The document summarizes experimental studies on pressure drop in a sinusoidal plate heat exchanger with varying corrugation angles. Three plate heat exchangers were fabricated with corrugation angles of 30, 40, and 50 degrees. Experiments with water flow showed that pressure drop and friction factor are affected by the corrugation angle. Pressure drop increased linearly with Reynolds number and was highest for the 50 degree angle. Friction factor decreased linearly with Reynolds number on a logarithmic scale and was lowest for the 50 degree angle. The results indicate that higher corrugation angles induce more turbulence, increasing pressure drop but decreasing friction factor.