staged pumps in series

[slowflow]

Reeks, you have caused me to think, thanks.
The frictional losses are greater in smaller bore resulting in degraded flow. 100 metres of 1.5 reduces flow even on the flat & HeadsUp is looking at 50-70 head which will necessitate >100 metres
Heaps to consider/contend with, the only answer I can see is to lay out the hose and measure the discharge output in one of those 55 litre buckets.
If the manufactures says 36cu/mtr no head & 27 metre max head, then @ 27 there will only be a trickle so the second pump may have to be 15-20 meters away if it can pump 12cu/mtrs. The biggest problem is manufacturers figures and the unknown element of layflat bore with its influence on flow. To be kind some manufacturers figures are overestimates.

HeadsUp will find an answer.

 

[Village]

What about if you went to a 1 inch outlet hose instead of the standard 1 1/2"?
Would the added pressure from the smaller diameter hose negate the lesser weight of water being pushed up the hose?

Hi reeks

Reackon you were on the money, thought the same, would acheive greater distance and incline, but as slow flow said, you would have reduced output at the business end. I m still there for the reverse siphon idea, it's worked for 100 years, and if it ain't broke don t fix it.

But as I opened, I had the same idea.

 

[thesmithy]

Has any one thought what firefighter do in this situation as our pumps are serious pieces of equipment.
We twin lines from the pump from a single outlet.
Reduces friction by half.

Friction loss rule of thumb 100kpa per 30m length.....300 kpa for around 100m
we are looking at 700kpa at the nozzle/branch so at 100m 700+300 plus 10kpa for every metre of rise above the pump. If say we are looking at 30m rise on the incline that is another 300kpa
so 1000 + 300 = 1300kpa this is 191psi
At the end of the hose if all is correct we still have only 700kpa. Which is what was required
$120,000.00 pump
This is using a 38mm layflat hoseSo guys all that has been discussed is all relevant if you are using a very expensive pump.

Here we are trying to push water up a hill with our pumps that are maxing out at 8psi then stalling.

20 years as a professional FireFighter I would reverse siphon (village well thought out)
only one pump needed. Minimum 5hp 50mm
Y branch out of first pump....twin 38mm for 30m no friction loss.......reverse Y branch.......single 38mm for 30m around 2.65psi friction loss not worth worrying. Now 38 to 25mm reducer 25mm hose for 30m.....12.5psi friction loss.
now at 100 m you have only lost around a very minimal amount.

if all is equal you would have minimal lift with as short a drafting hose as possible.... Zero lift preferred.

Instead of 38mm you could start with twin 50's to twin 38's to single 38's there would be very minimal loss.

My Firecrew uses this method instead of relay pumping when there is minimal crew of no extra pumpers available.
On close circuit pumping you have to have a pump operator at each pump.....for regulating over heating stalling etc.

on open circuit pumping you only need one person.

Maximum hose length 100m for relay pumping commencing with the largest pump then progressively you can use a smaller pump.

one job many years ago in the bush behind a nursing home no access to pumpers or tankers.
here is how it was staged.
street hydrant boosted into pumper.
6 x 70mm twinned by 2 up a vertical rock wall for 60m then reduced to 6 x 38mm for 100m then reduced to 38mm just twinned for 200m then on the flat 100m of single 38mm.
at this point we still had 600kpa plenty to commence FireFighting.
the 38mm then had a reverse Y breach with 1 length of 25mm on each coupling. 300kpa at each nozzle.
Plenty of pressure to do the job.
so it can be done. 500 metres up a 60m vertical cliff by reverse siphoning. This is a tried and trusted practice.
open for thought
cheers
TheSmithy.

 

[G0lddigg@]

hey Headups came across this fire hose loss calculator today bloody interesting looking at pressure drop, I had no idea reducing the hose size at the pump suffocated the PSI capabilities so significantly until comparing 50mm to 40mm lay-flat over 15 meters. Were talking 25% PSI Loss compared to 75%

anyway here's the link

http://frictionlosscalculator.com/

 

[Reeks]

Hey golddigg what sums did you put in?
I dont think 75% is accurate.
If you put the same gallon/min output in both equations that would give you false information, as the honda couldn't give you the same gal/min using a smaller hose.
Cheers
Reeko

 

[G0lddigg@]

hey Reeks right you are mate

I should have rephrased my findings and said "reduced both GPM and pressure (overall efficiency) I used the same GPM because that is the maximum the pump will put out, the pump has a rating of 110 PSI
The Friction Loss for this 49.2 foot section of 2 inch hose or pipe with 250 GPM is 24.600 PSI (pounds per square inch)
The Friction Loss for this 49.2 foot section of 1.5 inch hose or pipe with 250 GPM is 73.800 PSI (pounds per square inch)

I think what your saying is reducing a 250 GPM pump from 2" to 1.5 will also reduce GPM to 175 and using these figures will result in the following

The Friction Loss for this 49.2 foot section of 1.5 inch hose or pipe with 175 GPM is 36.16200 PSI (pounds per square inch)

 

[Reeks]

hey Reeks right you are mate

I should have rephrased my findings and said "reduced both GPM and pressure (overall efficiency) I used the same GPM because that is the maximum the pump will put out, the pump has a rating of 110 PSI
The Friction Loss for this 49.2 foot section of 2 inch hose or pipe with 250 GPM is 24.600 PSI (pounds per square inch)
The Friction Loss for this 49.2 foot section of 1.5 inch hose or pipe with 250 GPM is 73.800 PSI (pounds per square inch)

I think what your saying is reducing a 250 GPM pump from 2" to 1.5 will also reduce GPM to 175 and using these figures will result in the following

The Friction Loss for this 49.2 foot section of 1.5 inch hose or pipe with 175 GPM is 36.16200 PSI (pounds per square inch)

Think that's more likely.
Reeko