Difference between revisions of "Honking"
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When we say a valve "'''honks'''", it means that it vibrates open and closed; the cycle is like this: | When we say a valve "'''honks'''", it means that it vibrates open and closed; the cycle is like this: | ||
| − | # The | + | # The diaphragm/piston unseats, and due to the increase in differential force caused by the "new" area, is pushed back rather quickly. |
| − | # Air pressure in the pilot volume starts to build, as the piston | + | # Air pressure in the pilot volume starts to build, as the diaphragm/piston moves, compressing it. |
# The momentum of the diaphram/piston keeps it going past the point where the pressures on both sides of the diaphram/piston are equal. | # The momentum of the diaphram/piston keeps it going past the point where the pressures on both sides of the diaphram/piston are equal. | ||
| − | # The higher pressure in the [[pilot]] volume now accelerates the piston | + | # The higher pressure in the [[pilot]] volume now accelerates the diaphragm/piston back to where it started... and you can follow the steps from #2, but with the pressure in the pilot volume dropping. |
| − | If a valve is honking, it is most likely not | + | If a valve is honking, it is most likely not opening fully, and this will decrease performance. Honking is often interpreted as a sign that you are using a [[pilot valve]] that is too small, and this occurs most often in un-[[Sprinkler valve modification|modified]] [[sprinkler valve]]s due to the extremely small stock pilot. This pilot also vents to the barrel instead of the atmosphere, which increases feedback. |
[[Image:Honk.GIF]] | [[Image:Honk.GIF]] | ||
Revision as of 07:35, 27 October 2005
When we say a valve "honks", it means that it vibrates open and closed; the cycle is like this:
- The diaphragm/piston unseats, and due to the increase in differential force caused by the "new" area, is pushed back rather quickly.
- Air pressure in the pilot volume starts to build, as the diaphragm/piston moves, compressing it.
- The momentum of the diaphram/piston keeps it going past the point where the pressures on both sides of the diaphram/piston are equal.
- The higher pressure in the pilot volume now accelerates the diaphragm/piston back to where it started... and you can follow the steps from #2, but with the pressure in the pilot volume dropping.
If a valve is honking, it is most likely not opening fully, and this will decrease performance. Honking is often interpreted as a sign that you are using a pilot valve that is too small, and this occurs most often in un-modified sprinkler valves due to the extremely small stock pilot. This pilot also vents to the barrel instead of the atmosphere, which increases feedback.
(Note the upwards trend in the valve position.)
