Parallel Pumping - Irrigation

[Formaleins]

Wondered if anyone had any experience with this, combining two separate pumps pumping from two separate wells and combining the flow to increase the water pressure for irrigation.

 

I am planning to join (again - first attempt was a failure due to flow direction) two electric water pumps, they are I believe about 1/4 HP and pump 350 litres per minute via a 2" inlet / outlet.

 

The pumps are 50' apart and feed 7 outlets each individually valved. They feed an irrigation system that consists of (Each outlet is identical) 75m of 2" piping joined to 75m of 1.5" piping connected lastly to about 50 metres of 1" piping, they are pretty much evenly spaced at 4m intervals with a 3/4" feed to the trees.

 

I ran two pumps in parallel twice before, the first time was successful but the second time was a disaster.

 

First time the pumps were 50M apart feeding into 2"pipes pumping in the same direction. 2nd time they were closer together, maybe 20M and opposing each other - it didn't work.

 

My idea this time is to either connect them at 90 degrees about 50'apart but both pumping in the same direction, or my second option would be to connect them via a "Y" type pipe, again in the same direction.

 

Anyone done this before and managed to boost the pressure?

 

Personally, I think the Y junction would improve the flow, but then again I was wrong before so......

 

In the second sketch you can see that the problem might be with the first row as both pumps are actually pumping in the wrong direction of flow and would need to actually pump back from the Y joint 180 degrees.

Edited February 22, 2017 by Formaleins

[grollies]

Joining the two pumps in a Y piece will not boost pressure. A Y is the best way to join the two pumps but...

 

Each pump discharges around 350l/m into a single 2" pipe. That is 21m3/hr per pump. With a low pressure (0.25hp) pump you are unlikely to achieve any more flow than that supplied from the first pump through 2" pipe at low pressure by adding the second pump.

 

In order to achieve a higher pressure you should try putting the pumps in series, i.e. putting the 2" discharge from pump 1 into the suction of pump 2. This will increase the discharge pressure from pump 2.

 

Put a pressure gauge in line and ensure you don't overpressurize pump 2 pumphead.

 

Otherwise it's a 2 stage pump you need with a higher hp.

Edited February 22, 2017 by grollies

[Formaleins]

54 minutes ago, grollies said:

Joining the two pumps in a Y piece will not boost pressure. A Y is the best way to join the two pumps but...

 

Each pump discharges around 350l/m into a single 2" pipe. That is 21m3/hr per pump. With a low pressure (0.25hp) pump you are unlikely to achieve any more flow than that supplied from the first pump through 2" pipe at low pressure by adding the second pump.

 

In order to achieve a higher pressure you should try putting the pumps in series, i.e. putting the 2" discharge from pump 1 into the suction of pump 2. This will increase the discharge pressure from pump 2.

 

Put a pressure gauge in line and ensure you don't overpressurize pump 2 pumphead.

 

Otherwise it's a 2 stage pump you need with a higher hp.

Thanks,

something to consider. Appreciate the feedback I just need to get enough pressure 200 metres upstream to blast all of the crap that has decided to make my pipes their home, sadly, one pump won't do it anymore so I am going for two. I had read online that two pumps in parallel were more efficient and could generate more pressure, ( Pressure is what I need rather than volume)

Edited February 22, 2017 by Formaleins

[grollies]

4 minutes ago, Formaleins said:

Thanks,

something to consider. Appreciate the feedback I just need to get enough pressure 200 metres upstream to blast all of the crap that has decided to make my pipes their home, sadly, one pump won't do it anymore so I am going for two.

Pig the to clean the pipes, similar to this link.

 

I pig all my irrigation pipes from time to time.

 

You want any further help cleaning PM me.

 

 

[grollies]

10 hours ago, Formaleins said:

I had read online that two pumps in parallel were more efficient and could generate more pressure, ( Pressure is what I need rather than volume)

Nope, pumps in parallel will increase volume not pressure provided the pipe on the pumps discharge is of a large-enough diameter to avoid friction loss.