rxmnt I guess it’s worth thinking of it like a parachute. I used to fly gliders back in the day and you always had a good parachute, they cost a lot of money and in my case were individually owned. You bought it and hoped you would never need it….but if you did, then it’s super handy to have one!
The safety system for sure isn’t as essential as a parachute would be if something goes wrong, it’s not cheap and if you are careful with the lever as people have been for more than 60 years, you “should” never have a problem.
It works in 2 situations
- During a shot the portafilter comes off
- During operating the lever to make a shot, it slips from your hand.
In the first, the cup will still break, you will get sprayed with coffee and the drip tray might get dented (cover is easily replaceable and cheap). The initial pop of water will be there, but then the flow is slightly more limited as the lever goes up slowly.
In the second as long as there is pressure showing if the lever slips from your hand, it will go up slowly. If there is no pressure showing, then it’s going to come up rapidly until it has come to the point where pressure is made assuming the group isn’t yet empty. e.g. in the first 20/30 degrees of the pull there will be little to no water in the group and it will come up fast. This isn’t normally a risk because the lever is well away from you. The shock may do damage to the machine though (or it may not)
The place were the lever is more likely to slip, is the transition point between the lever having moved down much further and the slight change of hand/arm position to continue the pull. In this case it will come up slowly.
The demonstrations with no portafilter show the safety system operating, but the initial movement is a little faster than it would be in real life, because there is little pressure built in a group with no portafilter. Then you see it slow down as that pressure builds.
