# How to find velocity of water flow and $Q$ if I know static pressure at the end of the pipe of known diameter?

I have a pipe. At its end I have mounted pressure meter. Of course there is no circulation. Water pressure meter is a kind of stopper for water. I know diameter of the pipe, and I know its pressure in static. How can I find velocity of water and its quantity $Q$ in that particular place (where pressure meter is) if I remove pressure meter and continue existing pipe with pipe of the same diameter?

As I understand $$Q = v(velocity) * S.$$ Then... I need velocity to count Q.

• Hi John Smith, 3 comments: 1) What is S? Is that the pipe area? 2) You say that 'pressure meter is kind of a stopper for water'. Does that imply that the water is not flowing, i.e. this is a static situation? 3) Don't forget, as I mentioned in this answer to your other question, that Bernoulli's equation is not valid for pipe flow (you applied the tag for bernoulli equation). – Time4Tea Aug 28 '18 at 1:38
• I think the answer to this is basically the same as the answer I gave to that other question. – Time4Tea Aug 28 '18 at 1:55 