## 3 Results and Discussion  
This section presents the results and discussion on the novel design of a globe valve with compact geometry using an extending mechanism. In the current research, the performance of the valve design was analyzed with ANSYS and the experimental prototype for the position and force analysis of the valve mechanism was followed by the flow analysis of the valve. A comparative study of the results obtained from the simulation, experiment, and original design was done to evaluate the performance of the new valve design. Figure 8a shows the comparison of the output displacement at the disc from the simulation and experiment. Results were similar with negligible difference. The difference in values was due to the tolerance of joints in the mechanism and surface roughness, due to which the movement of the joints was not very smooth. Figure 8b shows the comparison of the displacement required at the input to produce the required output at the disc. The input displacement required for the new design was significantly less when compared to the original design. In contrast to the conventional design where the input displacement was the same as the output due to the rigid shaft, the applied mechanism reduced the required input while maintaining the output. A decrease in the required input displacement decreased the required length of the bellow as less displacement will need less bellow length, which in turn will reduce the overall valve structure. It can be observed, with the application of the six-bar linkage, the required displacement at the input was about 2.5 times less in magnitude when compared to the required displacement in the original design. Tables 2 and 3 show the comparison of the output between the simulation, experiment, and original design. Figure 8: (**a**) Comparison of position analysis from the simulation and experiment. (**b**) Input displacement comparison of the original and new design. Figure 7: Experimental analysis setup. A comparison of the force required to operate the valve for the original, simulated, and experiment design is shown in Figure 9a-e. Figures show the comparison of the actuation force at different valve opening positions for pressure ranging from 10 to 50 kPa. As seen from the figures, the force required for the new design was significantly higher than the original design. For the original design, the force required to operate the valve was assumed to be same as the force acting on the disc due to the fluid pressure. The force required by the mechanism as obtained from the simulation was eight times more than that of the original design whereas for the experimental, the required force was up to ten times more than the original. The difference in the simulation and experiment could be explained due to the tolerance and friction in the mechanism in the joints which make the movement unsmooth. The difference between the force required for the new design and original design was due to the force distribution in the linkages of the mechanism. Force in the reciprocating shaft was assumed to be equal to the pressure acting on the disc. An equal and opposite reaction force was required at the input to operate the valve. In the current design of the valve, the disc was attached to the input handle via the reciprocating shaft. Assuming that the shaft is rigid, the reaction force produced at the output (disc) is equal to the input force applied. Therefore, the force required to operate the valve is equal and opposite to the force being applied on the disc due to the fluid pressure. The results showed that the force required to operate the valve increased with the increase in fluid pressure and also increased as the valve was closed. The original, simulation, and experiment all showed the same trend in actuation force. Table 4 shows the actuation force for the valve at different inlet pressures. A comparison of the flow coefficient for the original, experimental, and simulated design is shown in Figure 10 at different pressure inlets.