Double Barrel D
Greenlighter
- Joined
- Apr 21, 2020
- Messages
- 9
Whats the deal with plungers in needles sucking themselves down in some rigs and not others? Why does this happen? What is some terminology I can research further?
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BDD Moderators: Keif’ Richards | negrogesic
Stimulants Needle Vacuum
- Thread starter Double Barrel D
- Start date
JessFR
Bluelight Crew
- Joined
- Oct 22, 2012
- Messages
- 14,706
Uhhh, well, as you said, it's a vacuum.
When you pull back in the plunger, if it can't draw up anything, such as the needle being clogged or something, there will be less air pressure inside the syringe than outside. Resulting in the air outside pushing the plunger back in.
Different syringes have different stiffness on the plunger, take different volumes (obviously more volume means more vacuum means more force). If the plunger has enough friction with the surrounding syringe, the force from air pressure won't be enough to push it back in.
That's about it. I believe the term you're looking for is pressure differential.
When you pull back in the plunger, if it can't draw up anything, such as the needle being clogged or something, there will be less air pressure inside the syringe than outside. Resulting in the air outside pushing the plunger back in.
Different syringes have different stiffness on the plunger, take different volumes (obviously more volume means more vacuum means more force). If the plunger has enough friction with the surrounding syringe, the force from air pressure won't be enough to push it back in.
That's about it. I believe the term you're looking for is pressure differential.