The plate heat exchanger is fixed by numbers of thin and comugated heat transfer plate, harged between the carring bar on the above and the guide ber on the below. These heat transfer plate provide flow channels for two Kinds of fluid ,and the chevrons on the heat transfer plate make the turbulent flow and play a role to support the plate against the pressure difference batween the two fluids . The plate peck is to be placed batween the fixed cover and the movable cover, and fixed with tie bolts. Gasket is attached to the heat transfer plate which forms flow channel and acts seal up the fluid not to leak to the outside. The number of the heat transfer plate is determined acccrding to the amount of fhuid, physical properties of fluid, the pressure drap and thermal condition. The covers prevent the plates bended from the difference of pressure.In the assembly of plate, the surface with gasket is directed to the fixed cover and each plate is harged in direction altemately. And two fluids cannot be mied and separated by a thin plate. One fluid ahways flows in 'A" chamel and the other fluid slways flow in " B" chamel.