looks like there are two types of torch liners with 151te welders,
on mine it a standard 4mm tube fitting
but some also have a torch liner that screws into the gas valve
Im guessing mine might be an older version as I bought mine second hand a few years ago.
if you're welding steel you'll probably be best getting a steel liner,although mine came with a nylon one.
they should be able to do aluminium, I need to use mine for aluminium in future (hopefully it'll be ok for 4mm thick), but to weld aluminium you need pure argon gas, a ptfe liner and I'll be making a new wire feed driver without serations as that should cause less problems with the aluminium wire and the serations left in the wire cut into the ptfe liners.
Ok good i know up to the point of using pure argon for alloy which wont be using that just yet.just bought 20ltr 230bar mix shield what mm extention gas hose would be suitable for joining and getting good flow rate to my new clarke 151 te .also what flow rate should i set at and is it a twin regulator i buy