Self-priming mechanical diaphragm pump 1

[pumpmanpl]

Hi all
i have a self-priming diaphragm pump which
is installed 4 meters above the water level
pls refer attached image...

the pump's suction is 2" and is connected
directly into a DN 150 pipe.

the DN 150 pipe drops vertically and
runs about 14 meters at a slight angle
into the water.

anyone know how to calculate the time required
to prime the diaphragm pump ie; when the air
about 1130 liters volume in the pipework
gets sucked out & the water reaches the pump's
suction inlet.

we have only being able to get the priming time
from experience with our pump operating in some
of our installations.

 

[3DDave]

It would be helpful to know the volumetric efficiency of the pump, but I would expect around 10 minutes.

Why not wait for high tide and put a check valve on the pipe?

 

[TugboatEng]

Diaphragm pumps are submersible. Priming time is a concern consider putting your pump in the tank.

 

[LittleInch]

Why don't you just have a small air valve up stream the pump to open and allow the pipe to fill under gravity for 95% of the volume unless its at low tide??

Time is also dependant on tide level as the air volume you need to move changes due to the pressure from the static head. So high tide you don't need to move out as much air. So anywhere from 6 to 10 minutes is a decent range.


Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[pierreick]

Hi,
Why not installing a foot valve ?
Pierre