If the foam is to thin ( like milk ) it runs off to quick, it needs to be a certain thickness so it can dwell,you can adjust the one i posted so you can get the perfect thickness you want.
And its not just the lance,my kranzle pressure washer foams far better than my nilfisk pressure washer with the same foam lance,the nilfisk no matter how much you adjust it you cant get it as thick and when using my kranzle.