Split/broken/cracked/damaged PTFE guide ring on piston

here is the most common question i get asked when customers unbox their new machines

i thought i had posted a blog entry on this in the dim and distant past but i must have done a poor job of referencing it as i have spent more than an hour trying to find it with the search facility and nothing

so please commit this image to memory – this image is from the one group Bosco machine, taken some time ago, so that should give you some additional comfort that we arent making this up

1. this ring is split/broken on every single machine

2. why is it split? it has to be to get it on to the piston. the PTFE from which the guide ring is made is not elastic like the seals, it is not able to be stretched over the piston and then jump down into the seal groove. so, it must be broken/cracked/split in order for it to be fitted to the piston

3. finally, it isnt a seal, it is merely a guide ring so the brass piston does not come into contact with the bore

so when you machine arrives and you see the big cracked/split white PTFE guide ring, please remember this post; it is meant to be this way

best

reiss.