Strainers Location

[sowhatso]

Two water wells are discharging water using submersible pumps for Balancing tank No. 1 and then booster pumps are used to discharge the water to Balancing tank No. 2 , after that OTHER booster pumps are used to discharge water from BT.2 to the main reservoir ,

I need to install clean in place basket strainers , TO keep the tank clean and free of large debris that could damage the horizontal pumps and the control valves AT both booster stations.

I need to know from your experience , what is the best and the most recommended locations for the strainers to be installed ? at the discharge lines of both wells (On the wellhead)? or at the inlet lines of the booster stations ? or any other places ???

Some people did not recommend to install strainers due to the high friction losses and also they consider the tank is working like strainers as the suction elbows inside tank is above the floor slab and drainage line can be used to clean the tanks frequently !!!

any inputs are highly appreciated.

Thanks

 

[gr2vessels]

An API 650 tank with cone down bottom, fitted with a central pit and drain pipe under floor should do the trick.
howzat,
cheers,
gr2vessels

 

[sowhatso]

All the balancing tank that are used for the project are of Concrete .

 

[Unotec]

If you don't mind debris in the balancing tanks I'd install the strainers after these tanks.

 

[Artisi]

If your pumping from wells with submersible pumps, where will the large debris come from? Seems to me you are creating a problem over nothing.

 

[hbw]

Consider Johnson Well Screens. These are used on raw water intakes for power plants. Screens are T shaped and installed parallel to stream lines. Redundant screens and suction lines are installed to allow one to be cleaned while others are in service. Cleaning is by reversing water flow direction. Screens are available in a variety of opening sizes.

 

[RossABQ]

If your only concern is the pumps, most horizontal pumps can handle 2" - 3" solids without any problem. Like Artisi, I'm not sure why you would expect debris from a well, that could plug a pump? You don't state the flow rates, but if these are large pumps you will not want a fine mesh strainer that captures sand ahead of the pumps.

To protect the control valves, small strainers with 1/16" mesh screens would do the trick.

 

[sowhatso]

Thanks alot for all the inputs , I'm planning to install the strainers at the suction line of the booster pumps , the location will be directly before the suction nozzle of the pump , will this close distance of the strainer from the pump suction create any turbulance of flow ?

 

[Artisi]

Where are the expected solids coming from - out of the well ?????????????

 

[sowhatso]

Artisi ,

This is My expectation :

The steel pipelines from the wells to the booster stations and between the booster stations were welded by complete joint penetration (CJP),after welding ,repairing were done for all locations of welding joints inside the pipes where the cement lining was chipped off to allow for CJP, the repairing process was not done perfectly as it was ver hard to go through the small diameter pipes and to apply the cement at the internal locations. I expect that all cement used for repairing will peel off and damaged during the discharge of water with the high working pressure and due to the surge back pressure ( about 45 bar) !!!!

Artisi , this is the main source of solids ,from your professional experience if you think that cement lining will not cause any damage to the booster pumps , I will not install the strainers ????? !!!

Thanks

 

[Artisi]

Now that we understand where the solids are coming and the nature of the solids it is a new ball game.
My understanding from your first post is that you are discharging into holding tanks prior to further pumping - if this is the case isn't it sufficient to have the inlet to the booster pumps positioned in such a way that any solids are retained in the holding tanks either by locating the inlets above the lower level of the tanks or by placing a trash screen / strainer within the tanks as you are now suggesting. If the strainers do not impose any significant head loss and are positioned in the tanks a resonable distance from the pump inlets there shouldn't be any problems with turbulance.

An alternate suggestion is to include a weir with in the tank/s after the inlet and well away from the outlet (inlet to your pumps)

 

[sowhatso]

Thanks alot Artisi