Formulae –

1. Total Head (H)= 10 × (Suction Pressure + Delivery Pressure) in m
   

2. Q= (A×h)/t
   Q= Actual discharge
   A = Cross-sectional area of the discharge/collection tank
   h = Height of tank to be filled (0.1 m or 10 cm)
   t = Time to fill 10 cm of tank
   

3. Power input for single acting reciprocating pump
   P_Input=(3.6×10×n ×1.36)/(K ×t_rev )
   n= Number of meter revolutions (10 in this case)
   t_rev= Time taken for 10-meter revolutions
   K= Meter constant (15.018)
   

4. The power output by Pump is given by
   P_Output=(W×Q×H)/75
   W = Specific weight of water (1000 Kg/m³)
   Q = Actual discharge
   H = Total head
   

5. η=P_Output/P_Input ×100
   

Procedure –

1. Start the motor and open the delivery valve fully
   
2. Set the Suction pressure to 0 Kg/cm²,
   
3. Note down the delivery pressure
   
4. Close the gate valve at the outlet of the discharge tank and note down the t in seconds to fill the tank upto a height of 10 cm and open the gate valve again
   
5. Note down the time t_rev in seconds for 10 revolutions of meter
   
6. Repeat steps 3 to 6 for suction pressure of 1,2,3 and 3.5 Kg/cm²
   

Observations -

Cross-sectional area of the discharge/collection tank, A = 0.25 m²
Height of tank to be filled, h = 0.1 m or 10 cm
Meter constant, K= 15.018
Specific weight of water, W= 1000 Kg/m³

Calculations –

Perform the following calculations for each opening of the delivery valve:

1. Total Head (H)= 10 × (Suction Pressure + Delivery Pressure) in m
   

2. Q= (A×h)/t
   

3. P_Input=(3.6×10×n ×1.36)/(K ×t_rev )
   

4. P_Output=(W×Q×H)/75
   

5. η=P_Output/P_Input ×100
   

6. Plot the following curves
   i) H_m vs Q
   ii) H_m vs P_output
   iii) H_m vs η