In multi-flapper check valves, each plate is supported such that the hinges of the plates do not contact. This is to prevent the weight of the upper plate from interfering with the operation of the lower plate, which reduces the frictional loading of the lower plate. A support sleeve is inserted through the lower hinge, thereby providing a support surface for the upper hinge. A support collar is anchored to provide a support surface. The frictional forces acting upon the lower hinge are reduced.

Multi-fluid heat exchanger is the combination of several two-fluid heat exchangers. In a multi-fluid heat exchanger, heat transfer occurs between more than two fluids: one external and several internal fluids. The advantage of multi-fluid heat exchanger is the tight package space while maintaining the proper temperature of vehicle thermal management system. It is also a great cost saving to car manufactures and automatic suppliers.