 Hello students, myself Siddhaswara B. Tulsapure, associate professor, Department of Mechanical Engineering, Walshan Institute of Technology, Solopur. So in this session, we are going to deal with the circuits using intensifiers and accumulators. So the learning outcome. So at the end of this session, students will be able to draw hydraulic circuits having the intensifiers and accumulators and explain their working, the contents are. So firstly we will have introduction to intensifiers, then we will go for circuits using intensifiers, then introduction to accumulators, circuits using accumulators, and lastly the references. Let us have first introduction to the intensifiers or another name to that one it is pressure boosters. So we are knowing that say the clamping operation and say other similar operations, we are in need of very high pressures. So those pressures can be obtained say through the devices which are intensifiers. Say in case of the intensifiers, we are having the somewhat the types as these. So the construction and working you can observe here. So the difference in the areas it is made to get the difference in the pressure. The principle on which it works is P1A1 is equal to P2A2. Say P1 it is lower pressure, A1 it is larger area of the piston on the left hand side and P2 it is the larger pressure and A2 it is the smaller area, it is on the right hand side. So in every case. So now in case of these, we are having this principle which we are going to use and this pressure which is developed that is P2, we are again if needed we are converting it into the say force by supplying this pressurized oil to the say cylinder etcetera. So in some cases you can go make use of the directly that pressure that is in case of the pressure busting machines etcetera where testing it is done. So this is the pressure testing with reference to the busting operation and now we are going to come across the use of the say these intensifiers or pressure boosters in the circuit. See now the clamping or say riveting operation etcetera where that tail of the rivet it is to be again converted into the head like structure and the plates these are to be say joined with the help of the rivet. So there or you can think of the operations like clamping etcetera where where you have forces these are needed say if the multi-point cutting tool is there like milling etcetera or number of surfaces these are being machined at a time. So like this number of cases are there where high pressure or high force it is the requirement at that time we are going for the use of intensifiers. Now see the circuit diagram we are having this one as say 4 by 2 direction control wall solenoid operated and spring retentatives and P is presently connected to A P port connected to A. So it is going to the left hand side of this intensifier. So area here it is larger so we are supplying the low pressure fluid. So this fluid may be even gas or air etcetera. So you can make use of the liquid or you can make use of the gaseous fluid. So now the pressure of that one it is lesser. So here you can observe the piston cross section area or piston area it is lesser. So because of that one it is going to deliver the high pressure oil it is. So here the liquid it is going to be there. So here no gas will or air it is going to be there. So here the liquid phase of that fluid it is needed. So liquid that is oil generally so it is coming outside. So high pressure oil it is coming outside. So it goes to this one say it is check wall say ball like structure it is coming first say no further flow. So it goes to the say cylinder say it is single acting cylinder say it is spring return. So high pressure oil it is going inside the cylinder. So it is exerting high pressure on the piston. So piston is say applying larger force for the clamping or the riveting operation. So this is one of the applications of the say pressure booster or intensifier in the hydraulic circuit. Now one more thing on the top hand top side you can observe it is make up tank we are saying. So as we are having the very high pressures obtained with the help of the intensifiers and these are needed for those particular operations. So what happens is we might have some leakages even though we are having the seals corresponding to those pressures that is high pressure seals these are used still there are chances of having the leakages. So in case of those so the oil quantity it may get reduced. So we are having the make up tank. So from where the oil it is going to come through the check wall and it will be say supplied to the cylinder. So now you can have the reverse stroke of this one that is the backward stroke. So when the spool it is shifted P gets connected to B the supply to this port will be there. So piston it is going to come backwards and at that time so we are having again when no supply is there the spring return of this piston it is going to take place. The oil which is there in the cylinder it is going to come back to this particular zone and it is going to remain here and in the next cycle it is going to come outside and again it is going to enter the clamping cylinder. So like that the operation will be there. So this is one that is the circuit with the intensifier. Next to that one we will have the accumulators. These are the devices which are used to store the oil under pressure and supply whenever there is need. So different types of the accumulators you are knowing it is weight loaded accumulators, spring loaded accumulator or air or gas type of the accumulator where separator and non separator type also these are coming. Now the different functions of the accumulators we are having the one which is appearing in the red color so this one we are going to observe it is say shock absorber it is going to act as then the other things are there so those we are not going to have here. So it is the fifth one you can have so it is to maintain steady pressure over a period of time without keeping the pump operating continuously that is what the second circuit we are going to observe. So let us go for the circuits using these accumulators. See the first circuit first we said so it is to absorb the shocks. So when we are saying to absorb the shocks when the shocks are generated say in case of this one you can think of the circuit and when the shocks are generated so that you can think of see the accumulator it is used to absorb the shocks but the shocks are there going to be before that one. See now here what is happening is spool it is having three different positions in case of the direction control valve when the shifting of the spool it is going to occur. See what happens is pump supply it is P port it is getting suddenly closed now presently we are having this one as closed and then it goes to the left side or right side then P gets connected to A or P gets connected to B etc but from this left side when we are obtaining this condition sudden closure of that pressure port will be there. So here also so when it is being shifted to the last position then also the sudden closure and then having the connection of P to the B. So like that what we are having is the supply from the pump it is continuous but in case of this one we are having the sudden closure of this pressure port during the shifting of the spool and at that time the shock waves these are generated and say in case of these the shocks if these are not absorbed the fittings etc these are going to loosen and we are going to have the leakages to avoid that one what we should have is we should have the absorption of those shocks. Now see where we have mounted this accumulator and the connection you can observe. So on the top side we are shown the wall so it is meant for the inserting the say gas or air so you can observe the say one type of the accumulator I have shown here so it is gas chamber so you can introduce that gas from the top side and we are having the say the oil from the reservoir it is coming through the strainer through the pump through this check wall it is going so on the left hand side we are having pressure relief wall it goes to the accumulator and it also goes to the direction control wall. So storage of that oil will be there under this gas pressure so when sudden closure of that port P of the direction control wall will be there so at that time the oil it is going to enter the accumulator and gas it is getting compressed because of which we are having the absorption of the shocks here so thus the accumulator it is used for to absorb the shocks due to the sudden closure of the ports etc. So see the connection so it is taken from here to the accumulator inlet next one more say circuit we will have so in case of the few operations like say curing of the say rubber is there so rubber curing process presses you can consider and then next to that one you can consider the sluice gates where the gate is positioned for a longer period of time it is so at one place so in case of this say what that accumulator is going to do is it is going to reduce the power requirements so then heating of the oil and also wear of parts so these things these are going to occur that is say heating of the oil and say the wear of the parts etc and also the power requirement higher so when the oil it is passing continuously through the say pressure relief wall so in case of this we are going to come across the release of the pressurized oil at lower pressures through the unloading wall you can observe the unloading wall here so now see how this is say with the help of the this say accumulator we are having the pressure it is maintained on the that particular say workpiece or whatever that object is there and in case when the say pressure it is going to become more so this unloading wall it is going to open so unloading wall it is also normally closed wall unloading wall it is going to open this inlet will get connected to outlet and outlet of the say unloading wall it is going to the reservoir again see in this case we are able to maintain the pressure or the force on that object so even though the pump it is say now it is stopped so what we are having is we are having the reduced power requirements heating of the oil it is reduced and wear of the parts it is reduced because the oil is being passed through the unloading wall at lower pressures that is what is happening so you can have the pump running still it is the oil is going to pass at lower pressures through the unloading wall and if possible you can even say stop the pump that is also possible so these are the references