Shako PU220AR solenoid value precision

This Shako valve and brass nozzle performs EXCELLENTLY with pulse duration 7 ms up to 20 ms with small nozzle (barbs for 1/8 inch tubing, 0.093" nozzle ID), and is extended above 20 ms pulse with the larger nozzle (barbs for 3/16 inch tubing, 0.125" nozzle ID). See tests below. This valve is simply in a very different quality class. Very consistent, like precision timing was expected to be. Now I can make a little change in timing, and see a little change in the drops - the drops are actually related to the timing.

The small nozzle does start getting extra scattered drops at about 25ms (see below), but a 3/16 inch (tubing) nozzle becomes right then. An even larger nozzle for 1/4" tubing can work from 50 to 70ms, but is a little more messy, and more head height may be necessary. The 1/8" nozzle shown cut to half length also worked fine, but I did not notice any benefit from it.

The StopShot Mariotte siphon is used here with pressure of 11 inches of head, using a 5 inch connecting tubing.

Only change below is pulse length. Shown is drops of 7 to 30 ms valve pulse, which were using the 0.093 inch ID nozzle for 1/8 inch tubing. Then the multiple drops started, so 20-30 ms were repeated, and on to 50 ms, after changing to 0.125 inch ID nozzle for 3/16 inch tubing.

You would have to see the others (messy, extra drops which spoil things) to realize how unbelievably wonderful this valve looks.

Three samples each, with same pulse length (time valve is open). All are 2 drops with 60ms Toff between them (Toff, time valve is closed)

7 ms Pulse Small 1/8" nozzle
8 ms Pulse
9 ms Pulse
10 ms Pulse
12 ms Pulse
15 ms Pulse
20 ms Pulse
25 ms Pulse
30ms Pulse
Now, this was very clean and boring (and ideal), until multiple drops started above. So restarting at 20 ms Pulse below, using 0.125 inch ID nozzle for 3/16 inch tubing. Not too bad really, and lesser valves can be greatly more messy than this, at any pulse duration. Believe me, you'd have to see those to appreciate this, but the extra drops mess up the collisions. This one is how we always thought it ought to be.
20 ms Pulse
25 ms Pulse
30 ms Pulse
35 ms Pulse
40 ms Pulse
45 ms Pulse
50 ms Pulse

Same thing, repeated with only change of additional Mariotte siphon pressure of 13 inches of head, equivalent of using a 7 inch connecting tubing. More pressure is better at minimum pulse, but it causes worse scatter drops at maximum pulse. The drop falls faster with more pressure, so this try uses 20ms less timing between sensor and flash.

7 ms Pulse Small 1/8" nozzle
8 ms Pulse
9 ms Pulse
10 ms Pulse
12 ms Pulse
15 ms Pulse
20 ms Pulse
25 ms Pulse
Multiple drops starting again above, so restarting at 20 ms Pulse below, using 0.125 inch ID nozzle for 3/16 inch tubing
20 ms Pulse
25 ms Pulse
30 ms Pulse
35 ms Pulse
40 ms Pulse
45 ms Pulse
50 ms Pulse

www.scantips.com

Shako PU220AR solenoid value precision

Three samples each, with same pulse length (time valve is open). All are 2 drops with 60ms Toff between them (Toff, time valve is closed)