Understanding Pressure Regulators: Static & Dynamic Pressure

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Pressure regulators control the flow of gas by managing static and dynamic pressures, with static pressure measured before the regulator indicating the system's pressure when flow is minimal. A reading of 10 Bar suggests low flow velocity, and a pitot tube would be necessary to determine dynamic pressure and velocity. When the regulator is fully open, dynamic pressure is minimized, leading to higher static pressure, and a manometer placed after the regulator may show a small pressure reading if there is downstream resistance. If a valve is closed after the regulator, the manometer could read the upstream pressure, but this would depend on the regulator's position. Discussions on "pressure drop" typically refer to a reduction in total pressure, which impacts the pressure gradient in fluid dynamics equations like Navier-Stokes.
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I'm struggling to understand how pressure regulators work (and total pressure in general). I currently have an open system. So the pressurized air goes through the regulator and afterwards (after going through some further pipe), enters the atmosphere. I will assume the hydrostatic variations in pressure are negligible. The gas is incompressible and at room temperature.

I placed a manometer gauge before the pressure regulator. It measures the static pressure. It reads 10 Bar. This is where I start to get confused:

1) Does the reading of 10 Bar on the manometer before the regulator mean that the flow is barely moving? Or better worded, would I need a pitot tube the determine the total pressure, subtract the two to find the dynamic pressure and find the velocity..

2) Can anyone explain how the regulator works specifically in terms of static and dynamic pressure? I've seen plenty of explanations but they just refer to "pressure" and I need something in terms of static and dynamic to make things clearer for me. I'm thinking when the regulator is "fully open", does that mean the dynamic pressure is lowest (large area opening therefore lower velocity) and so the static pressure is highest?

3) If I placed the same manometer AFTER the pressure regulator, would it read zero bar?

4) If the manometer after the regulator had some small value of pressure, would that mean there is something downstream of the regulator (i.e. between the regulator and the atmosphere) that was causing some "resistance". Is this "resistance" restricting the dynamic pressure and therefore increasing the static pressure or is it dissipating the energy into heat and therefore reducing the total pressure? In the latter, why would the pressure gauge still read an increase in static pressure?

5) If I had a valve, placed after the regulator, which was closed, what would the reading on the manometer be? I originally thought it would read 10 Bar if the regulator was fully open. But if the regulator was half open, what would it read?

6) Just a general thing. When people refer to "pressure drop", do they mean that the total pressure has reduced? How does this effect the pressure gradient in the Navier-Stokes eqns?
 
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Yes i also need more details on it...
 
Had my central air system checked when it sortta wasn't working. I guess I hadn't replaced the filter. Guy suggested I might want to get a UV filter accessory. He said it would "kill bugs and particulates". I know UV can kill the former, not sure how he thinks it's gonna murder the latter. Now I'm finding out there's more than one type of UV filter: one for the air flow and one for the coil. He was suggesting we might get one for the air flow, but now we'll have to change the bulb...

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