Don't bother searching for your failed one.you can buy a new in line non return valve from any decent motor factor,my last one cost 99p.just cut the washer pipe and secure it with a cable tie on each end.
Yeh, mine's in the pipe about 300 mm after the pump, looks like a black in-line connector. As said just pick up a replacement from a motor factors, 2 minute job to install.