View Full Version : Water Loss?

06-30-2004, 12:05 AM
Seeking technical information on water loss calculations based on broken 1" sprinkler heads. System is 2" into 1"
- Loss per min/hour measured in gallons.

Same thing for an 1/2 system.



Ground Master
06-30-2004, 02:59 AM
whats a 1" sprinkler head?

06-30-2004, 02:02 PM
By 1" -I meant products like I/25 and I/31 from hunter. Sorry I should have been more specific.

Really if you want to get technical It really doesnt matter what size head is installed, I am looking for info on how much water is lost on a 1" line broken at the sprinkler head location. The infrastructure is made of an 2" main for the feed of an1" zone.

06-30-2004, 02:40 PM
Or the I-90 or I-60

06-30-2004, 03:36 PM
Thats all relative to the GPM available to the system itself.

06-30-2004, 03:37 PM
You have a widew open line. Your loss is actuall volume system is producing.

If your point of connection is at a certain gpm, that is what you are wasting

Instant Rain
07-01-2004, 11:23 PM
flow is a function of pressure and friction. the more the pressure the more the flow. i suggest attaching the broken head directly to a flow meter as close as you can get it with a pressure regulating valve as adustable and a water source. pressure gauges should be attached to the discharge side of the meter and inlet of the meter. the final assembly water source, press reduce valve, gauge, flow meter, gauge, head.with as little pipe in between then test flow at different pressures recording what pressures = what flows. then graph it. if you know the lay out of the pipe length and diameter and starting pressure. you can use standard friction loss charts to find waste. is this data to be used for marketing. i would be intested to know the results.

07-01-2004, 11:43 PM
who cares about all that crap? fix the broken head.

07-02-2004, 04:06 PM
greenway- you should care- for one thing if the head is broken is it going to page you and let you know- no its not. I am asking for this data so that we have solid statisics for our customers who are mostly of the state and government population.

If anyone knows of any tables or charts out there showing GPM on most standard instalations thats is what we are looking for. We do have a test lab with flow meters and such but would like to hear from people out in the field in all types of applications.

Instant rain- thanks for the post, if I get anymore info I would be happy to pass the results on.. you can send an email to me with your contact info. matt@watersav.com

07-02-2004, 06:51 PM
sorry, i was having a bad day and i didnt and understand the purpose of your question. i usaully dont write on web sites cause i dont know anything.

07-06-2004, 12:33 AM
to correct Instant Rain, Flow is NOT a function of friction and pressure, but rather of Area and Velocity (Q=VA). Pressure is a measurement of energy and friction is a loss of energy, but neither is a function of flow........

Instant Rain
07-06-2004, 09:55 PM
Thank you Gringocl. You are correct. Flow is a measurement of movement of a specific volume over time. If one knows the velocity of that fluid and the area at the point that measurement is taken, one may know the flow. I apologize for being so general.
I wanted to help our friend by explaining that the pressure (energy) and friction (the conversion of the pressure energy into heat) are two factors used to find flow. After all pressure is part of what gives the water velocity. And the friction is what takes that velocity away. Imagine a very long pipe and a water source under pressure. even if that pressure was very high and the diameter of the pipe very large. The pipe could be made long enough that most energy was lost and the flow would be very little. For example, 10,000,000 ft of 4” asbestos cement pipe, perfectly level with a source at 100.433 psi. The other end has an elbow with a stub of open pipe one ft long. C=140. The flow at the end would only be 5gpm.(A 6in LINE WITH AN OPEN END AND A SOURCE OF 100psi= 5GPM?) Also even if one knows the velocity and area at a given point one may not necessarily know the flow at any other given point because of the time it may take for pressure changes to travel down the line. Flow can also be measured as Acre-inches/feet per hour/day. Most of us are here to contribute, seek, or give help not mince words. Thank you again for helping me correct my error. Any body in search of friction charts can find them in the back of most irrigation product brochures.

07-07-2004, 12:08 AM
Instant Rain, I didn't mean to flame you, but just trying to help correct false beliefs about pressure and flow, etc. Things like sticking your thumb over the end of a hose increases the pressure.... I understand that forums like these are here for help and are a great asset.