When the fluorine-lined check valve is actually operated, whether it is fully opened can generally be determined by the opening height. Normally, when it is fully opened, its opening height is about one third of the nominal diameter. Therefore, in practical applications, we must pay attention to the formation of the valve flap, and then determine whether it is fully open. In addition, its flap is generally used as an opening and closing piece, and its shape is usually a plug shape. The sealing surface is generally flat or tapered.

In the actual operation of fluorine-lined check valves, the general sealing performance is maintained by relying on the force of the valve. Since the stem and the packing work at the time of operation, a certain degree of friction will occur, so the stem must be thick enough to avoid accidental bending of the stem. Therefore, when selecting a PTFE-lined valve, it is necessary to select an appropriate stem diameter according to the requirements.