Volume Flow our of a fire hydrant

  • Thread starter Thread starter lord_temple
  • Start date Start date
  • Tags Tags
    Fire Flow Volume
AI Thread Summary
Calculations for water loss during hydrant flushing indicate a flow rate of 19 gallons per second from a 2.5-inch outlet at 40 psi pressure. Over 1.5 hours, this results in a total loss of approximately 105,892.77 gallons. The user expresses concern that this figure seems excessively high for flushing a hydrant. A suggestion is made to consult the Eng-tips forum for further verification and insights. The calculations appear accurate, but the user seeks confirmation on their findings.
lord_temple
Messages
6
Reaction score
0
I'm doing calculations for how much water was lost during flushing a hydrant. It is a 2.5 in. outlet and the pressure is on the system in that zone is 40 psi. It was flushing for 1.5 hours.

Q=AV

V=[(2 dP gc)/density]

density = 62.4 lb/ft^3
dP=40 psi
gc=32.2 lbm ft / lbf s^2

V=77ft/s

Q=AV=(0.0340)(77)=2.6 ft^3/s=19gal/sec

The hydrant was flushing for 1.5hrs=90mins=5400secs so...

The water lost was 19*5400=105,892.77 gals? is that right?? can you check my generals theory of my problem?? it seems to me a little bit high to loose 100,000 gals in 1.5 hours for flushing a hydrant... don't you think?
 
Engineering news on Phys.org
This was answered on Eng-tips forum. I'd look there instead of rehashing it here as well.
 

Thread 'Race car suspension Class'

Posted June 2024 - 15 years after starting this class. I have learned a whole lot. To get to the short course on making your stock car, late model, hobby stock E-mod handle, look at the index below. Read all posts on Roll Center, Jacking effect and Why does car drive straight to the wall when I gas it? Also read You really have two race cars. This will cover 90% of problems you have. Simply put, the car pushes going in and is loose coming out. You do not have enuff downforce on the right...
View full post »

Thread 'Cantilever help'

I'm trying to decide what size and type of galvanized steel I need for 2 cantilever extensions. The cantilever is 5 ft. The space between the two cantilever arms is a 17 ft Gap the center 7 ft of the 17 ft Gap we'll need to Bear approximately 17,000 lb spread evenly from the front of the cantilever to the back of the cantilever over 5 ft. I will put support beams across these cantilever arms to support the load evenly
View full post »
Thread 'What's the most likely cause for this carbon seal crack?'

Thread 'What's the most likely cause for this carbon seal crack?'

We have a molded carbon graphite seal that is used in an inline axial piston, variable displacement hydraulic pump. One of our customers reported that, when using the “A” parts in the past, they only needed to replace them due to normal wear. However, after switching to our parts, the replacement cycle seems to be much shorter due to “broken” or “cracked” failures. This issue was identified after hydraulic fluid leakage was observed. According to their records, the same problem has occurred...
View full post »

Similar threads

Calculate DN for 25 m/s Fire Hose Flow
Replies
6
Views
1K

Hot Threads

Recent Insights

Back
Top