Vertical Pump Soleplate 3

[clay87]

We have an old soleplate that has corroded pretty bad and is out-of-level. Readings show about 0.020" per foot out of level. We don't have time to set a new soleplate or machine the existing one. Has anyone out there every shimmed under a vertical pump discharge head (wet pit pump) to correct for out-of-level baseplate? Any issues with this?

 

[bimr]

Why don't you grout under the soleplate. It can't take that much time.

http://cbs.grundfos.com/export/site...iles/L-CBS-WP-02_Baseplates_FINAL_Low_Res.pdf

 

[1gibson]

Will alter (lower) the natural frequency of the unit... What size pump are you talking about?

Might be a self-leveling compound you can apply to the top of the soleplate, but not aware of anything commercially available for that appliction. Some epoxy might be suitable?


Typical tolerance is not more than 0.002" / linear foot. If it is a short, enclosed impeller then you can maybe get away with worse. Long, open or semi-open impeller, you need to be pretty level or risk impeller contacting liner.

 

[clay87]

pump is 30 ft long. 3-3/16" shaft. 1250hp. enclosed impeller (has wear ring).

 

[bimr]

Your pump is too expensive to take an installation shortcut. Here is some information on leveling and grout.

http://turbolab.tamu.edu/uploads/files/papers/p23/P23Tut09.pdf

http://www.buildingsystems.basf.com...ildingsystems/products/items/docs/64p_tdg.pdf

 

[clay87]

Our guys are familiar with proper equipment setup processes but I do appreciate the useful links. We do not have time at the moment to do what you suggest. Perhaps we can plan to do it at another time.

My question is should we try to level the discharge head with shims (of course monitor vibes afterwards) or leave it out-of-level? Has anyone out there ever shimmed beneath a large vertical pump between the grouted-in baseplate and discharge head?

 

[DLite30]

Tapered shims are also an alternative.

 

[TD2K]

How long has it been like this? How long will it run like this if you do nothing? Has there been an past problems with the pump?

It doesn't sound good but if it's not creating a problem today or you have any data suggesting you are stressing the problem, you might be able not to do anything.

 

[clay87]

It's been this way a while. We just spent alot of money and effort in refurbishing this machine so it doesn't make sense to put it down on a crappy foundation (that will only get worse). We'll likely install as is for now and plan to repair the baseplate at an appropriate time. Thanks all.

 

[1gibson]

If that is your scenario, you might try the shims.

Not being level, the bottom of the pump (bowl assy) will be at a slight angle from vertical. It will want to hang straight down, so there will be some bending, and your wear rings are very likely to rub.

The concern with shims and natural frequency will cause some vibration at worst, but possibly no issues at all. I'd take that over an almost guaranteed wear ring rub on a fresh refurb.

Of course, neither is ideal, but if we only went with ideal, we wouldn't get a whole lot accomplished.

 

[Artisi]

If its a 30ft long pump and not hanging vertically, the wear, if any will be on the line-shaft and bearings (this is assuming it has either bronze or similar or cutless rubber bearings for shaft support). Do not see any reason for wear-ring rub as the pump shaft would or should be well supported in this area.
There are many "vertical" pumps installed throughout the world in sloping installations and provided the pump is properly supported so as the pump column is straight where is no problem with shaft deflections, or casing / impeller rubbing.

The original question was about shimming under discharge head to bring the pump back to vertical but without more information ie, drawing or photo there is really no definite answer although this is or could be normal practice in many installations.

So, lets see a photo / drawing / sketch and then maybe you will get a meaningful answer.

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.)

 

[diverdan8]

Clay87, I have used shims under heads for over 30 years to level it, the trick is to assure you have enough support around the whole base of the head to support it, in some cases shims are only added to the corners of the head, this puts to much pressure at the unsupported areas of the head and it cracks, especially on cast iron heads.
If you place supports under the whole base of the head you should have no proplems.

 

[nfinit]

the typical statement is do it right or do it again. Since you are in a bind and it appears your only choice is shimming until you can plan the proper repair (which may plan itself) I suggest using as few shims as possible, keep it under 3. Just my rule of thumb.