Quote:
Originally Posted by Worth1
I would like to add something.
If anyone is using a sprinkler system, drip system or fertilizer injection system they need to know something.
For the first two you need at least a double check back flow preventer.
The last you need something better like a vacuum breaker of reduced pressure back flow preventer.
Those little cheap plastic check valves are junk and should never be used.
A good brass vacuum breaker at the faucet is much better and here where I live they are required.
Remember it is all our responsibility to protect our water supply. 
Here is a link to why and where.
http://www.irrigationtutorials.com/i...ow-preventers/
Worth |
For the first two you need at least a double check back flow preventer.
The last you need something better like a vacuum breaker of reduced pressure back flow preventer.
It depends on your system layout. A double check back flow preventer is an expensive device and usually only required when using a municipal water supply and injecting chemicals. A vacuum breaker directly after the faucet with a one way swing check valve is all that is really necessary when on a well. If your faucet is the highest point in the system then there is even less to worry about.
Municipalities need to worry about this stuff because most outside faucets are hooked directly to the main line that comes in to the house. If you are injecting chemicals and they suffer a sudden pressure drop the pressure/water in your system could allow for back syphoning to occur and draw chemicals into the municipal water supply.
On a well there is not usually a back syphoning problem to worry about. If the system is designed properly with air vent breakers at the high points then water should never cause a syphoning effect unless the whole system is under water from a flood or some such thing.
A lot of the "gear" that is sold is designed for businesses who are dealing with much nastier stuff than fertilizer.