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UPSIDE-DOWN MICRO-EMITTERS
HANDBOOK
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ACCESSORIES AND COMPLEMENTARY PRODUCTS
Introduction
Netafim™ developed a unique selection of accessories and complementary products exclusively designed
to provide a comprehensive solution for the UD micro-sprinkler/emitter system.
These products are designed to greatly improve the ease of use and the performance of the UD micro-
sprinkler/emitter system while facilitating and simplifying assembly and maintenance operations.
Anti-drain (AD) valve
This product is designed to ensure that delivery and distribution pipes will not be
emptied when the system is in an inactive state.
If AD valves are not installed, at the end of each irrigation pulse the distribution
pipes (which are usually above the emitters) will be drained and spill over the
crop, possibly leading to severe damage. Thus, the distribution pipes will
require refilling at the start of the next irrigation pulse. In such a case, not all
the emitters will start working at the same time, and certainly not under the
pressure required for efficient water distribution, resulting in a different quantity
of water being sprayed from each emitter.
The AD valve is usually installed above and near the emitter to prevent the micro-tube from being emptied,
but in rare cases, they can be connected directly to the distribution pipe. In this case, it should be taken
into account that the volume of water in the micro-tube (a relatively small amount) will drip through the
emitter onto the crop at the end of each irrigation pulse.
Netafim™ offers an assortment of models, identifiable by the color of the pin protruding above the product
cap. Each model will open (allow flow) when water pressure in the system reaches the planned level.
Choosing the appropriate AD valve model:
A) Ideally, the appropriate AD valve is one that opens at a pressure the closest to the
recommended pressure of the emitter installed downstream from it.
EXAMPLE
If the CoolNet Pro™ has been chosen, the best choice is a model that will open at
a working pressure of 4.0 bar because as soon as it opens and the water starts to
flow to the emitter it will "sense" the recommended working pressure and therefore
function perfectly.
If the SpinNet™ has been chosen, the best choice is a model that will open at a
working pressure of 2.0 bar (for the same reason).
B) Although in some cases, even when the system is designed to the optimum,
if the farmer is concerned of possible pressure irregularities or the system's
inability to provide a consistent level of pressure to all the emitters as planned, it is
recommended to choose a model with a working pressure level one below the ideal
match. This will ensure that even if the planned working pressure does not reach all
the emitters, the AD valve will open and allow irrigation at a pressure level lower than
the planned working pressure. Although not ideal by any measure, in particular cases
it is the preferred solution.
Summary of Contents for COOLNET PRO
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