thanks JD sediment removal filter sorry, not calcite. my setup is as follows. tap, pressure limiter, 350 kpa. non return on/off valve, then john guest line into sediment filter, then chemical filter, then splits t junction into small sink faucet tap for filtered water and also off to espresso machine. Seeing as my machine is in a as new condition and 12 months old I assume it must be the pressure valve is out. It does restrict it but it is on 4 1/4 bars on the machine. But shots are pulled exactly right, 9 bars roughly as factory preset. My PLV is new, from the company that supplied me the water filter kit. I will replace it to be safe. A pain but will do it. I have no choice re a few hose clamps. I have john guest line on the filters but the line to the machine is already built into the wall from 12 months ago and cant be replaced. Its as new teflon/pvc. good quality. but I had to join the blue john guest line to the teflon line, no choice and the only way is to hose clamp, that I know off anyway. I cant afford plumbers all the time, saying that I was advised by them to use hose clamps. I asked 3 for solutions, and also my local plumbing store. All suggested hose clamps. its not a long long term setup ,but maybe 12 months. No leaks but I understand your warning. If we go out I am turning it off. I have a simple washing machine gate valve for on off. Its a new model with a half turn shut off. But under sink so I guess I wish I didnt have too. I have re checked my flow rate from the machine and its about 2 and half litres a minute but it still shows 4 1/4 to 4 1/2 kpa. Thankyou for the advice. I am at least glad to have the sediment filter protecting my machine. its great having to not top up the tank anymore. cheers MARC