Vertical Turbine Pumps

[diverdan8]

Anyone famililar with Vertical turbine water flush application with an enclosing tube?
I am trying to get information as to the design and operation.
I am familiar with Oil lube, however I was told I needed S.S. lineshaft for water-flush (which seems reasonable) and that I will need pressurized water into the tension bearing for lubrication. What kind of pressure at what volume?

 

[Artisi]

are you sure it is enclosed, usually water lube is open and uses the pumped water for lubrication.

Why not ask the pump supplier / manufacturer ??? for their guidance .

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.)

 

[eyec]

google "John Crane Mechanical Seal Piping Plans Companion Booklet"

API 682/ISO 21049 standards have default (required) connections and connection symbols for seal chamber and gland plate connections based upon the seal configuration.

 

[JJPellin]

I have never heard of an enclosed line-shaft for this service. Artisi is correct. It would normally be an open shaft. It might be lubricated with the pumped water or with an outside source of clean water. But, the clean water flush to the line-shaft bearings would normally be piped from the surface to each individual bearing. Making this an enclosed line-shaft adds cost and complexity that would not normally be justified.

Johnny Pellin

 

[Artisi]

Johnny, enclosed water lube is possible and is used in some isolated cases but very unusual. If using fluted "cutless rubber" lineshaft bearings it would be the norm to used the pumped water for lube but as you say, an external source piped to each bearing is possible and would only be used in isolated cases which warrant the added expense and complexity. It could / would be found on lineshaft pumps with very long drive lines which require pre-lub. on start-up.

The info given by the OP at this stage is too limited to make any meaningful recommendations

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.)

 

[TenPenny]

We have a customer with a few of these, they're used in pulp mill effluent service, where the water has fibers, sand, knots, etc in it and isn't suitable for flushing, so an external source of water is used to flush the bearings.

If memory serves, the shaft is 416ss, and the bearings are bronze.

I don't know if I have any info on required flush volume/pressure, I'll see what I can find. After some more coffee.

 

[diverdan8]

It is enclosed tube, water lube open line shaft is only good to about 200' settiings with a pre-lube,this is setting 460', so because of the oil contamination issues (even with vegtable oil) more people are turning to enclosed tube water flush systems, where water is used to lubricate the bronze bearings, I am just trying to find out the correct lubricating procedures for such a system as water does not have the same viscosity as oil, so I am not sure of the correct precedure.

 

[diverdan8]

TenPenny,
Thank you an information you may have would be great.

 

[JJPellin]

We have a number of deep well water pumps that are over 500 feet with open line shafts and cut-less rubber bushings. We run lube water down the well for 15 minutes before start-up to wet the bushings. Our wells tend to run 24/7 and rarely shut down. So, we don't get many starts. These pumps typically run 4 or 5 years between overhauls. If industry is turning to enclosed shafts for these applications, I am not looking forward to that change. I am sorry. I have no information on the pressures and volumes required to lube this arrangement. If I am ever forced to purchase one, I will rely on the manufacturer for these details.

Johnny Pellin

 

[Artisi]

Johnny, I agree - to use enclosed water lubricated bronze bearings would warrant a very special case with pump length not being one of them.

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.)

 

[clay87]

what is pump length? For our vertical turbine pit pumps 20-40 feet long we use 20-40psi to the stuffing box/tension device. For a 3" shaft, we see about 5-8 gpm. Our shafts are typically SS (or 17-4PH or XM19) but our service is raw water that could be salty/brackish.

If your pump discharge pressure is greater than the enclosing tube pressure (likely) you may need:
* a throttle bushing and flush ports to discharge the flush water into the pit/well (this keeps pumped product from entering enclosing tube) OR
* a balanced impeller (for single stage) so that flush water can discharge into the pump on the backside of the impeller OR
* some other way to discharge the flush water

If you have a tail bearing, you may need some tubing or a rifle-drilled shaft to provide water flush.

For operation: I recommend flush water flow meters and pressure gauges. Obviously establish flush water flow before starting pump.

 

[diverdan8]

Thank you all for your input, the truth be told I work for a major pump manufacture and I sell V.T. pumps as well as others, I will not mention the company as I am not trying to push any thing here.
The fact is that Water-Flush enclosed tube applications are becomming more in use because of contamination issues with the oil in contact with water.
JJ, I am surprised that you set open lineshafts water lube V.T as deep as you do, I would not reccomend it past 200' because of the pre-lube issues, however if you pre-lube for 15 mins. before you start it must be O.K. however most people would not have that kind of dedication and I would be replacing pumps left and right.
I was trying to get feed back on other types of systems out there.
Typically a water-flush V.T deepwell pump uses the same equipment as oil lube except the lineshaft is S.S. instead of 1045 and the bearing grooves are bord a little deeper to allow water to flow more freely from .125” to .188” deep grooves cut. Also water should be injetted into the tube through the existing tension bearing at a pressure of 10-15psi.
This is the system we are currently using.
Thank you