Volume of water flow

1. Jan 5, 2009

berniebs

A pipe broke on the roof of a public building here in Chicago. Although I am an electrical engineer and very rusty on hydraulics and water flow, I have been asked to estimate the amount of water dumped on the roof of this building, as follows:

Diameter of the burst pipe: 3/4 in.
Water temperature: 130 degr F
Pressure: 15 lbs

Water flowed for 45 minutes before being shut off. I assume the break allowed water to flow freely from a 3/4 in diameter opening.

I would appreciate it if someone can send me the formula for this calculation. I have searched a number of PF postings, without luck.

Thanks,

berniebs
berniebs@comcast.net

2. Jan 6, 2009

tiny-tim

Welcome to PF!

Hi berniebs! Welcome to PF!

Bernoulli's equation along a streamline (essentially, KE = work done ), assuming zero speed at zero pressure:
pressure + (density)(speed)2/2 = 0

and of course flow rate = speed x area.

(For details to impress your colleagues with, see the PF Library )