The FTIV is normally placed between the fuel tank and the activated carbon filter and controls the flow to the filter. In addition, additional valves are required to open and close the complete system, for example during OBDII tests. The FTIV is a normally closed valve that can be opened electrically as required. It has two mechanical bypasses which reduce the built up pressure or underpressure as soon as a pre-defined threshold is exceeded. In addition, the volume flow of fuel vapors in the direction of the activated carbon filter can be limited to a maximum value by a flow limiter. The valve meets the non-leakage and flow requirements of modern fuel tank systems with a compact design and low weight.
Thanks to the modular build, it is possible to equip the FTIV with any functions required by the customer. For example, there is an option in which the valve is closed without current and only has an overpressure bypass.
Another variant of the valve, the FVV, is normally open. This type can be closed by simply applying power, if desired, so that the path of the fuel vapors in the EVAP system is sealed, for example, during an OBDII test.