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How to calculate the power and the drive torque of your pump?

ImperialMetric system

1. Determining power 1. Determining power

1.1. Hydraulic power 1.1. Hydraulic power

Hydraulic power is obtained from the following equation: Hydraulic power is obtained from the following equation: hyd HPGPMPSI =useful HPhyd HP0.7------------------= hyd HP1231

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11714 =useful HPhyd HP0.7------------------= hyd HP4510 QP 1.67

1. 2. Drive power 1. 2. Drive power

The mechanical power that must be supplied to the pump will always be 15 to 30% (depending on pump ty- pe The mechanical power that must be supplied to the pump will always be 15 to 30% (depending on pump ty- pe
(1) ) greater than the hydraulic power of the pump.
(1) ) greater than the hydraulic power of the pump.

1. 3. Practical example 1. 3. Practical example

A PB 33 pump (0.00274cu.in) is driven at 4000rpm and is required to provide maximum output pressure of 4350PSI. What is the power necessary of the motor driving the pump ? A PB 33 pump (45mm
3 ) is driven at 4000rpm and is re-quired to provide maximum output pressure of 300bar. What is the power necessary of the motor driving the pump ? = useful HPD10 QP 1.67 =hyd HP90
6– = useful HP1231 GPMPSI

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11714 4000 3001.67 =hyd HP0.120 HP=useful HP0.1200 =useful HP900.7-------130 W

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0.002744000 435011714

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=hyd HP W =hyd HP from 100bar
(2) to maximum pump pressure, the requi-red installed power will be virtually proportionnal to

.

7-------------0.172 HP P . from 1450PSI
(2) to maximum pump pressure, the re-quired installed power will be virtually proportionnal to P . from 800
(3) to 6000rpm, the required installed power will be virtually proportional to N . from 11603PSI
(3) to 6000rpm, the required installed power will be virtually proportional to N .

1. 4. Quick calculation formula

17

1. 4. Quick calculation formula

=
6– N P 1.6710.7

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=useful HP

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D N PSI

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11714

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10.7 =useful HPD10
6– N P 2.4 =hyd TD DN PSI 3.608.10
-6

2. Determining torque 2. Determining torque

2. 1. Theoretical torque2. 2. Drive torque 2. 1. Theoretical torque2. 2. Drive torque

h yd T =useful Thyd T0 DP 0.0016 = useful Thyd T0 PSI

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124 As with (1.2) above, from 100bar
(2) upwards and from 800
(3) As with (1.2) above, from 1450PSI
(2) upwards and from 11603PSI to 6000rpm, the drive torque of the pump should be increased by 15 to 30% compared with theoretical torque, thus
(3) to 6000rpm, the drive torque of the pump should be increased by 15 to 30% compared with theo- retical torque, thus

.

7--------------=useful TD

.

7--------------=useful T

2. 3. Quick calculation formula 2. 3. Quick calculation formula

= P 0.0023 = hyd HP DPSI 0.0189 P = Pressure in PSI N = rotation speed in rpm D = displacement in cu.in GPM = flow in GPMhyd HP and useful HP in HPhyd T and useful T in foot lbs GPM D 1231 P = Pressure in bar N = rotation speed in rpm D = displacement in mm
3 Q = flow in m
3 /shyd HP and useful HP in Whyd T and useful T in cm.NQD =

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N = 10
6– N
(1): Please consult our Technical Department.(2): for P (1): Please consult our Technical Department.(2): for P 1450PSI, please consult our Technical Department.(3): for N 100bar, please consult our Technical Department.(3): for N 800rpm, please consult our Technical Department. 800rpm, please consult our Technical Department.