DESC:FIELD The present disclosure relates to the field of arrangements for removing condensate from a heat exchanger. BACKGROUND Steam is one of the most widely used working fluid in the process industries such as textile, pharmaceutical, oil & gas, power generation and the like. Steam is also used as a heat transfer fluid in process industries. A steam trap is used to discharge condensate. A conventional steam trap is connected to a heat exchanger via a first condensate header. The steam trap is configured to separate steam vapours from the condensate, and to supply the condensate to a feed water tank via a second condensate header. Under normal operating conditions, the pressure in the first condensate header is more than the pressure in the second condensate header. This facilitates flow of the condensate from the heat exchanger to the steam trap and from the steam trap to the feed water tank. However, in some operating conditions, the pressure in the first condensate header may reduce, and can become lower than the pressure in the second condensate header. Due to this, the removal of the condensate from the heat exchanger is interrupted, thereby causing accumulation of the condensate inside the heat exchanger which adversely affects the heat transfer in the heat exchanger. Hence, in order to overcome the aforementioned drawbacks, there is need of an arrangement that facilitates removal of a condensate from a heat exchanger even when the pressure inside the heat exchanger drops below or becomes equal to pressure in a condensate discharge pipe. OBJECTS Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows: It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative. An object of the present disclosure is to provide an arrangement that efficiently removes condensate from a heat exchanger. Another object of the present disclosure is to provide an arrangement that facilitates the removal of the condensate from a heat exchanger even when the pressure inside the heat exchanger drops below that of the downstream pressure. Yet another object of the present disclosure is to provide an arrangement for removing condensate from a heat exchanger that is compact. Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure. SUMMARY The present envisages an arrangement for removing condensate from a heat exchanger. The arrangement includes a vessel, a buoyant body disposed in the vessel, a four bar linkage, and an actuator link. The vessel has a condensate inlet port in fluid communication with an outlet of the heat exchanger to receive condensate, a condensate outlet port in fluid communication with the condensate discharge pipe, a steam inlet port in fluid communication with a steam source, and a steam outlet port. The four bar linkage has a fixed link, a crank connected to the fixed link and the buoyant body, a driven link connected to the fixed link, and a coupler link connected to the crank and the driven link. The actuator link is pivotally connected to a pivot and connected to a junction of the driven link and the coupler link via a biasing member. The actuator link is configured to be displaced between a first stopper and a second stopper under influence of the biasing member. The arrangement further includes a first slider link and a condensate outlet valve. The condensate outlet port is connected to the first slider link. The first slider link is coupled to the crank and is linearly displaced under the influence of the crank. Further, the condensate outlet valve is configured to open or close the condensate outlet port. In an embodiment, ratio of angular displacement of the crank to the angular displacement of the driven link is more than 1. The aspect ratio of the buoyant body is less than 2. The arrangement comprises a steam inlet valve and a steam exhaust valve. The steam inlet valve is configured to be linearly displaced under influence of the actuator link. The steam inlet valve is configured to open or close the steam inlet port. The steam inlet valve rests against an operative outer surface of the steam inlet port. The steam exhaust valve is connected to the actuator link in a plane parallel to the steam inlet valve, and is configured to be linearly displaced under influence of the actuator link. The steam exhaust valve is configured to open or close the steam outlet port. The steam exhaust valve rests against an operative inner surface of the steam outlet port. In an embodiment, ratio of angular displacement of the crank to the angular displacement of the driven link is more than 1. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING An arrangement for removing condensate from a heat exchanger, of the present disclosure, will now be described with the help of the accompanying drawing, in which: Figure 1 illustrates a schematic view of a system in the process industry with a conventional steam trap; Figure 2 illustrates a schematic view of a system in the process industry with an arrangement of the present disclosure; Figure 3A illustrates a schematic view of a four bar linkage of the arrangement, in accordance with an embodiment of the present disclosure; Figure 3B illustrates a schematic view of the arrangement including a snap over center and trapping mechanism (lower level position) with a motive steam inlet port closed, in accordance with an embodiment of the present disclosure; Figure 3C illustrates a schematic view of a snap over center mechanism showing steam exhaust valve and seat (lower level position) with a steam outlet port open, in accordance with an embodiment of the present disclosure; Figure 4A illustrates another schematic view of the four bar linkage of the arrangement of the present disclosure; Figure 4B illustrates a schematic view of the four bar linkage with the snap over center and trapping mechanism (upper level position) at upper snap point with motive steam inlet port closed, in accordance with an embodiment of the present disclosure; Figure 4C illustrates a schematic view of the snap over center mechanism showing steam exhaust valve and seat (upper level position) with steam outlet port open, in accordance with an embodiment of the present disclosure; Figure 5A illustrates a schematic view of the four bar mechanism including the snap over center and trapping mechanism (upper level position) with motive steam inlet port open, in accordance with an embodiment of the present disclosure; Figure 5B illustrates a schematic view of the snap over center mechanism showing the steam exhaust valve and seat (upper level position) with steam outlet port closed, in accordance with an embodiment of the present disclosure; Figure 6A illustrates a schematic view of the four bar mechanism including snap over center and trapping mechanism (lower level position) with motive steam inlet port open, in accordance with an embodiment of the present disclosure; Figure 6B illustrates a schematic view of the snap over center mechanism showing steam exhaust valve and seat (lower level position) with steam outlet port closed, in accordance with an embodiment of the present disclosure; Figure 7A and Figure 7B illustrate isometric views of the arrangement, in accordance with an embodiment of the present disclosure; Figure 8A, Figure 8B, and Figure 8C illustrate side views of a first cam and follower mechanism used in the arrangement of the present disclosure; Figure 9A illustrates a side view of a buoyant body and the four bar mechanism used in the arrangement of the present disclosure; Figure 9B and Figure 9C illustrate side views of the buoyant body and the four bar mechanism, in accordance with another embodiment, used in the arrangement of the present disclosure; and Figure 10A and Figure 10B illustrate side views of the buoyant body and the four bar mechanism, in accordance with yet another embodiment, used in the arrangement of the present disclosure. LIST OF REFERENCE NUMERALS 1, 1a – Crank 2, 2a – Coupler link 3, 3a – Driven link 4 – Fixed link 5, 5a – Actuator link 6 – Biasing member 7, 7a – Steam inlet valve 8, 10, 18 – Seat 9 – Steam exhaust valve 11, 11a – First slider link 12, 12a – Condensate outlet valve 100 – Conventional system 102 – First steam header 104 – Control valve 106 – Second steam header 108, 208 – Heat exchanger 110 – First process fluid header 112 – Second process fluid header 114 – First condensate header 116 – Conventional steam trap 118 – Condensate return header 120 – Second condensate header 122 – Check valve 124 – Bypass valve 200 – System 202 – First steam header 204 – Control valve 206 – Second steam header 210 – First process fluid header 211 – First condensate header 212 – Condensate inlet check valve 213 – Steam inlet header 216 – Steam outlet pipe 218 – Feed water tank 220 – Condensate discharge pipe 222 – Condensate outlet check valve 400 – Arrangement of the present disclosure 402 – Vessel 404 – Condensate inlet port 406 – Buoyant body 408 – Mounting bracket 410 – Mounting base 412 – Condensate outlet port 414 – Steam inlet port 416 – Steam outlet port DETAILED DESCRIPTION Figure 1 illustrates a schematic view of a system 100 used in the process industries, such as textile, pharmaceutical, oil & gas, and the like, with a conventional steam trap 116. The system 100 comprises a first steam header 102 that allows a passage of steam therethrough. The first steam header 102 terminates into a control valve 104 that regulates the supply of steam into a second steam header 106 that is connected to the control valve 104. The second steam header 106 is in fluid communication with a heat exchanger 108 and supplies the steam into the heat exchanger 108. A first process fluid header 110 supplies the process fluid (the fluid that needs to be heated) into the heat exchanger 108, wherein thermal communication between the steam and the process fluid takes place, thereby heating the process fluid and condensing the steam. The temperature of the process fluid inside the first process fluid header 110 is Tf1. The heated process fluid, at an increased temperature of Tf2, is evacuated from the heat exchanger via a second process fluid header 112 which carries the process fluid. The condensate is evacuated from the heat exchanger 108 via a first condensate header 114. The first condensate header 114 is in fluid communication with a steam trap 116, which is configured to separate the steam vapours from the condensate and supply the condensate into a condensate return header 118 that is usually connected to the feed water tank via a second condensate header 120 that is in fluid communication with the steam trap 116 and the condensate return header 118. A check valve 122 is mounted on the second condensate header 120 to regulate the supply of the condensate into the condensate return header 118. P1 is the pressure of the steam in the first steam header 102, P2 is the pressure of the steam in the second header 106, and P3 is the pressure of the condensate in the second condensate header 120. The pressure of the condensate in the first condensate header 114 is roughly equal to P2 as there is very little pressure drop in the heat exchanger 108 during operation. The pressure P3 in the steam trap acts as a back pressure against the pressure P2 inside the steam trap 116. The outlet of the steam trap 116 is connected to the second condensate header 120 through the check valve 122 maintained at a pressure usually above gauge pressure and at an elevation H such that the effective pressure acting at the outlet of the steam trap 116, which is referred to as the back pressure, is P3. Typically, the state of the steam entering the heat exchanger 108 is dry saturated corresponding to the steam pressure P2 so that any heat transfer taking place from the steam to the process fluid is the latent heat of condensation of the steam at the pressure P2. The temperature of the steam, TS is a function of the steam pressure in the saturated region and once the pressure is kept constant, the temperature also remains constant. Hence, by controlling the pressure P2, the temperature of the steam TS is controlled. The control valve 104 controls the pressure P2 in accordance with the feedback from a temperature sensor TT mounted on the second process fluid header 112. It thereby controls the steam temperature TS, and hence, the heat transfer rate from the steam to the process fluid. The steam trap only allows condensate (steam that has condensed after transferring its latent heat of condensation) to flow out thereby ensuring that the entire latent heat of condensation has been transferred from the steam to the process fluid. Flow rate of condensate out of the steam trap 116 is a function of the differential pressure which is the difference between the pressure P2 and the back pressure P3. The flow rate of condensate out of the steam trap 116 increases with the increase in differential pressure and reduces to zero when the differential pressure is zero. This is due to the fact that when the pressure P2 is greater than the back pressure P3, the steam pressure itself pushes the condensate out of the steam trap 116. This condensate is usually recovered through the second condensate header 120 which is connected to a condensate recovery system that returns the condensate back to the feed water tank of the boiler. Assuming steady state conditions, the heat transfer rate required from the steam to the process fluid flowing, steadily at a mass flow rate (mp) is, Q = mp * C * (Tf2-Tf1) Where, C = avg. specific heat of the process fluid between Tf2 and Tf1 (KJ/kg-K) mp = mass flow rate of the process fluid (kg/s) Q = heat transfer rate required (KJ/s or KW) For a heat exchanger of known heat transfer coefficient U (W/m2-K) A = Q / (U*LMTD) Where, A = required area of heat transfer of the heat exchanger (m2) LMTD = Logarithmic mean temperature difference in the heat exchanger LMTD = (Tf2-Tf1)/ [ln {(Ts-Tf1)/ (Ts-Tf2)}] Having found out the steam temperature (TS), the corresponding saturation pressure P2 can be determined, and the mass flow rate of steam required can be calculated as, ms = Q/hfg at P2 Where, hfg at P2 = latent heat of condensation of steam at process pressure P2 (KJ/kg) ms = mass flow rate of steam required (Kg/s) Using the above relations, the required steam temperature TS can be evaluated, and correspondingly the required pressure P2 and the steam flow rate can be determined. Thus, for a steady state condition, the heat exchanger is selected on the basis of the following two primary requirements: • the maximum heat transfer rate Q; and • the steam temperature TS and the corresponding pressure P2 such that P2>P3, thereby ensuring that the differential pressure across the steam trap 116 is positive. Hence, by appropriately sizing the steam trap 116 for the lowest possible differential pressure, the condensate can be effectively removed from the heat exchanger 108. In many process applications, the mass flow rate of the process fluid (mp) may not be steady but varies with time even though the process fluid outlet temperature Tf2 may be required to be kept constant or alternatively for a constant mass flow rate of the process fluid, the required process fluid outlet temperature Tf2 may vary with time. There are instances where both the mass flow rate of the process fluid as well as the temperature Tf2 may vary with time. However, in both cases, the heat exchanger will still have to be designed for the maximum heat transfer rate Q. As the required heat transfer rate reduces for a given heat exchanger and back pressure P3, the required steam temperature TS reduces as per the function obtained as follows: Q = U * A * LMTD mp * C * (Tf2-Tf1) = [U * A * (Tf2-Tf1)] / [ln {(TS-Tf1)/ (TS-Tf2)}] ln {(TS-Tf1)/ (TS-Tf2)} = (U * A )/ (mp * C ) {(TS-Tf1)/ (TS-Tf2)} = e^ [(U * A)/ (mp * C)] TS = {Tf1 – Tf2* e^ [(U * A)/ (mp * C)]} / {1 - e^ [(U * A)/ (mp * C)]} Where, e is the exponential function. From the above relation, in the first case, when Tf2 has to be maintained constant and mp is a variable and reduces, the corresponding pressure P2 also reduces. In the second case when mp is constant and Tf2 reduces, the required pressure P2 again reduces. In other words, as the required heat transfer rate reduces the required steam temperature TS, and correspondingly the pressure P2 also is also reduced. Thus, the system 100 is under normal operation when the heat exchanger 108 operates at heat transfer rates close to the heat exchanger maximum design conditions, the steam temperature TS is the highest and the corresponding pressure P2 is also the highest, thereby giving the maximum differential pressure (DP) across the steam trap 116. Such a condition will hereby be termed as pure steam trapping, and for an appropriately sized steam trap 116, the condensate flow rate out of the steam trap 116 will be maximum. The pressure P2, in this case, will be adequate to push the condensate out of the steam trap 116 against the back pressure P3 at a rate greater than the rate of condensation of steam in the heat exchanger 108. When the required heat transfer rate reduces, i.e., when required Tf2 is reduced, the corresponding pressure P2 will reduce and at a certain required heat transfer rate, the pressure P2 will be just enough to push the condensate out of the steam trap 116 against the back pressure P3 at a rate equal to the rate of condensation of steam in the heat exchanger 108. Any further reduction in the required heat transfer rate will cause the process pressure P2 to drop, and the rate of condensate removal will become less than the rate of condensation within the heat exchanger 108. This will lead to the backing up of condensate in the heat exchanger 108. This condition is the beginning of a stall which will be referred to as stalling, where the required differential pressure across the steam trap 116 becomes marginally greater than the actual differential pressure. In the case, where the required heat transfer rate reduces to the point that the differential pressure across the steam trap 116 becomes equal to or less than zero, there will be no condensate removal from the steam trap 116 and such a condition will hereby be termed as pure stalling. From the beginning of stalling to pure stalling, the condensate that backs up into the heat exchanger 108 reduces the effective area of heat transfer, thereby leading to a drop in the process fluid outlet temperature Tf2. In order to avoid this situation, the condensate is drained via a bypass valve 124 into an open drain as shown in Figure 1. This leads to a loss of condensate which has to be made up as fresh make up water in the feed water tank, and also increases the fuel consumption due to the additional sensible heat that needs to be transferred to the makeup water in the boiler. The condensate, in the pure trapping condition, would have been returned at the steam temperature TS or the maximum temperature of operation of the condensate recovery system which is typically around 90 ºC (provided pressure powered pumps are used). The fresh make up water also needs to be treated which adds to the cost. For certain conditions, the required heat transfer rate will reduce to such an extent that the pressure P2 may fall below atmospheric pressure. Draining condensate into an open drain will only be due to the head of condensate above the bypass valve. Also, due to the lower process pressure than atmospheric pressure, there are chances of air ingress into the heat exchanger through the bypass valve which may lead to corrosion of the heat exchanger and the condensate recovery pipe line over a period of time. In order to overcome the aforementioned drawbacks, the present disclosure envisages an arrangement for removing condensate from a heat exchanger (hereinafter also referred to as arrangement) to be used in the process industries. The arrangement, of the present disclosure, facilitates the removal of the condensate from the heat exchanger even when the pressure inside the heat exchanger falls below that of the downstream pressure. The arrangement, of the present disclosure, is now described with reference to figure 2 through figure 10B. Figure 2 illustrates a schematic view of a system 200 in the process industry with an arrangement 400, of the present disclosure. The system 200 comprises a first steam header 202 that allows the passage of steam therethrough. The pressure of the steam inside the first steam header 202 is P1. The first steam header 202 terminates into a control valve 204. A second steam header 206 facilitates the fluid communication between the control valve 204 and a heat exchanger 208. More specifically, the control valve 204 regulates the supply of the steam from the first steam header 202 into the heat exchanger 208 via the second steam header 206. The steam entering the heat exchanger 208 is a pressure P2 and temperature TS. The system 200 further comprises a first process fluid header 210 that allows the passage of the process fluid into the heat exchanger 208. The temperature of the process fluid entering the heat exchanger 208 is Tf1. After the process fluid enters the heat exchanger 208, thermal communication between the process fluid and the steam causes an increase in the temperature of the process fluid to Tf2 and also causes the steam to condense. The condensate is removed from the heat exchanger 208 via a first condensate header 211. The first condensate header 211 supplies the condensate to the arrangement 400, of the present disclosure, via an inlet check valve 212. The system 200 further includes a steam inlet header 213 that facilitates the fluid communication between the first steam header 202 and the arrangement 400. The arrangement 400 is also in fluid communication with the first condensate header 211 via a steam outlet pipe 216. The condensate collected in the arrangement 400 is supplied to a feed water tank 218 via a condensate discharge pipe 220. The pressure of the condensate inside the condensate discharge pipe 220 is P3. An outlet check valve 222 regulates the flow of the condensate from the arrangement 400 into the feed water tank 218. The arrangement 400 operates in two operative configurations, i.e., a first configuration and a second configuration. The arrangement 400 operates in the first configuration when pressure P2 in the heat exchanger is greater than the pressure P3 in the condensate discharge pipe 220. The arrangement 400 operates in the second configuration when the pressure P2 in the heat exchanger is lower than or equal to the pressure P3 in the condensate discharge pipe 220. The arrangement 400 includes a vessel 402, a buoyant body 406, a four bar linkage, and an actuator link 5. A condensate inlet port 404, a condensate outlet port 412, a motive steam inlet port 414, and a steam outlet port 416 are configured on the vessel 402. The condensate inlet port 404 is in fluid communication with the steam/condensate outlet of the heat exchanger 208 to receive condensate. More specifically, the steam/condensate outlet of the heat exchanger 208 is connected to the inlet check valve 212 at a height Hf (also known as the filling head, wherein Hf is the distance between the bottom of the heat exchanger 208 and the upper level L2) whose outlet is connected to the condensate inlet port 404. The inlet check valve 212 allows flow of condensate only in one direction, i.e. towards the condensate inlet port 404 of the vessel 402. The condensate outlet port 412 is in fluid communication with the condensate discharge pipe 220 via the outlet check valve 222. The condensate discharge pipe 220 is further connected to the feed water tank usually maintained at a pressure above atmospheric pressure. The condensate inlet port 404 and the condensate outlet port 412 are configured to facilitate inflow and outflow of the condensate respectively. The effective back pressure P3 is the sum of this pressure head and the feed water tank 218 / condensate header pressure. The motive steam inlet port 414 of the vessel 402 is in fluid communication with a steam source via the first steam header 202 that is maintained at pressure P1. The steam outlet port 416 of the vessel 402 is in fluid communication with the heat exchanger 208. In an embodiment, the steam outlet port 416 is connected back to the first condensate header 211. In another embodiment, the steam source is a boiler. The construction of the arrangement 400 is now described with reference to Figure 3A through Figure 10B. Referring to Figure 3A, the buoyant body 406 is disposed within the vessel 402. The buoyant body 406 is floatable on the condensate. The four bar linkage (as shown in figure 3A) is disposed in the vessel 402. Each link of the four bar linkage mechanism is numbered from 1 to 4 and pin jointed as shown. The four bar linkage includes a crank 1, a coupler 2, a driven link 3, and a fixed link. The crank 1 is hingeably connected to the buoyant body 406 and the fixed link 4. The coupler link 2 is connected between the crank 1 and the driven link 3. The link 4 is the fixed link. The driven link 3 is connected to the fixed link 4 and the coupler link 2. The pin joint between the crank 1 and the fixed link 4 is A. Similarly, the pin joint between the coupler link 2 and the crank 1 is B. The pin joint between the coupler link 2 and the driven link 3 is joint C. The joint D is the pin joint between the driven link 3 and the fixed link 4. The joints A and D are fixed because of the fixed link 4. The crank 1 rotates about the fixed joint A because of the buoyant force that acts on the buoyant body 406 when the condensate starts filling inside the vessel 402. The two positions of the buoyant body 406 and the four bar linkage are shown in Figure 4. The second position of all the links are indicated as dotted lines and subscripts for the linkages and joints are 1’, 2’, 3 and B’, C’ respectively. The fixed link 4 and the joints A, D remain in the same position. The lower position of the four bar linkage mechanism corresponds to a lower level L1 of the condensate within the vessel 402, and the upper position corresponds to an upper level L2 of the condensate within the vessel 402. The four bar linkage mechanism is sized in such a manner that the angular displacement represented by angle ?1 which is swept by the crank 1 as it moves from the lower position to the upper position is amplified by a factor greater than 1 into the angular displacement of the driven link 3 represented by the angle ?2 swept by the driven link 3. In other words, (Angle ?2 / Angle ?1) > 1 More specifically, ratio of angular displacement of the crank 1 to the angular displacement of the driven link 2 is more than 1. In an embodiment, the ratio of angular displacement of the crank 1 to the angular displacement of the driven link 2 is more than 1.5. The amplification of the angular displacement of the crank 1 makes it possible to reduce the volume swept by the buoyant body 406 for a defined angle ?2. This, in turn, reduces the size of the arrangement 400 for a given capacity, thereby making the arrangement 400 compact. The arrangement 400 further comprises a first slider link 11, and a condensate outlet valve 12. The first slider link is coupled to the crank 1. The condensate outlet valve 12 is connected to the first slider link 11 which is configured to operate the condensate outlet port 412. The first slider link 11 is configured to be linearly displaced under the influence of the crank 1. More specifically, the first slider link 11 is constrained to move linearly by the sliding joint I. The condensate outlet valve 12 is configured to restrict the condensate outflow through the condensate outlet port 412 when the condensate level falls below the lower level L1 within the vessel 402. The condensate outlet valve 12 rests against a trap seat 18 on the condensate outlet port 412. The arrangement 400 further includes a snap over center pumping mechanism. Reference is now given to Figure 3B which shows the four bar linkage mechanism of the arrangement 400 along with the snap over center pumping mechanism. The driven link 3 is operatively connected to the snap over center mechanism through a pin joint C. The snap over center mechanism includes a biasing member 6, the actuator link 5, and a pivot joint E. The actuator link 5 is connected to a junction of the driven link 3 and the coupler link 2 via the biasing member 6. In an embodiment, the biasing member 6 is a spring. On end of the biasing member 6 is connected to the junction, while the other end of the biasing member 6 is connected to the actuator link 5 through the pin joint F. The actuator link 5 is pivotally connected to a pivot E which is a fixed pin joint. The actuator link 5 is configured to be displaced between a first stopper H and a second stopper I under the influence of the biasing member 6 such that the actuator link 5 makes a particular angle with the vertical at these positive stoppers. The arrangement 400 further comprises a steam inlet valve 7 and a steam exhaust valve 9. The steam inlet valve 7 is configured to be linearly displaced under the influence of the actuator link 5. The steam inlet valve 7 is configured to open or close the steam inlet port 414. The steam inlet valve 7 rests against a seat 8 on an operative outer surface of the steam inlet port 414. The steam pressure acting over the steam inlet valve 7 itself keeps it closed against the seat 8. The steam inlet valve 7 is constrained to move linearly by the sliding joint G. The steam exhaust valve 9 (as shown in figure 3C) is connected to the actuator link 5 in a plane parallel to that of the steam inlet valve 7, and is configured to be linearly displaced under the influence of the actuator link 5. The steam exhaust valve 9 is configured to open or close the steam outlet port 416. Further, the steam exhaust valve 9 rests against a seat 10 on an operative inner surface of the steam outlet port 416. The steam exhaust valve 9 is constrained to slide on to the steam exhaust valve seat 10 by the sliding joint K. It is also constrained to be pushed by the actuator link 5 as it moves from one position to the other. During the beginning of condensate filling, the buoyant body 406 rises as the level of condensate in the vessel 402 rises. The condensate flows through the condensate inlet check valve 212 into the vessel 402. The four bar linkage mechanism is proportioned such that the condensate outlet valve 12 is open against the trap seat 18 corresponding to the condensate outlet port 412 and the lower level L1. The crank 1 correspondingly rotates in the upward direction amplifying its displacement through the coupler link 2 into the angular displacement of the driven link 3. The driven link 3 in turn stretches the biasing member 6 as it biases the actuator link 5 against the stopper H. As the buoyant body 406 continues to rise, the biasing member 6 is continuously stretched. As shown in Fig 4B, when the buoyant body 406 reaches the upper level L2, the displacement of the biasing member 6 reaches its maximum value. Any increase in the level of the condensate within the vessel 402 beyond this point causes the actuator link 5 to tip over and rotate to its second stopper I. Figure 4B illustrates a schematic view of the four bar mechanism including the snap over center and trapping mechanism (upper level position) at upper snap point with motive steam inlet port 414 closed and the steam outlet port 416 open. Referring to the Figure 5A, the actuator link 5 rotates about its pivot E and reaches the stopper I. As the actuator link 5 rotates from its lower stopper H to the upper stopper I, it simultaneously opens the motive steam inlet valve 7 against the steam motive pressure P1 and closes the steam exhaust valve 9 against the seat 10. As the actuator link 5 rests on its upper stopper I, the displacement of the biasing member 6 reduces to its lowest value. Steam flows into the vessel 402 and steam pressurization begins. When the pressure in the vessel 402 becomes marginally greater than the back pressure P3, the steam pressurization ends and condensate pumping begins. The condensate outlet check valve 222 opens against the back pressure P3. The condensate flows out of the outlet condensate check valve 222 through the condensate outlet port 412. As the condensate level within the vessel 402 decreases, the buoyant body 406 begins to move downward by virtue of its weight, and correspondingly the crank 1 rotates to move the driven link 3 in the downward direction such that biasing member 6 again stretches but is biased against the upper stopper I. This continues up to the point where the biasing member 6 again reaches its maximum displacement, as shown in Figure 6a, where the corresponding condensate level is the lower condensate level L1. Any reduction of condensate level below this point will cause the actuator link 5 to rotate over to its lower stopper H. This signals the end of condensate pumping. As shown in Figure 6A, as the actuator link 5 rotates, it simultaneously opens the steam exhaust valve 9 against its seat 10 and lowers the motive steam inlet valve 7, allowing it to seat on the seat 8 thereby closing the steam inlet port 414. This allows the steam from the vessel 402 to escape through the exhaust valve seat 10, thus beginning the steam exhaust. When the pressure in the vessel 402 becomes equal to the pressure P2, the steam exhaust is completed and the condensate filling begins again, and the whole cycle continues in this manner. The snap over center mechanism is proportioned in such a way that the buoyant force required to overcome the buoyant body weight and the biasing member load increases as the buoyant body 406 rises and sweeps the angle ?1. Further, the buoyant force required, as the buoyant body 406 moves in the downward direction, first decreases reaches its lowest value and then increases to a particular value. Referring to Figure 7A and Figure 7B, the isometric view of the four bar linkage mechanism with various links numbered similar to those in Fig 3A to 6B, only with subscripts a are shown. For example, the crank 1 is numbered as 1a. Additionally the mounting bracket 408 for the mechanism linkages and the mounting base 410 onto which the mounting bracket is bolted is shown. The mounting base houses the motive steam inlet and steam outlet ports (not shown in figure 7A and 7B). Figure 8A, Figure 8B, and Figure 8C show a detailed views of the steam inlet valve 7a, and the actuator link 5a at three positions namely position 1, position 2, and position 3. Each of these positions corresponds to the instant when the actuator link 5a rotates to close the steam outlet port (not shown) and open the steam inlet port 414. Particularly, each position depicts the relation between the position of the actuator link 5a and the steam inlet valve 7a. The actuator link 5a has a first cam CP1 configured to abut a follower FP1 configured on the steam inlet valve 7 when the actuator link 5 is displaced from the first stopper H to second stopper I. Position 1 refers to the instance when the cam profile “CP1” on the actuator link 5a just comes into contact with the follower profile “FP1” along the area indicated by D” with the stem of the steam inlet valve 7a. Position 2 refers to an instance where the stem has been lifted adequately to maximize the flow rate through the steam inlet seat not shown. The area of contact indicated by D” previously now shifts to a line of contact as indicated by E”. Position 3 refers to the instance when the steam inlet valve 7a has been lifted to the maximum and the actuator link 5a has reached its upper stopper. The line of contact previously indicated by E” now shifts to point of contact shown as F”. In each position, the distances A”, B”, and C” are the distances between the actuator link 5a pin joint and the point of application of the opening force on the steam inlet valve 7a at different instances of time. The cam and follower profile can be so designed such that the distances B”