thanks Shark
looking at that has put my mind at rest .
the little canister called ISC valve silencer (no 12 in the diagram ) is shown conected to the spigot in question which is open to the air .
there is no silencer canister or hose on my DF70 but thats probably because that link is for American spec motors and they tend to fit stuff that we don't need .
Thanks again Proper Job