it has a lateral wear ring and was set with excessive lift, it may not build proper pressure. Some pumps have both radial and lateral wear surfaces.
Our crystal balls are getting fuzzy. We can keep guessing for a bit longer. Then we are likely to get bored and drift away without more details.
Johnny Pellin
RE: troubleshooting a vertical multi-stage pump
Johnny Pellin
RE: troubleshooting a vertical multi-stage pump
I am ASSUMING this is a run of the mill, cast iron/bronze fitted, open lineshaft, colleted, open impellers, typical Floway VTP.
You won't be able to do much without pulling the pump again. If rotation is correct, my next guess would be the collets are no longer securing impellers causing them to slip on the pumpshaft.
If impeller blades are badly worn or deformed, and clearance was not set properly while fumbling with the coupling, this could cause low flow.
You say the unit was vibrating w/ noise prior; why was it assumed it was the motor?
What kind of difficulty did you have with the coupling?
Just swingin' in the dark here.
RE: troubleshooting a vertical multi-stage pump
The problem with vertical turbine pumps, unlike dry pit pumps, is that becasue the pump is in the water you cannot hear if there is any problems. Cost trade off issue
RE: troubleshooting a vertical multi-stage pump
Was the pump operating ok prior to maintanace in terms of hydraulic performance?
Plus we are all assuming that there is actualy water present to be pumped.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: troubleshooting a vertical multi-stage pump
It is a non potable pump with a drive motor of 7.5hp 3540rpm
Model no. 5K213DTP5014. Brand floway
As I remember it is an 8 stages pump but im not really sure.
Out side casing of impellers are very similar to the characteristic of a carbon.
I will try to attach the photo as soon as I get to my laptop.
They assumed it was the motor because, the unit has not been reconditioned for 9 years so the assumed that it might be the motor bearing.
We had trouble installing back the coupling due to damaged thread of the shaft.
They are not sure if it was operating well prior recondition because their pressure gauge which is their basis if pressure of pump is okay was not working.
We will try to pull the unit this week to check. I shall keep you guys posted.
RE: troubleshooting a vertical multi-stage pump
Guess we are all now waiting to see the outcome of the investigation.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: troubleshooting a vertical multi-stage pump
above is the photo of the pump.
RE: troubleshooting a vertical multi-stage pump
RE: troubleshooting a vertical multi-stage pump
- I will let you know once we get a chance to pull out the unit and dismantle.
RE: troubleshooting a vertical multi-stage pump
I'm really new to my work and I don't trust our technicians so much regarding this type.
RE: troubleshooting a vertical multi-stage pump
They may be more expensive than the pump is worth and you may not want to use them, but at least asking that way will get you some info. Look for Walter Lee's name; he is a big shot with the vertical group in Fresno; but is a very good guy and will forward your info to the right person.
RE: troubleshooting a vertical multi-stage pump
12 Mar 13 21:51
Before your "technicians" put chain tongs and cheater pipes on the pump, give Weir a call (or email). It looks like the pump Serial# you gave above; just send it along with basic questions, a request for a manual, or a Weir certified shop (most likely their Distributor) in your area.
They may be more expensive than the pump is worth and you may not want to use them, but at least asking that way will get you some info. Look for Walter Lee's name; he is a big shot with the vertical group in Fresno; but is a very good guy and will forward your info to the right person.
-----Actually I checked Weir website and they do not have a local service center available here in the Philippines and I tried googling for a distributor, unfortunately the listed company I found on google does not pick up their phone anymore.
Do you happen to know which department Walter Lee is under, I think my last shot for guidance is by calling fresco office once I get more information regarding this pump.
-Thank you everyone for the help.
RE: troubleshooting a vertical multi-stage pump
Weir Minerals Australia Ltd | 1 Marden Street, Artarmon NSW 2064
T +61 (0)2 9934 5100 F +61 (0)2 9934 5201
australiansales@weirminerals.com
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: troubleshooting a vertical multi-stage pump
walter.lee@wierminerals.com If he doesn't help you, tell him you know somebody in Houston that will personally come and kick his skinny butt.
RE: troubleshooting a vertical multi-stage pump