Got into a disagreement with my housing inspector (selling my house). He
was taking readings of my water pressure at various locations. Suggested
that I adjust my regulator for a little more pressure. Good idea, but I
told him that as long as her is going to read 'static' pressure only, he is
going to get the same reading no matter how far he is from the source (as
long as it's the same elevation). At least that's the way it was 40 years
ago (hydraulics classes) unless things have changed. Which leads me to the
following question:



Is the regulation of pressurized air much different? In a simple water
regulator the deed is accomplished by merely restricting the flow. In other
words, the regulator on the downhill side of my compressor could be set to
80 psi while my storage tank is reading 130 psi. I realize that I am going
to get 80 psi under flow conditions. But, do I really have 130-psi static
until I actually request the air flow (pull the trigger on my sandblaster,
for instance) at which time the dynamic pressure (pressure under requested
flow) reduces to 80 psi.



If the above is INCORRECT, then, somebody please explain how the reducer
works. How is it able to reduce the static pressure? If the above is
CORRECT, then somebody please explain how my nail gun works. If I shoot
nails at a slow rate (let's say, one every 5 seconds), my gun is basically
working on whatever static pressure is sitting behind the piston therein.
That static pressure should be the full pressure and not the reduced
pressure. Maybe there is a slight component of flow when you shoot a single
nail, but I have found otherwise. e.g., I can plug in my nail gun to a
short hose (say 10 feet), then fire a single successful shot after having
shut off the air supply on the uphill end of the short hose. Since there is
little or no flow, the gun must fire because off static pressure.



If anybody can explain the above, I would greatly appreciate it.



Ivan Vegvary

"Ivan Vegvary" wrote in message
news:L0%Xa.50908$Oz4.14553@rwcrnsc54...
If the above is INCORRECT, then, somebody please explain how the reducer
works. How is it able to reduce the static pressure?

AFAIK, it works by metering with say a needle valve, actuated by an
adjustable diaphragm which senses the output pressure, such that if
perssure falls, the valve opens, and conversely if pressure rises it
shuts it off. If this valve can close fully with no leakage then it
should be capable of holding with no load.

Tim

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms

"Ivan Vegvary" wrote in message
news:L0%Xa.50908$Oz4.14553@rwcrnsc54...
Got into a disagreement with my housing inspector (selling my house). He
was taking readings of my water pressure at various locations. Suggested
that I adjust my regulator for a little more pressure. Good idea, but I
told him that as long as her is going to read 'static' pressure only, he
is
going to get the same reading no matter how far he is from the source (as
long as it's the same elevation). At least that's the way it was 40 years
ago (hydraulics classes) unless things have changed. Which leads me to
the
following question:



Is the regulation of pressurized air much different? In a simple water
regulator the deed is accomplished by merely restricting the flow. In
other
words, the regulator on the downhill side of my compressor could be set to
80 psi while my storage tank is reading 130 psi. I realize that I am
going
to get 80 psi under flow conditions. But, do I really have 130-psi static
until I actually request the air flow (pull the trigger on my sandblaster,
for instance) at which time the dynamic pressure (pressure under requested
flow) reduces to 80 psi.



If the above is INCORRECT, then, somebody please explain how the reducer
works. How is it able to reduce the static pressure? If the above is
CORRECT, then somebody please explain how my nail gun works. If I shoot
nails at a slow rate (let's say, one every 5 seconds), my gun is basically
working on whatever static pressure is sitting behind the piston therein.
That static pressure should be the full pressure and not the reduced
pressure. Maybe there is a slight component of flow when you shoot a
single
nail, but I have found otherwise. e.g., I can plug in my nail gun to a
short hose (say 10 feet), then fire a single successful shot after having
shut off the air supply on the uphill end of the short hose. Since there
is
little or no flow, the gun must fire because off static pressure.



If anybody can explain the above, I would greatly appreciate it.
^^^^^^^^^^^^^
You are right about the water pressure in the lines of your house. If there
is no flow, the pressure at any point is the sum of the static pressure at
the highest point and the hydrostatic pressure due to elevation.

A pressure regulator is basically a valve, held open by a spring, and
closed by a diaphragm that is subjected to the downstream pressure. When
you turn the screw on the front of the regulator, you are compressing the
spring, causing the valve to open. This permits flow of fluid in the system
(water, air, oxygen,acetylene, or whatever) through the valve, increasing
the downstream pressure. When this pressure reaches the set-point, the
valve closes, and the downstream pressure stops rising, even when there is
no flow.

I hope this clears it up. I don't understand your question about the
nail-gun. It operates on the regulated pressure.