UPSIDE-DOWN MICRO-EMITTERS
HANDBOOK
39
ACCESSORIES AND COMPLEMENTARY PRODUCTS
AD valve models and performance
Model Pin code color Opening pressure* (bar) Shut off pressure* (bar)
15/0.7
Blue
1.5
0.7
20/0.9
Purple
2.0
0.9
30/1.5
Green
3.0
1.5
40/1.8
Orange
4.0
1.8
*at this pressure, all the valves will be open/close
NOTE
Netafim™ defines opening/closing pressure when all emitters are open/closed (some of the
competitors state average data).
NOTE
Due to minute manufacturing differences between the components of each of the accessories
(especially in the production of springs) there are very small differences between the opening/
closing pressure of these accessories. These differences are usually so small that they are not
visible to the naked eye. This phenomenon may become visible and therefore unacceptable,
especially when closing the water supply to a distribution pipe of a system that was not designed
optimally.
If the hydraulic system is larger than required by the actual need, some of the AD valves will close - the
pressure in the line will rise - other AD valves will "feel" a higher pressure and will not close until the
pressure in the line drops to the planned level. This phenomenon occurs both with rigid and flexible pipes
(even more intensely with flexible pipes).
When the hydraulic system is properly designed to suit the actual flow rate through the distribution pipes,
this phenomenon is usually impossible to observe because it happens very swiftly.
Stabilizer
The main function of the stabilizer, which is threaded on the micro-tube, is to help
maintaining the verticality of the emitter.
It is supposed to reduce the effects suffered by the micro-tube due to its lack of
straightness and/or the twisting of the distribution pipe and/or errors in location of
the holes around the circumference of the distribution pipe.
The heavier the stabilizer, the better its improvement of the hanging stand verticality
resulting in a fuller implementation of the emitter's designed water distribution
uniformity.
Netafim™ has developed and manufactures a stabilizer made of a high-specific-
weight plastic and therefore weighs more (relative to competitors' stabilizers) and
thus helps to ensure that the emitter is stable in its intended location.
In addition, Netafim's stabilizer has two dents at its extremities serving as an aid to the system assembly
or operation. These dents suit the geometric shape of Netafim's connectors. Inserting the connectors into
the dents allow the installer/operator to apply more force in a convenient and very fast manner without the
need for other tools.
Head loss in AD valves
Flow rate
(l/h)
Head loss
(bar)
50
0.05
70
0.07
90
0.10
120
0.16
160
0.28
200
0.38
Tool
Tool
Summary of Contents for COOLNET PRO
Page 47: ......
