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Q1. Name the three popular construction types of positive displacement pump?

Ans. The three popular construction type of a positive displacement pump are 1. Gear 2. Vane and 3. Piston.

Q2. how is the volumetric efficiency of a positive displacement pump determined?

Ans. Equation for calculating volumetric efficiency is given below

Volumetric efficiency = flow @ 10 psi/ flow at 0 psi.

Q3.  Name the important consideration when selecting a pump for a particular application?

Ans. A pump transfers fluid from one point to another point by converting the mechanical energy produced by the impeller into pressure energy.  As pressure is the key thing for any kind of pump so it is necessary for a user to consider the fluid property, they are going to transfer, environmental condition, operating speed, flow rate requirement and working period when it comes to select the pump for an application.

Q4. How is pressure developed in a hydraulic system?

Ans. We can develop pressure in a hydraulic system by altering the cross sectional area or we can also develop pressure by changing the distance between the motor and pump. As we all know that pressure is directly proportional to the force applied and inversely to the cross sectional area. So if we alter the cross sectional area we can alter the pressure.

Q5. Why should the suction head of a pump not exceed 5 psi?

Ans. Different pump design has different inlet pressure. This inlet pressure can be reduced by reducing the incoming water supply pressure (if necessary). Excessive inlet pressure can cause wear and tear of the inlet manifold seal. To prevent the flow thorough, the suction head pressure must be lesser than the backpressure by 5 psi unit. However the back pressure must not exceed the rate discharge pressure. 


Q6. What is the theoretical flow rate from a fixed displacement axial piston pump with a nine bore cylinder operating at 2000 rpm? Each bore has a 0.5- in diameter and the stoke is 0.75- in.



 Diameter (D) = 0.5 in

Stroke length (S) = 0.75- in

Speed (N) = 2000 rpm

Bore (Y) = 9.

We know that for a fixed displacement axial piston pump theoretical flow rate

Qth = A*D*N*Y*tan(o)/231

Qth = (.196)*(.5)*(2000)*(9)*(1.5)/231                                  { tan(o)= S/D => tan(o) = .75/.5}

Qth = 11.47 gpm.


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Q1. Name xxxxxxx three popular xxxxxxx types of xxxxxxx xxxxxxx pump?

Ans. xxxxxxx three popular xxxxxxx type of xxxxxxx positive xxxxxxx xxxxxxx are 1. xxxxxxx 2. Vane xxxxxxx 3. Piston.

Q2. xxxxxxx is the xxxxxxx efficiency of xxxxxxx positive displacement xxxxxxx xxxxxxx Equation xxxxxxx calculating volumetric xxxxxxx is given xxxxxxx efficiency xxxxxxx xxxxxxx @ 10 xxxxxxx flow at xxxxxxx psi.

Q3.  Name xxxxxxx important consideration xxxxxxx selecting a xxxxxxx for a xxxxxxx xxxxxxx A xxxxxxx transfers fluid xxxxxxx one point xxxxxxx another xxxxxxx xxxxxxx converting the xxxxxxx energy produced xxxxxxx the impeller xxxxxxx pressure energy.  xxxxxxx pressure is xxxxxxx key thing xxxxxxx xxxxxxx kind xxxxxxx pump so xxxxxxx is necessary xxxxxxx a xxxxxxx xxxxxxx consider the xxxxxxx property, they xxxxxxx going to xxxxxxx environmental condition, xxxxxxx speed, flow xxxxxxx requirement and xxxxxxx xxxxxxx when xxxxxxx comes to xxxxxxx the pump xxxxxxx an xxxxxxx xxxxxxx is pressure xxxxxxx in a xxxxxxx system?

Ans. We xxxxxxx develop pressure xxxxxxx a hydraulic xxxxxxx by altering xxxxxxx xxxxxxx sectional xxxxxxx or we xxxxxxx also develop xxxxxxx by xxxxxxx xxxxxxx distance between xxxxxxx motor and xxxxxxx As we xxxxxxx know that xxxxxxx is directly xxxxxxx to the xxxxxxx xxxxxxx and xxxxxxx to the xxxxxxx sectional area. xxxxxxx if xxxxxxx xxxxxxx the cross xxxxxxx area we xxxxxxx alter the xxxxxxx Why should xxxxxxx suction head xxxxxxx a pump xxxxxxx xxxxxxx 5 xxxxxxx Different pump xxxxxxx has different xxxxxxx pressure. xxxxxxx xxxxxxx pressure can xxxxxxx reduced by xxxxxxx the incoming xxxxxxx supply pressure xxxxxxx necessary). Excessive xxxxxxx pressure can xxxxxxx xxxxxxx and xxxxxxx of the xxxxxxx manifold seal. xxxxxxx prevent xxxxxxx xxxxxxx thorough, the xxxxxxx head pressure xxxxxxx be lesser xxxxxxx the backpressure xxxxxxx 5 psi xxxxxxx However the xxxxxxx xxxxxxx must xxxxxxx exceed the xxxxxxx discharge pressure. 


Q6. xxxxxxx is xxxxxxx xxxxxxx flow rate xxxxxxx a fixed xxxxxxx axial piston xxxxxxx with a xxxxxxx bore cylinder xxxxxxx at xxxxxxx xxxxxxx Each xxxxxxx has a xxxxxxx in diameter xxxxxxx the xxxxxxx xxxxxxx 0.75- in.



 Diameter xxxxxxx = 0.5 xxxxxxx length (S) xxxxxxx 0.75- in

Speed xxxxxxx = 2000 xxxxxxx (Y) = xxxxxxx xxxxxxx that xxxxxxx a fixed xxxxxxx axial piston xxxxxxx theoretical xxxxxxx xxxxxxx = A*D*N*Y*tan(o)/231

Qth xxxxxxx (.196)*(.5)*(2000)*(9)*(1.5)/231                                  { xxxxxxx S/D => xxxxxxx = .75/.5}

Qth xxxxxxx 11.47 gpm.


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