No it gushes out a lot faster than that, it's like jumping into a swimming pool, you have to be quite adept at the job to take on a live swap and if it's at the base of a kitchen unit forget it. I would change ball style service valve to a stop cock anyway, ball valves are rubbish anyway, get stuck when you need them and leak after you've used them. Stop cocks are well designed piece of kit cheap to buy and work for a very long time, never fully open any tap, turn it back slightly, so it doesnt stick. Don't put it in a stupid little hole at the back of the kitchen unit where you can't get a purchase on it at a future time you need it and it is a little stuck for non use. Your stop cock is your friend give it pride of place.
You have lead pipe coming in this isn't named by diameter but by weight of lead, 7lb is most common around here for household, has a half inch diameter hole in centre and is usually wipe jointed to copper as it enters house, sometimes directly wipe jointed to stop cock, which makes life difficult for you guys.
If there is decent length of 1/2" compression nut connecting to your ball type valve undo it and attach a stop cock instead, accept the fact water will wet you through and your kitchen once and for all but never again.
If you were stupid enough to have laminated flooring in your kitchen that's your lookout for stupidity. I would never fit laminated floor in a litchen or bathroom whatever the makers say.
If you were sensible and had a waterproof floor, you have nothing to worry about.
