Dual Check Valves are utilised for protection from cross contamination of non potable water with potable water. They are a mandatory requirement and should be fitted on all irrigation systems that are connected to the mains because Dual Check Valves effectively prevent the back-flow of potentially harmful debris. They are used in low hazard conditions such as rain water tank systems and domestic meter connections. Be aware that a regular Spring Check Valve only provides one level of back flow and there is still a risk of contamination so they are not thorough enough and a Dual Check Valve is required.
- Maximum working pressure 1200kPa
- Min. working pressure 60kPa
- Not to be used on hot water installations
- Suitable for vertical or horizontal installations
If you are unsure of the size of the valve you need, please see this link: How to measure BSP threads and PVC Pipe
|Brass Dual Check Valve 20mm||Brass Dual Check Valve 25mm|
|Type||Check Valve||Check Valve|
|Inlet Thread Size||20mm BSPF||25mm BSPF|
|Outlet Thread Size||20mm BSPF||25mm BSPF|
|Max. Inlet Pressure (kPa)||2000||2000|
|Min. Recommended Pressure (kPa)||60||60|
|Max. Recommended Pressure (kPa)||2000||2000|
Are there any safety standards my irrigation system must meet?
The main safety concern is regarding the water supply. To avoid contamination of the mains water upstream, in most municipalities, a Dual Check Valve is required at the water connection.
Do I need to use teflon tape? How much do I need to use?
Whenever you’re connecting two threaded fittings, teflon is required. The only exception is whenever either fitting has an O-ring, in this case, do not apply teflon as it may cause the O-ring to not seal correctly. The amount of teflon you apply depends on the application. In any constant pressure applications you look at up to wrapping around the thread up to 20 times, whereas in any non-constant pressure applications, like on irrigation risers, 2 or 3 times around the thread is enough.
How deep do I need to bury my pipe?
There’s no requirement to bury irrigation pipes any depth, but there are a couple of things to consider; Allow enough room to run the pipe under your sprinklers so they sit at the right height & think about going deeper to avoid damage in areas where future digging or planting might happen. 20-30cm is often deep enough.
What size pipe do I need to use?
Pipe sizing is all about reducing friction loss & allowing maximum flow to all points of your garden. There are a number of variables to consider, but in most domestic applications, 19mm Poly Pipe is the common choice. In larger areas, where you may have to run pipe 30-40m to the start of an irrigation zone, or zones with large sprinklers with high flow requirements, you may want to consider upping your pipe size to 25mm of more boost that flow output.
What type of pipe should I use on my irrigation system?
The type of pipe you use depends on the water pressure of the application. For example, in any application under constant mains pressure like before your Irrigation Valves, you’ll need pipe that can cope. This rules out Low Density Poly Pipe & you’ll need to use something like Class 12 PVC or Metric Poly Pipe, these typically have a rating of Class 12, or PN12 which translates to being able to cope with 1200kPa. For irrigation lines after the valves in most domestic applications, Low Density Poly Pipe is ideal. In this situation, the operating pressure is much lower because the water is able to escape out of the operating sprinklers or drip tube & once the valves shut off, there is no static pressure build up.
Why should I buy from an Australian website?
We get any number of calls from people across the country who've bought from overseas & have problems. From electrical output problems to thread compatibility problems & other problems that we aren't able to help with!
By buying from SunshowerOnline, right here in Australia, you can be sure that your warranty issues are covered, that compatibility & compliance isn't an issue & that you'll be able to get helpful after service advice.