Turbine pump discharge head connection ?

[Nordic119]

Hi
We have an existing 12" well casing that sticks out of the ground about 10' when they installed it. During the wet months, the well is artesian & under about 5-7 lbs of pressure.

We were wanting to mount a vertical turbine pump, with a linehshaft, column & bowls down into the well...inside the casing (down to about 60'). We were going to pour a raised pad (24"x24"x12") at grade, & mount a surface discharge head with a flanged connection to the column & a sole plate over the pad.

My question is, can we just cut the well casing just below the top of the pad? If so, will the base of the discharge head & sole plats seal the well casing from leaking when the well is artesian? Or do we somehow have to put an flanged adapter on the well casing after we cut it & mount it to the discharge head somehow (in addition to mounting it to the column)?

Thanks.

 

[bimr]

You should check with the authority in your area to make sure that your well construction meets the local law.

Generally, an approved well cap or seal shall be installed at the top of the well casing to prevent any contamination from entering the well through the top. This will typically bring the top of the casing 8-inches above grade.

http://www.idph.state.il.us/envhealth/factsheets/drilledwlsFS.htm

If you are asking if you can cut the well casing below grade, attach the pumpg flange to the concrete, and then use the concrete pad to seal the well, the answer is no.

You should also check the local requirements regarding protection of the well from flooding.

 

[SteveWag]

If you are using water lubricated bearings, the discharge head can be sealed, and normally is. Some manufacturers offer vertical turbines for “canned pump” installations, having a standard flange drilling (and pressure rating) as a mounting base. Using one configured like that, you can cut the casing, weld a flange, and set/connect the pump. The concrete pad is actually optional. It is always nice to be able to access the underside of the flange in order to get to the bolts/nuts. Using a standard flange pattern allows the use of off the shelf gaskets.

Look at page 9, type “L” for an example. The only difference is that your inlet is from the aquifer below.

http://www.christensenpumps.com/pdf/verticle_turbine_brochure.pdf

Your “can” is the well casing.

The casing is normally capable of taking the weight of the pump and the bigger number, the hydraulic downward thrust.

I would not trust a flanged adapter, or the ability of the concrete to seal the installation.
Steve