Recent questions tagged machinery

Description : What is something that is automated that shouldn't be? What is something that isn't that should be?

Last Answer : OMG…those DAMN automated answering devises that companies have. Push this…push that. Makes me boiling mad. Put a human being on the end of that phone!!! Make it that we can talk to a person & give people jobs.

Description : Explain Construction and working of Francis Turbine with neat sketch.

Last Answer : The main parts of the Francis turbine are: 1) Penstock: It is the large pipe which conveys water from the upstream of the reservoir to the turbine runner. 2) Spiral casing: It is a closed passage ... After doing the work the water is discharge to the trail race through the draft tubes.

Description : Derive equation for discharge through orifice meter with the help of neat sketch.

Last Answer : Orifice Meter or orifice Plate: It is a device used for measuring the rate of flow of a fluid through a pipe. It is Cheaper device as compared to venturimeter. It also works on the same ... a distance of about half the diameter of the orifice on the downstream side from the orifice plate. 

Description : Discuss the factors considered for selection of pump

Last Answer : 1) Pressure: Pump is ued to pressurize the fluid in system according to need of pressure we can select pump as below 2) Speed of pump: if the speed of pump is increased beyond its ... according to application we can choose it by economical aspect cost of pump & its spares should be less.

Description : State any four faults in centrifugal pump and their remedies

Last Answer : Sr.No Fault remedies 1 Pump fails to start pumping Reprime the pump , Clean the impeller Reduce suction lift , Increase the speed 2 Pump stops working ... Reduce the speed Correct the direction of rotation of impeller Reduce the discharge , Repair affected parts

Description : Draw and explain performance and operating characteristics curves of a Pelton turbine 

Last Answer : The followings are the important characteristic curves of a turbine : Main Characteristic Curves or Constant Head Curve. ... The speed of the turbine is varied by changing load on the turbine. For each value ... through the turbine as the load varies. Head may or may not kept constant.

Description : Explain the Need of draft tube in reaction turbine .state the types of draft tube used in it

Last Answer : Draft tube is a pipe of gradually increasing diameter which connects the exit of runner of turbine to tail race. In case of reaction turbine , one part of available head is converted into K.E before ... . iv. Elbow draft tube with circular cross section at inlet and rectangular at outlet.

Description : Draw the layout of hydroelectric power plant and classify the turbines used in it.

Last Answer : Layout of hydroelectric power plant: Classification of the hydraulic turbines: According to the type of energy available at inlet to the turbine 1)impulse turbine and 2) Reaction turbine ... speed of the turbine 1)low specific speed 2)medium specific speed 3)High specific speed

Description : List various minor losses in fluid flow. Explain any one type with sketch and formula.

Last Answer : List various minor losses a) Sudden expansion of pipe b) Sudden contraction of pipe c) Pipe fittings d) Bend in pipe e) Loss of head at Entry. f) Loss of ... The head loss resulting from pipe expansion may be greatly reduced by introducing gradual pipe transition known as diffuser. 

Description : Explain water hammer phenomenon and state the remedies measures to avoid it.

Last Answer : Water hammer phenomenon: commonly occurs when a valve closes suddenly at an end of a pipeline system, and a pressure wave propagates in the pipe. Water hammer (or hydraulic shock) is the momentary increase in ... . caused by the moving water. 7) Use high strength pipes. 8) Close the valve slowly.

Description : Compare i) Steady and uniform flow ii) Laminar and turbulent flow

Last Answer : Steady flow:- The flow is said to be steady when the flow characteristics, such as velocity, pressure, density and temperature do not change with time. Water flowing through a tap at a constant rate is an ... called as turbulent flow. e.g. The flow of river at the time of flood is turbulent flow.

Description : Explain Bernoulli’s theorem with neat sketch. State its two important assumptions.

Last Answer : This theorem states that whenever there is continuous flow of liquid the total energy at every section remains same provided that there is no any addition or loss of energy.  Let us consider ... incompressible. 4. Velocity is uniform over the cross section. 5. The flow is irrotational.

Description : Draw sketch of Bourdon tube pressure gauge and state its advantages.

Last Answer : Advantages:  • These give more accurate results. • Bourdon tube cost low. • Bourdon tube are simple in construction. • They can be modified to give electrical outputs. • They are safe even for high pressure measurement. • Accuracy is high especially at high pressures.

Description : Draw indicator diagram for reciprocating pump showing the effect of accelerating head and frictional head.

Last Answer : Draw indicator diagram for reciprocating pump showing the effect of accelerating head and frictional head.

Description : State the difference between Static head & Manometric head in centrifugal pump.

Last Answer : Static head: The sum of suction head & delivery head is known as static head.  Manometric head: It is the total head that pump is required to develop. This include all losses. This is equal to difference between pressure head at inlet & outlet of pump.

Description : State the need of surge tank in hydroelectric power plant.

Last Answer : It is the tank provided in the path of penstock to avoid pulsating discharge at inlet of turbines. To reduce effect of water hammer surge tanks are provided. During flow of ... reservoir to turbine through penstock pressure surges are created to compensate these surges surge tank is provided.

Description : Write Chezy’s equation for frictional losses and list all the terms involved in it.

Last Answer : Where; V = velocity of water in pipe,  m = hydraulic mean depth =A/P = d/4  I = loss of head per unit length,  C = Chezy’s constant

Description : Show the difference between hydraulic gradient line & total energy line with the help of suitable diagram.

Last Answer : Show the difference between hydraulic gradient line & total energy line with the help of suitable diagram.

Description : The pressure in the tyres of the four wheeler was measured as 33. State the unit of pressure in this case. Name the device use to measure this pressure.

Last Answer : The unit of pressure 33 in this case is PSI (Pound per square Inch).  The name of device used to measure is Bourdon Tube Pressure Gauge

Description : Compare water and oil of specific gravity 0.8 on the basis of density & viscosity.

Last Answer : Here it is not possible to find out viscosity

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