Sometimes, a good solution can be splitting the outflow at your pump into two lines that lay side by side. Maybe one of those lines jumps into an underground pipeline and it's sister line continues to run above ground. Then, they meet at the center pivot and join into another pump. Perhaps that pump is ready to push through the last few pieces of drags to the tractor, the process is repeated with another set of twin line, or they merge through a single hose for a shorter distance.
The idea is to decrease friction losses by allowing each hose to flow half of our total flow rate.
Let's say you have a pump unit at the manure storage site that will flow 1750 GPM. Perhaps it's a PCE PT 2047 with a 4NHTB Cornell Pump and a 275 horsepower JD 6.8 L engine. This works with any pump, just be sure to consult your pump curve.
If we take a look at the pump curve, we can follow the CAPACITY across the bottom to 1750 GPM - that's our goal. On the left vertical axis, find 2000 RPM at the top. Follow that dark black line over to where it meets 1750 gallons per minute (GPM). This just over the 250 horsepower requirement, noted on the right side of the chart by the slashed line traveling diagonally up and to the left. Along the top of the chart 20 FT is noted as NPSH REQUIRED. The pump will require close to 21 FEET of head coming into the pump to operate correctly at this flow.
The chart shows with all these requirements filled, the pump will produce about 400 FEET of Total Dynamic Head (TDH). 400 divided by 2.31 equals 173 PSI.
If we split the 1750 gallon per minute outflow into 2 lines each flowing 875 gpm, lets see how far we can go compared to a single line flowing the full 1750 gpm.
Single 8 inch line @ 1750 = 23.5 feet of head loss per 660 ft. length
400/23.5 = 17 lengths of distance
Single 7 inch line @ 1750 = 45 feet of head loss per 660 ft. length
400/45 = 8.88 lengths of distance
Single 6 inch line @ 1750 = 95 feet of head loss per 660 ft. length
400/95 = 4.21 lengths of distance
Single 5 inch line @ 1750 = 232 feet of head loss per 660 ft. length
400/232 = 1.72 lengths of distance
(8 lengths per mile, or 200 meter lengths)
Twin 8 inch line @ 875 gpm each = 6.5 feet of head loss per length
400/6.5 = 61.5 lengths /2 = 30.7 lengths for each line
divided by 8 = 3.8 miles (compared to 2.125 miles solo with the same pump at the same flow rate)
Twin 7 inch line @ 875 gpm each = 12.5 feet of head loss per length
400/12.5 = 32 lengths /2 = 16 lengths for each line
divided by 8 = 2 miles (compared to 1.1 miles with a solo line at the same flow with the same pump)
Twin 6 inch line @ 875 gpm each = 26.5 feet of head loss per length
400/26.5 = 15 lengths /2 = 7.5 lengths for each line
divided by 8 = 0.94 miles (compared to 0.52 miles with a solo 6 inch hose)
Twin 5 inch line @ 875 gpm each = 64.3 feet of head loss per length
400/64.3 = 6 lengths /2 = 3 lengths for each line
divided by 8 = 0.375 miles
In conclusion, a twin line can help you maximize the ability of a single pump to reach it's best gallons and best distance.
If we take a look at the pump curve, we can follow the CAPACITY across the bottom to 1750 GPM - that's our goal. On the left vertical axis, find 2000 RPM at the top. Follow that dark black line over to where it meets 1750 gallons per minute (GPM). This just over the 250 horsepower requirement, noted on the right side of the chart by the slashed line traveling diagonally up and to the left. Along the top of the chart 20 FT is noted as NPSH REQUIRED. The pump will require close to 21 FEET of head coming into the pump to operate correctly at this flow.
The chart shows with all these requirements filled, the pump will produce about 400 FEET of Total Dynamic Head (TDH). 400 divided by 2.31 equals 173 PSI.
If we split the 1750 gallon per minute outflow into 2 lines each flowing 875 gpm, lets see how far we can go compared to a single line flowing the full 1750 gpm.
Single 8 inch line @ 1750 = 23.5 feet of head loss per 660 ft. length
400/23.5 = 17 lengths of distance
Single 7 inch line @ 1750 = 45 feet of head loss per 660 ft. length
400/45 = 8.88 lengths of distance
Single 6 inch line @ 1750 = 95 feet of head loss per 660 ft. length
400/95 = 4.21 lengths of distance
Single 5 inch line @ 1750 = 232 feet of head loss per 660 ft. length
400/232 = 1.72 lengths of distance
(8 lengths per mile, or 200 meter lengths)
Twin 8 inch line @ 875 gpm each = 6.5 feet of head loss per length
400/6.5 = 61.5 lengths /2 = 30.7 lengths for each line
divided by 8 = 3.8 miles (compared to 2.125 miles solo with the same pump at the same flow rate)
Twin 7 inch line @ 875 gpm each = 12.5 feet of head loss per length
400/12.5 = 32 lengths /2 = 16 lengths for each line
divided by 8 = 2 miles (compared to 1.1 miles with a solo line at the same flow with the same pump)
Twin 6 inch line @ 875 gpm each = 26.5 feet of head loss per length
400/26.5 = 15 lengths /2 = 7.5 lengths for each line
divided by 8 = 0.94 miles (compared to 0.52 miles with a solo 6 inch hose)
Twin 5 inch line @ 875 gpm each = 64.3 feet of head loss per length
400/64.3 = 6 lengths /2 = 3 lengths for each line
divided by 8 = 0.375 miles
In conclusion, a twin line can help you maximize the ability of a single pump to reach it's best gallons and best distance.
These numbers are based on cool water. They do not take into account elevation changes, requirements of the next pump in line, variations in temperature or changes in direction. This is just a guideline to show how a single scenario would work in theory.
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