PURCHASING METHOD OF PUMP TECHNICAL

1 . Tota| Head (m)

Total head is determined by the vertical distance from the suction water level to the discharge
water level and friction loss according to the pipe length and other losses.
If the friction loss of head is not availab|e, following things shall be specified.

① The length of suction pipe and the kind/number of pipe joints

② The length of discharge pipe and the kind/number of pipe joints

2. Flow Rate (㎥/sec, ㎥/min, ㎥/hr, ㎥/day)

The required flow rate is indicated by second minute and hour.

3. Quality of Fluid

Followings are recommended to specify, because the properties of fluid exercise infhence on the
performance of power and pump, material of the pump, and shaft seal equipment etc.

① The kind of fluid (c|ear water, sea water, acid, a|kali and so on)

② Specific weight(kg/m3)

③ Temperature (℃, ℉)

④ Viscosity (Poise, Centi-Poise)

4. Prime Mover

① Kind and type of prime mover

② In case of the motor, voltage, pole and frequency(Hz)

③ Kind of shaft coupling (direct coupling, belt)

5. Pump

① The type of pump (example:sing|e suction volute pump, turbine pump etc.)

② Direction of suction inlet/discharge outlet (example:horizontal suction, vertical delivery etc.)

③ Diameter of SUCtion in|et and discharge out|et (example: 50 × 40 it is indicated at
the format for suction inlet and at the latter for discharge outlet)

④ Rotational direction of pump (counterclockwise, Clockwise)

⑤ ln case of vertical pump, the |ength of pump (example : 1 M)

6. Calculation Method of Pump Power

① Theoretical Power

WHP = 0.163 γQH(kW) = 0.163 γQH(kW)
Q = Flow rate(㎥/min)
H = Head(m) Head
    = 0.222 γQH(HP)
γ = Specific Weight

② Braking Power

BHP = WHP/ηp
(The scale effect of pump is variable to the flow rate and dis-relative rotational velocity)

③ (Motor Power)

MHP = BHP(1+α)
(α is the allowance rate of motor, which is variable to the power)