Products First Flush Washers - Black
First Flush Washers - Black
(Incl. GST)
The set of black slow-release valve washers for your First Flush Diverter, with hole sizes ranging from 0.25mm to 1.00mm. Black washers drain more slowly than the red set, so they're the right choice when you have a smaller diversion chamber or want to perform first flush diversion less often. To replace, simply unscrew the black hose fitting at the end of your First Flush Diverter and swap in the new valve.
Features and benefits
Tune your drain rate
The set covers hole sizes from 0.25mm to 1.00mm. Smaller holes drain more slowly, letting you tune the reset time between rainfalls to suit your chamber size and rainfall pattern.
Drain rates by hole size
In vertical installations, the 0.25mm hole drains around 1.6 litres per hour, 0.5mm around 4, 0.75mm around 11, and 1mm around 13. Horizontal installations drain at roughly half these speeds.
Easy to replace
Unscrew the black hose fitting at the end of your First Flush Diverter, swap in the new valve, and fit the washer with the side marked "TOP" facing up. Start with the smallest hole size and try a larger one if you experience blockages.
Suits smaller diversion chambers
Slower drain rates make this set the right choice for smaller First Flush diversion chambers, or where you want to perform first flush diversion less often.
Product Support resources
Frequently asked questions
What's the difference between the black and red first flush washers?
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